Full spectrum of metal analysis techniques!

The need for material verification is an increasingly important issue across a range of industries like aerospace, energy, rail and general engineering, since meeting the correct specifications can be critical to product performance, even public safety. The chemical analysis of metallic materials is one such procedure and it involves determining the precise elemental constituents of a test piece, to establish that it meets the required specification, to overcheck bought-in stock, to identify unknown material or to provide evidence in a product failure investigation.

The Chemical Analysis department of Keighley Labs offers an independent, bespoke service to aerospace manufacturers, the energy sector, rail industry, foundries, plating companies, galvanisers, component importers and general engineers, providing a fast turnaround and precise material verification. In addition to classic wet chemistry, it employs advanced Inductively Coupled Plasma, Atomic Absorption and Glow Discharge spectroscopy to ensure the optimum method for a particular application, as well as industry standard techniques for carbon, sulphur, oxygen and nitrogen analysis.

Part of Keighley Labs’ UKAS-accredited Metallurgical Laboratory Services capability, the chemistry department’s scope of accreditation covers an extensive range of ferrous and non-ferrous metallic materials, including iron, steel, stainless steel, aluminium and aluminium alloys, copper, cobalt, lead, nickel, tin and zinc alloys. Non UKAS accreditation also covers plating solutions, air quality filters and foundry consumables. It works in tandem with the company’s in-house Mechanical Testing, Metallography, Weld Testing, Problem & Failure Investigation and Heat Treatment departments to provide an all-encompassing technical service, housed on one site.

Headed by Chief Chemist, John Whitaker, and his senior colleague Graham Woodward, each with almost 40 years’ industry experience, the department combines in-depth scientific knowledge and practical expertise. Submitted specimens range in size from a minute speck of material, to a test bar or finished component of virtually any size; the team then determines the appropriate testing technique, according to material type, sample size, required turnaround time and complexity of analysis.

Inductively Coupled Plasma spectroscopy is a very sensitive technique for identification and quantification of elements in a test piece. It is an ideal tool for major and trace detection of a wide range of elements in solution, in which a dissolved sample is injected into argon gas plasma, and it enables analysis down to parts per million detection limits, across a wide range of metals and alloys. The technique can also be used for measuring impurity levels in plating solutions and galvanising systems.

Atomic Absorption spectroscopy is a highly sensitive analytical technique that can measure down to parts per million. It relies on the atomic absorption process for determining the concentration of elements of interest, by measuring the amount of light absorbed, and is particularly suitable for bespoke analysis applications.

When dealing with solid pieces of metal down to 15mm in diameter, the Glow Discharge spectrometer is often the instrument of choice, a typical application being the analysis of foundry discs. It enables rapid elemental determination in most ferrous materials and is an excellent technique for many routine applications. The characteristic ‘sputter’ pattern of glow discharge instrumentation ensures uniform material removal from the sample surface.

The Chemical Analysis team accepts commissions from anywhere in the world, providing samples can be delivered safely, and is able to analyse virtually any metallic or metal-related material. With today’s engineers working to ever-tighter technical specifications and the quality control of manufactured and bought-in parts always high on the agenda, the department’s services are in growing demand.

Putting a test case for integrity management!

Widely-publicised catastrophic failures of forged materials in deepwater applications have called into question the structural integrity of such products and focused industry attention on the need for carefully-managed ‘integrity management’ of key components. Errors in material selection at the design stage, the use of incorrect heat treatment techniques and inconsistent mechanical testing regimes, often involving test pieces not taken from the actual components, can lead to product failures during operation, typically resulting in significant environmental, safety and financial costs.

With suppliers to the oil & gas and marine industries particularly appreciating the need for integrity management of deep sea components to prevent expensive failures or prolonged shutdowns, Keighley Laboratories is experiencing an upturn in demand for first article inspection of pre-production components, to ensure meeting operators’ engineering specifications. It is a preventative measure that the company believes could be adopted more widely, especially with the life expectancy of products extending from ten years to 25 years or more, often in extremely harsh and corrosive environments.

“Product failures bring problems that engineering companies simply don’t need, wasting time, money and damaging their commercial reputations, when customers are inconvenienced,” says Leonard Stott, Customer Support Manager for Keighley Labs’ Technical Services division. “More than ever there is a definite requirement for proven product reliability and fitness-for-purpose, as well as a need for consistent mechanical and corrosion properties that can only be achieved by applying the correct processing and heat treatment techniques. Also, product testing procedures need to be accurate, not least the correct positioning and orientation of test sample pieces, to ensure optimum and consistent test values.
“It would be costly for suppliers to set up the necessary in-house procedures to ensure critical mistakes don’t happen, so it is worthwhile sub-contracting the metallurgical testing of components to independent experts like ourselves. We are specialists in the analysis, testing and heat treatment of metals, holding many leading quality accreditations relevant to various industry sectors, and we have the in-depth metallurgical knowledge and experience for the assessment of potential failures and the development of risk mitigation strategies.”

It was the catastrophic failure of a mooring shackle in the Gulf of Mexico and a second incident involving two sockets in another mooring system, which highlighted faults in the original heat treatment process as a likely cause. A subsequent report by the US Department of the Interior’s Minerals Management Service (MMS) concluded that defective heat treatment during component processing resulted in a metal unable to meet Charpy impact test requirements for material toughness and that testing parameters were either not followed or not adequate to ensure specifications were met.

The MMS recommended that operators should revise their specifications to make sure that testing and manufacturing produces a satisfactory product, which will meet future usage demands. It also commented that operators should review their requirements for both destructive and non-destructive testing of critical elements, as well as ensuring that test coupons, or pieces, are properly representative.

Indeed, it was later found that the test pieces were not samples taken from the actual product and subsequent research indicated the importance of sample positioning in achieving representative and consistent toughness values. Thus, while energy absorption in a longitudinal orientation achieved a satisfactory 70-80 joules, the same test in the transverse direction recorded a disastrously low 4 joules. It was also easier for a smaller test piece of 2” cross-section to pass the impact test, rather than a larger, more representative section.

Through a wealth of metal testing and heat treatment experience, developed over a market history dating back more than 90 years, Keighley Laboratories is perfectly placed to offer independent metallurgical testing, on a sub-contract basis. Its long-established Test House boasts a full array of physical and mechanical testing resources, including room and sub-zero temperature assessment down to -196°C, Charpy impact test and sample preparation provisions, all the main hardness and micro-hardness testing methods, and specialist equipment for tensile and compression loading and determining other key mechanical properties. Accelerated salt spray techniques, humidity chambers, solvent/chemical resistance and other corrosion-related testing are also among its specialised facilities.

A spacious new optical suite houses advanced metallurgical microscopes complete with image capture software, a fully-equipped CNC machine shop, a highly-respected chemical analysis department and a dedicated team of NDT inspectors qualified to PCN Level 2/3, further extending Keighley Labs’ in-house technical resources, establishing it as one of the best-resourced independent metallurgical testing services in the country. Added to which is its undoubted expertise in the heat treatment of metals, including expert consultancy on thermal and quenching processes and the selection of suitable materials at the design stage. The fact that all of these interrelated metallurgical capabilities are available to customers on a single site only strengthens Keighley Labs’ credentials for metallurgical testing of critical components and advising on product quality issues.

Lab accreditation achieved

The Technical Services division of Keighley Laboratories has achieved world-class Nadcap accreditation for a Materials Testing Laboratory (MTL), a status recognised by the majority of global aerospace primes as a mark of quality assurance excellence. The West Yorkshire Company also gained coveted Merit grade, which rewards superior performance in Nadcap audits and reduces subsequent audit frequency. Accreditation has also prompted affirmation and prolongation of its Airbus approval, the aircraft manufacturer having adopted the Nadcap programme for its global supply chain.

 Keighley Labs' MD Debbie Mellor, Tim Clegg, Peter Hanson and Matthew Mellor

As one of the few Nadcap-accredited MTL facilities in the UK, Keighley Labs has been successfully assessed for the evaluation of aerospace welds, tensile, impact and bend testing, metallographic and micro indentation hardness procedures, and specimen preparation and machining. Combined with UKAS accredited testing and certification to many international standards and Civil Aviation Authority approval of in-house weld specimen supervisors, this confirms the company as a centre of excellence for weld testing, at a time when there is a Europe-wide shortage of the necessary expertise.

“Achieving Nadcap accreditation is not easy; it is one of the ways in which the aerospace industry identifies those who excel in superior special processes. Companies such as Keighley Laboratories go above and beyond achieving Nadcap accreditation, to obtain Merit status, and they should be justifiably proud of that,” says Joe Pinto, Executive Vice President and Chief Operating Officer at the Performance Review Institute, which administers the Nadcap programme. “We are determined to support continual improvement in the aerospace industry, by helping companies such as Keighley Labs become even more successful.”

Established in 1990 by key aerospace industry and US government representatives, Nadcap represents a concerted, cooperative effort to improve quality, while reducing costs, throughout the global aerospace and defence sectors. It defines a standardised approach to quality assurance and establishes requirements for accreditation, improving performance throughout the supply chain, utilising expert auditors to ensure familiarity with special processes and conducting technically superior in-depth quality audits. With most aerospace prime contractors and secondary tier suppliers now adhering to Nadcap, accreditation is vital for securing subcontracting opportunities in this sector, as well as in quality-minded markets like nuclear, marine, defence and rail, with more than half of accredited companies reporting an upturn in sales and new business.

“This is an important breakthrough for the company, since it raises our profile and reputation within the aerospace industry and enables us to obtain greater recognition for our expertise in weld and materials testing,” says Keighley Labs’ MD, Debbie Mellor. “It helps us to retain existing customers within the Northwest Aerospace Alliance and beyond, establishes our technical credentials for fresh market opportunities in other industries and paves the way for further export business in weld testing and other special processes.”

The Keighley Labs’ Nadcap application, which was supported by numerous key aerospace customers and Airbus itself, involved Divisional Technical Services Director, Matthew Mellor, Senior Metallurgist, Peter Hanson, and Quality Manager, Tim Clegg, in a thoroughly intensive programme.

Although modern composites are increasingly used in aviation, metal is still the most prevalent aircraft construction material, including but not limited to steel, aluminium, stainless steel, nickel and titanium alloys. The company’s in-depth weld assessment and inspection expertise, across all metallic materials and current manual and automatic welding methods, will ensure that welded joints comply with the highest aerospace and equivalent specifications.

The company already has quite a number of aviation primes and tier 1, 2 and 3 supply companies amongst its customer base, as well as overseas defence and aerospace suppliers, and is confident of using Nadcap Merit status to leverage extra domestic and export business.

New heat treatment facility

Construction work is now underway on Keighley Laboratories’ new heat treatment processes building, at its West Yorkshire headquarters (GB). After a detailed topographical survey, site clearance and levelling, the steelwork is now being erected and the building is due for completion in February, with the mechanical and electrical (M&E) services scheduled for completion by next summer.

Representing a total capital investment in excess of £1 million, the purpose-built unit will house furnaces, controls and ancillary equipment for new and complimentary processes, augmenting Keighley Labs’ existing array of heat treatment services.

MD Debbie Mellor in site excavator

“We are effectively in the first stage of moving forward again as a company, by making a sizeable investment in new facilities and positioning ourselves with some of the best resources in the industry,” says Keighley Labs MD, Debbie Mellor, who took time out from her busy schedule to be pictured at the controls of a site excavator. “In this new building, we shall have modern furnace equipment and the most sophisticated process controls, enabling us to regulate precisely the parameters to suit clients’ exact specifications. We shall offer a service that is second-to-none, from a single site at the heart of the engineering and aviation supply industry.”

Adjacent to the existing induction hardening department and now sharing a common despatch yard, the new 5,000sq ft building is being clad in the same grey-blue coated steel wall and roofing sheets. Before construction could commence, 2H Architecture, supervised the initial enabling contract, which involved demolishing the previous maintenance building.

“Given the heat output from the furnaces, we have taken these thermal installation requirements into account when designing the building envelope,” says 2H co-founder Brenden Harrison. “We are working to current building regulations for walls, flooring and roof plus 20%, to ensure optimum energy efficiency for the new building and reduce running costs.”

The interior will accommodate the heat treatment furnaces, programmable controllers, degreasing equipment and post-process wash units, with a main side entrance to suit the proposed workflow.

Keighley Labs anticipates that the markets that will be served by these new processes will include products such as gears, crankshafts, valve parts, camshafts, cylinders, railway braking systems, pump components and pipeline fittings. Full-time positions will be created by the new heat treatment facility, together with several apprenticeship opportunities, adding to an existing headcount of 65 personnel.

The site architects are 2H Architecture of Leeds, the main contractor is Triton Construction of Liversedge and the M&E services are being provided by Dualtec of Keighley.

Test & inspection service ensures welds are fit for purpose

Usually regarded as the most economical way of joining two or more metal components, in terms of fabrication costs and materials usage, welding technology is central to many engineering and manufacturing processes, from producing wings and fuselages in the aerospace industry and platforms and pipelines in the energy and petrochemicals sector, to automotive and rail components, white goods and metal furniture. Since these welded joints are subject to various loads and fatigue during their service life, possibly giving rise to safety and quality issues, it is vital that rigorous testing and inspection procedures are applied, to examine the structure of completed welds and their conformation to specification, as well as determining the skill levels of the welding operators.

Keighley Laboratories offers a comprehensive weld testing and inspection service, including welding procedure consultancy and approval, welder qualification tests, on-site weld investigation and, through its newly-upgraded Test House, a complete range of destructive, non-destructive and metallography testing facilities.

Under the direction of Divisional Technical Services Director, Matthew Mellor, the weld test and inspection team’s resources are broadly divided between the specialist aerospace field, led by Peter Hanson, and general commercial welding, headed up by Jeremy Duignan, both of whom are fully qualified metallurgists. Unusually, Matthew, Peter and Technical Director, Keith Blower, are also approved by the Civil Aviation Authority as Weld Specimen Supervisors, able to witness and verify critical aircraft-related welding on the authority’s behalf and invigilate at customer sites.

Keighley Labs is UKAS accredited for weldment testing and certification across a growing list of professional specifications, including relevant commercial BS EN ISO and ASTM standards and aerospace primes like BAE, Rolls Royce, Westland Helicopters, Airbus, Bombardier and the CAA, with the final assessment process now underway for NADCAP approval.

The team is familiar with testing weld coupons only millimetres thick in titanium, aluminium, nickel and cobalt alloys and other exotic metals for aerospace fabricators, as well as carbon steel and stainless steel test plates several inches thick for commercial welders and manufacturers. It covers all forms of welded joint, including butt or groove welds, fillets, lap, edge and tee joints, corners and cruciform, both plate-to-plate and tube-to-tube in similar or dissimilar materials, which are produced using all manual and automated welding methods, from stick and oxy-acetylene techniques, to TIG, MIG, MAG and plasma arc, even brazing and soldering.

Keighley Labs employs a complete array of test and inspection procedures to qualify welding procedures, welding operators and welding processes, by examining completed welds to establish their quality, integrity and compliance with specifications. Non-destructive testing techniques extend from visual inspection to check for surface defects and weld sizes, through to magnetic particle, liquid penetrant and ultrasonic examinations for detecting surface and near-surface discontinuities invisible to the naked eye, locating weld leaks and any internal flaws, in addition to meeting specific codes and specifications. Radiographic inspection for determining the internal soundness of welds is also provided on a sub-contract basis.

Weld coupons are also examined for soundness, strength and toughness using a range of mechanical testing equipment in Keighley Labs’ on-site Test House, which includes a dedicated CNC machine for producing weld test plates from customer-submitted samples. Options here include Brinell, Rockwell, Vickers and Knoop hardness testing, for providing information about metallurgical changes caused by welding, weld bending for evaluating the ductility and soundness of welded joints, Charpy and Izod impact testing for measuring resistance to mechanical shock, and digital equipment for fatigue life testing.

In its newly-enlarged Optical Suite, Keighley Labs offers metallographic inspection of sections of welded joints, at macro levels up to 50x magnification and micro examinations up to 1000x, employing powerful stereo microscopes. Metallurgy is used to check the extent of the heat affected zone and any weld defects such as cracks, pores, swivels and lack of fusion. Meticulous surface preparation of samples is essential for revealing details of the microstructure and the suite boasts semi-automated precision cutting, grinding and polishing equipment.

With customers as far afield as South Africa and the Mediterranean, as well as closer to hand amongst the North West Aerospace Alliance, of which it is a member, Keighley Labs enjoys strong demand for its weld test and inspection services, with a track record of repeat business.

“We have a good reputation within the aerospace industry and amongst commercial fabricators and, given the increasing need to comply with welding procedures and employ skilled welding operators, it is an expert service that many customers and their clients value,” says Keighley Labs’ Peter Hanson. “Being independent, we have no vested interest in any particular welded joint, we’re just concerned with whether it passes or fails. If it fails, we can identify precisely why it did so and offer remedial advice for meeting the required specification.”

“A good looking joint was often considered a reliable indicator of a high quality weld, but surface appearance alone does not guarantee good workmanship, internal integrity and compliance with welding procedures,” he adds. “Nowadays, you need access to non-destructive mechanical and metallurgical examination techniques to judge whether a weld is fit for purpose and achieves the necessary acceptance criteria. And that’s what we do.”

Portable NDT instruments

Expanding its non-destructive testing (NDT) techniques and complementing its existing array of advanced instruments, Keighley Laboratories has invested in a portable conductivity meter, which measures the electrical conductivity of non-ferrous metals employing the eddy current method, and a pocket instrument for convenient and fast coating thickness measurement, using magnetic induction and eddy current technologies. Both measuring techniques are applicable to the aerospace, automotive, petrochemical, engineering, heat treatment and other fields and complement the specialist NDT services the company already offers to industry clients.

Through its Technical Services division, Keighley Labs covers many of the mainstream NDT methods, notably magnetic particle crack detection, dye penetrant testing, ultrasonic flaw detection, magnetic permeability, positive material identification, residual magnetism and ferrite determination, as well as radiography on a sub-contract basis. Its highly skilled and experienced NDT technicians are qualified to at least PCN Level 2 in several disciplines and are able to define and implement tests that detect and analyse material flaws that might otherwise give rise to critical component failure or quality control issues, either working in the laboratory or at the customer site. Many methods are covered by the company’s UKAS accreditation, for testing at customer premises.

The electrical conductivity of a metal depends on various factors, such as chemical composition, the stress state of its microstructure and mechanical properties, so can be used for sorting metals and checking proper heat treatment, as well as identifying how well a metal conducts electrical current for anodising and other processes. The company’s new instrument will measure the electrical conductivity of non-ferrous metals, such as aluminium alloys, copper and even stainless steels, using the eddy current method in accordance with DIN EN 2004-1 and ASTM E 1004 standards and determining conductivity of materials under paint or synthetic coatings up to 500µm thick.

Employed both in-house and for external clients, it will enable Keighley Labs to monitor the hardness and strength of heat treated materials like aluminium alloys and inspect for any heat damage. The same instrument will also be used for scrap metal sorting at customer sites, determining the purity of non-ferrous metals and verifying the homogeneity of alloys, as well as for the inspection of finished goods. It will even detect counterfeit coins.

The other NDT technique, for measuring the precise thickness of such applied coatings as paint, powder coatings, plastics and plated finishes, is equally important for ensuring compliance with thickness specifications, preventing defective coatings and subsequent corrosion, maintaining product quality and controlling production costs. The company’s newly-acquired pocket instrument will provide for non-destructive measurement of the total thickness of coatings up to 2000µm thick, applied to ferrous and non-ferrous materials. It will automatically recognise the underlying material, such as steel or aluminium, and select the appropriate one of two test methods, which are eddy current and magnetic induction in accordance with ISO 2178, ASTM D7091 and ISO 2300 standards.

With an on-board memory for up to 1000 readings, it will allow Keighley Labs technicians to measure paint, lacquer or plastic coatings on a whole range of metals, anodised coatings on aluminium components, electro-plated zinc, chromium and copper finishes, and sputtered thin-film deposition.

As with all advanced NDT techniques, a considerable degree of operator skill and experience is required to apply these test methods properly, obtain the maximum amount of information, then interpret the results and provide feedback for the client. With the newly-acquired instruments, this process will be aided by the capacity to download results directly from the portable devices to the NDT department’s computers, for error-free data transfer and subsequent analysis and report generation.

Divisional directors appointed

Keighley Laboratories has appointed three of its long-serving managers to Divisional Directors, in recognition of their contribution to past performance and their key roles in future growth plans. Together clocking up almost a hundred year’s work experience with the West Yorkshire firm, Michael Emmott becomes Divisional Commercial Director for the Heat Treatment Division, Matthew Mellor is now Divisional Technical Director responsible for the Technical Services Division, including the test house, machine shop and chemical laboratory, while David Wright has been named Divisional Production Director for the Heat Treatment Division.

“We are entering an important new phase for the company, especially with the opening of our latest production facility this year, and these promotions were designed to help restructure the senior management team, to lead the company forward,” says MD Debbie Mellor. “By assuming greater responsibility, each new Divisional Director will have ownership of his respective area and the capacity to implement strategic changes, instigate further process improvements and ensure our continued market progress.”

From left: David Wright, Michael Emmott and Matthew Mellor

Michael Emmott, Divisional Commercial Director
Michael joined Keighley Labs in 1969 as a trainee heat treatment inspector and progressed to induction hardening, before a 10-year stint as Night Shift Inspector, then Supervisor. He later transferred to the company’s commercial activities, becoming Commercial Manager for the heat treatment business area and travelling extensively both at home and overseas.

In his new role, Michael will be fully responsible for divisional sales and marketing, managing the company’s national and international customer base and targeting fresh business opportunities arising from the new production facility and other technical initiatives.

A qualified mechanical engineer, he gained a BSc in Maths & Computing from the Open University and also has a teaching diploma, allowing him to lecture at colleges of further education. Michael is married with three daughters.

Matthew Mellor, Divisional Technical Services Director
Matthew joined Keighley Labs in 1990 from Bingley Grammar School, as a trainee metallurgical technician. He then progressed by stages from Technician, to Senior Technician, then Test House Supervisor, before assuming his previous role of Test House Manager.

In his new position, he will undertake planning, coordination and management control of the company’s test house, machine shop and chemical analysis departments, monitoring personnel performance and ensuring adherence to quality standards, at the same time looking to improve overall efficiency and optimising costs. He will also maintain and expand the company’s technical accreditations, adding to an already extensive list that includes UKAS, British Aerospace, Bombardier, Rolls Royce and Airbus, as well as furthering the process of securing NADCAP approval.

A qualified metallurgist and Civil Aviation Authority (CAA) Approved Supervisor, Matthew is married and has one daughter. He is a keen table tennis player and competes regularly in the local league.

David Wright, Divisional Production Director
David joined Keighley Laboratories in 1978 as a general operative, subsequently gaining hands-on experience of most roles in the heat treatment workshop. He was later promoted to Supervisor, then Production Manager, before being elevated to Divisional Director.

In his new post, David will manage a team of up to 40 staff and be in overall charge of the company’s production process and ancillary operations. He will oversee the integration of the new production department, toward the end of this year, and ensure that the total heat treatment function conforms with expected quality standards and turnaround times. He will also play a key role in evaluating the application of advanced techniques to existing heat treatment processes.

Having gained a Diploma in Management through a 2-year distance learning programme at Newcastle College, he later added a Diploma in Business Coaching, gaining an insight into team and organisational dynamics.

Quality manager hits the ground running!

We have had a number of new appointments announced in the past few days.

pic: woodentops.org

Keighley Laboratories has appointed Tim Clegg as its Quality Manager, replacing the long-term incumbent Peter Warriner, who is retiring shortly. Tim originally served his apprenticeship with the company, during which he gained a Metallurgical Technician diploma from Bradford College, before working for a nearby production engineering firm for twenty years. He returned to Keighley Labs last year as its Health & Safety Manager and a senior quality management trainee. He will now perform a dual role, steering through the company’s comprehensive quality accreditation programme and maintaining awareness of correct H&S procedures throughout the organisation, which already has a good safety record.

“We are delighted that Tim is taking on this critical quality management role, because he has extensive metallurgical experience and is well respected within the company,” says Keighley Labs MD, Debbie Mellor. “This year is particularly important since we are looking to attain Airbus and NADCAP accreditations, recognised as the most technically demanding across industry, which will open up fresh market avenues for us and reassure our existing customers that we maintain the ultimate quality standards.”

A youthful-looking 54 year old, Tim Clegg is a highly regarded fell and road runner and has been a member of Keighley & Craven AC for around thirty years. In April, he will compete in the demanding Yorkshire Three Peaks fell race for the tenth consecutive year and, as part of his training, he runs regularly to work, from his home in Shann Park, Keighley. He is married with three children.

Having previously worked as a Furnace Controller with Anderton International of Bingley, maintaining a computerised load list of heat treatment furnaces, Tim later became a Laboratory Technician when the firm merged with Ellison Circlips of Keighley, subsequently rising to Senior Quality Engineer, with metallurgical and final inspection responsibilities. In his new role as Keighley Labs Quality Manager, he will build on the company’s well-established quality management system, looking for opportunities for enhancement and meeting ever-changing customer requirements.

In addition to membership of many distinguished trade associations, such as the North West Aerospace Alliance, Engineering Industries Association and Contract Heat Treatment Association, Keighley Labs holds a continually growing portfolio of quality accreditations. These include the essential UKAS Testing ISO/IEC 17025 standard, BSI Heat Treatment quality management system BS EN ISO 9100:2009 and its associated aerospace standard AS9100 Revision C, and BS EN ISO 9001:2008 quality management accreditation. Among Tim Clegg’s duties will be maintaining a documented quality assurance programme, supervising the work of quality control staff, providing relevant training and adding to the company’s extensive UKAS schedule of accreditation.

Automatic hardness testing facility

Maintaining its policy of continuous investment in technology and facilities, Keighley Laboratories has added a Zwick Roell ZHV-10 automatic micro and macro hardness tester to its Test House resources. Featuring fully automatic Vickers indentation measurement and dedicated hardness testing software, the new equipment will bring about measurable improvements in accuracy, repeatability and productivity, to the benefit of the company’s internal Heat Treatment division and clients of its Technical Services department. Used for the precise measurement of surface hardness and case depth of metallic materials, with test loads between 100g and 10Kg, it will introduce considerable time savings over previously manual routines, freeing up highly skilled operators for other analytical duties.

The new equipment was supplied by Indentec, part of Zwick Roell AG and a worldwide centre of excellence for hardness testing machines, which has a business relationship with Keighley Labs that dates back many years. A UKAS accredited calibration laboratory, Indentec has been additionally contracted to service and recalibrate this and other hardness testing equipment on a long term basis, which will be carried out on site by trained engineers to ISO 6508-2 and ASTM E384 standards.

Such is the sizeable footprint of the new hardness tester, Keighley Labs also took the opportunity to enlarge its existing Test House microscope room, creating a spacious new optical suite. This also houses the advanced zoom stereo metallurgical microscope acquired previously and allows for the installation of further state-of-the-art equipment.

Part of Keighley Labs’ comprehensive mechanical testing and metallography services, the hardness of a material is determined by its resistance to indentation by a hardened ball or diamond indenter, then measuring the size of the permanent impression produced. With loads, pressures and temperatures constantly increasing in modern machinery, metallic parts are subject to increasingly arduous operating conditions and hardness testing is often the best way of establishing that components will survive such stresses, becoming a critical part of the quality control process. Keighley Labs employs this physical testing method as quality assurance for its in-house Heat Treatment division, handling up to a dozen test samples daily, as well as undertaking case depth and surface hardness evaluation of materials and components for external clients.

Vickers testing, using a pyramid-shaped diamond indenter, is suitable for all types of materials and surface treatments and Keighley Labs’ new Zwick Roell ZHV-10 machine is equipped for micro and macro Vickers testing to ISO 6507, although it can be fitted with an alternative Knoop indenter. It features a built-in measuring microscope with four objective lenses, a motorised turret with 1.3 megapixel USB camera, an automatic motorised XY table with 150mm x 50mm travel, for precise positioning of samples, with automatic focus providing an additional motorised Z axis for bringing the test surface into sharp resolution without operator involvement. It also includes a high definition 24” LCD monitor, a microprocessor running Windows XP, flatbed scanner and Indentec ZHµ HD automatic indentation software, with sample scanning facility and a report generator for outputting data to spreadsheet programs, enabling further statistical analysis.

Employing this configuration, Keighley Labs’ technicians can either view and measure test impressions manually, by focusing with the joystick and clicking on indentations with the mouse, or allow the machine itself to intelligently follow predefined patterns, indent the sample, then measure and generate test results, all entirely automatically. They can also set up templates of indentation points, for performing hardness tests on routine samples, and program straight line and transverse patterns for automating case hardness routines and testing welded seams.

Apart from freeing up technicians for other tasks, this ‘click and walk away’ functionality ensures precise sample positioning and imaging, enhanced accuracy, an extremely high level of repeatability and overall increased productivity, reducing standard testing procedures from more than an hour manually, to less than twenty minutes automatically. It also eliminates operator-related errors caused by eye strain, fatigue and inevitable inconsistencies, which can be a common problem in microhardness testing especially.

“The time savings made possible by this automatic hardness tester will enable us to offer faster turnaround times and deliver even more accurate, repeatable and reproducible data,” says Keighley Labs’ Test House Manager, Matthew Mellor. “We chose Indentec because the company has an excellent reputation, with its own service and calibration engineers, and its equipment offers the highest image resolution on the market.”

Aircraft welding testing

Three Keighley Laboratories staff approved As CAA Weld Specimen Supervisors

Keith Blower

Mathew Mellor

Peter Hanson

The Metallurgical & Laboratory Services division of Keighley Laboratories has achieved the unusual distinction of having three of its senior employees approved by the British Civil Aviation Authority as Weld Specimen Supervisors. Keith Blower, Matthew Mellor and Peter Hanson have all been officially recognised as approved signatories for the purpose of witnessing and certifying aircraft-related welding of test specimens, as defined in the authoritative BCAR (British Civil Airworthiness Requirements) Chapter A8-10 on the approval of welders.

The procedures outlined in Chapter A8-10 are applicable to those who weld metallic parts that are essential to the airworthiness of an aircraft, where the achievement of a sound metal-to-metal joint depends largely on the competency of the operator. For welders not employed by a CAA approved organisation, test samples must be prepared under the supervision of a person authorised as a signatory, then submitted to a CAA approved test house for examination. Keighley Labs' newly-approved signatories can now undertake weld invigilations at the customer's premises, then the samples can be examined and certificated at its CAA recognised test house, providing a critical one-stop service.

The company's three Weld Specimen Supervisors are highly qualified specialists with many years' combined experience. 

Keith Blower of Steeton is the firm's Technical Director, with specific responsibility for the Problem & Failure Investigation department. 

Matthew Mellor of Oakworth is the Test House Manager, who also runs the firm's high tech metallurgical laboratory. 

While Peter Hanson of Denholme is the company's Senior Investigation Metallurgist, who specialises in failure and fracture investigations. All three are also linked to Keighley Labs' weld procedures consultancy, which provides welder qualification approvals to European, US and international standards.

"This important CAA approval came about following a number of enquiries from customers, as to whether we could witness weld testing on behalf of the CAA," says Matthew Mellor. "We spoke to the authority when they next visited our test house and the region's Assistant Surveyor subsequently issued us with a letter of approval. It's quite a distinctive accolade, since I don't know of any other technical laboratory that has the same status."

This latest accreditation is of particular interest to manufacturers who carry out welding on aircraft or weld parts for aircraft, that don't have CAA approval; in addition to earlier customer enquiries, the company already has interest from as far afield as Ireland. A member of the Northwest Aerospace Alliance with a long history of working with aerospace primes and their suppliers. Keighley Labs' Metallurgical & Laboratory Services division is also UKAS accredited and operates to international aerospace standards.

NDT resources

Keighley Laboratories adds to non-destructive testing resources

Non-destructive testing (NDT) is a highly valued quality assurance and analytical technique that helps safeguard against the potential failure of engineering material, components, fastenings and structures. Since it enables in-depth evaluation of a material without causing damage, NDT often provides the final QA stage before a new product enters service, while in-service NDT can be the last line of defence against component failure in the field.

As part of its broad range of advanced metallurgical solutions, Keighley Laboratories offers a specialised NDT service for clients in the aerospace, automotive, petrochemical, nuclear, defence, mechanical engineering, construction, civil engineering and allied industries, covering both laboratory and site inspection. The company continually invests in staff training and new technology to expand its capabilities, recently adding to its NDT resources with a new digital flaw detector for more demanding ultrasonic testing, a magnetic permeability meter for critical aerospace and nuclear energy applications, and a hand-held ferrite content meter for testing weld seams and piping materials in the oil, gas and petrochemical industries.

Their NDT facility covers the two most common methods of surface crack and flaw detection, Liquid Penetrant Testing and Magnetic Particle Testing, and the volumetric inspection technique, Ultrasonic Flaw Detection, as well as providing Radiographic Testing services on a sub-contracted basis. Non-destructive testing and inspection procedures are highly operator-dependent, relying upon the skills and experience of NDT technicians to obtain and evaluate results, and all members of the Keighley Labs team are certificated to a minimum of PCN Level 2, an internationally recognised symbol of competence. Indeed, Senior NDT Engineer, Roger Wheatley, is qualified to PCN Level 3 and able to develop NDT procedures, write instructions, audit techniques and both train and examine Level 1 and 2 candidates, making him a valued asset for both the company and its customers.

Roger Wheatley

“We like to think of ourselves as the best, with a high degree of technical skill and experience, able to handle the most critical components,” says Roger. “Although most of our work is carried out in the lab, around 20 per cent of projects are on site, checking fixtures that cannot be moved like motorway bridges, presses, silos, boilers, offshore rigs or miles of installed pipelines in paper mills and petrochemical plants. At the other end of the scale we also handle private work for owners of vintage vehicles, checking the integrity of steering racks and drive trains in readiness for classic car shows.”

For the detection of surface breaking flaws on ferrous and non-ferrous materials, such as casting and forging defects, weld cracks, leaks in new components and fatigue cracking on in-service components, Keighley Labs provides Liquid Penetrant Testing with either colour contrast or fluorescent techniques, working to national and international standards including BS EN 571:1997. LP testing can be undertaken either in the firm’s laboratory or at the customer site.

Magnetic Particle Inspection is conducted on ferro-magnetic materials, by inducing a magnetic field into the test piece, and is ideal for detecting cracks, porosity, seams and other surface breaking, as well as sub-surface discontinuities down to 2mm. Imperfections are revealed using fluorescent or non-fluorescent media; on-site testing is carried out using permanent magnets or portable electro-magnetic yokes where a suitable power source is available. Suitable for welds, castings, forgings and machined parts, including engine, suspension and braking components, testing is carried out by Keighley Labs to BS EN ISO 9934-1 and BAE RO5-6103 standards.

For identifying imperfections within a test piece or any changes in material properties, Ultrasonic Flaw Detection reveals volumetric discontinuation, utilising sound waves introduced into the component from an ultrasonic source. Undertaken by digital and analogue machines, ultrasonic detection is able to penetrate up to 10m in steel and can detect laminations, lack of fusion and any corrosion, as well as carrying out thickness and depth checks. This technique is suitable for welds, wrought iron products and castings in magnetic and non-magnetic materials, including glass, ceramics and plastics, again with tests carried out either in-house or on-site.

To upgrade its ultrasonic testing facilities still further, Keighley Laboratories has invested around £8k in a new Sonatest Masterscan digital flow detector, which incorporates the latest developments in amplifier and pulsar technology to deliver higher levels of near-surface resolution and penetrating power. The NDT department has also added a digital magnetic permeability meter, for measurement of ferro-magnetic inclusions in feebly magnetic materials against relevant specifications, and a hand-held ferrite content meter, for analysing the ferrite content in austenitic and duplex steel; both are suitable for off-site or in-house applications and give Keighley Labs further distinctive methods of material inspection, in line with the latest customer requirements.

Keighley Labs technical services laboratory is accredited by UKAS, NADCAP, the UK Civil Aviation Authority, Rolls Royce, Bombardier Aerospace and British Aerospace, enabling it to carry out sub-contract testing of aircraft and associated companies, and it meets the accreditation standards of many other customer industries.

Independent chemical analysis

Currently celebrating its 90th anniversary Keighley Laboratories is putting the spotlight on its advanced Chemical Analysis facility, bringing it to the attention of an even wider spectrum of industry. Its team of analytical chemists has over 150 years’ combined experience, ensuring that samples are assessed by the most economical and efficient method, depending on the type of material, the size and form of specimen, and the degree of accuracy required. It is a level of service that has retained customers for 30 or 40 years and attracted business from across Britain and as far afield as Saudia Arabia.

Chemical analysis at the laboratory involves determining the elemental constituents of a wide range of materials, including cast iron, steel and stainless steel, aluminium, copper, nickel and titanium alloys, weld metals and non-metallic compounds like foundry sand. The laboratory employs state-of-the-art spectroscopy equipment, classical gravimetric and volumetric ‘wet’ methods, and qualitative depth profile analysis to check that submitted samples meet a required specification, for quality assurance purposes, as well as identifying any material coatings and metallurgical treatments.

In addition to analysing known samples from general engineering companies, foundries, the aerospace industry, galvanisers and platers, importers and the like, Keighley Laboratories also applies reverse engineering principles to unknown components. This enables parts of existing machinery to be identified and replicated where documentation is lost, for example, mixed stock to be reclassified when certification is missing, or corroded parts to be replaced with like-for-like material. Similar examinations also form part of the company’s Problem & Failure Investigation service, for forensic analysis of failed components, health & safety investigations and insurance claims.

“It is relatively unusual for an independent metallurgical services company to offer this level of experience and equipment,” says Chief Chemist, John Whittaker. “We offer a prompt turnaround and a highly personal service and, because we don’t manufacture anything ourselves, there are no confidentiality or conflict-of-interest issues.”

Specimens typically arrive by rail or carrier and range in size from a minute speck of material to a solid component or sample of virtually any size, with pricing dependent on the complexity of analysis and the quantity of material. When dealing with solid pieces of metal, the laboratory’s Glow Discharge Spectrometer is the instrument of choice, since it offers the quickest, most accurate bulk analysis of steel, stainless steel, nickel, aluminium and copper alloys, as well as quantitative depth profiling.

Where the sample size is limited or the format unsuitable, an Inductively Coupled Plasma Spectrometer is employed, which uses an argon plasma and enables low sample weights to be analysed down to parts per million detection limits. It is a very sensitive technique for identification and quantification of elements in a sample, although this ‘wet’ process does take a little longer.

For the precise measurement of residual and trace elements, the Flame Atomic Absorption Spectrometer is the preferred analytical tool, measuring down to parts per million in a sample; this method is also useful where no certified reference materials are available. In addition, classical chemical analysis techniques are used to augment spectrometry instruments, to provide a ‘control’ check for results and determine gravimetric, volumetric and photometric characteristics.

Results usually take the form of material certification, positive material identification or trace element analysis and are typically emailed to the client. Work is carried out to UKAS Metallurgical Laboratory Service accredited standards and conforms with relevant BS EN ISO specifications.
“Basically, if a sample can be delivered or posted to Keighley, we can accept commissions from anywhere in the world and analyse virtually any metal or metal-related material,” adds John Whittaker. “With manufacturers and suppliers working to ever tighter technical specifications and quality control high on the agenda in the engineering industry, it’s an independent service that is in growing demand.”