Robert Lancaster

Robert Lancaster
Swansea University | SWAN · Department of Materials Engineering

BEng PhD CEng PGCHE FHEA MIMMM

About

78
Publications
27,178
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
743
Citations
Citations since 2017
48 Research Items
632 Citations
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150
2017201820192020202120222023050100150

Publications

Publications (78)
Article
A new standard is currently being developed under the auspices of ECISS/TC 101 WG1 for the small punch testing technique for the estimation of both tensile and creep properties. Annex G of the new standard is covering the assessment and evaluation of small punch creep (SPC) data. The main challenge for estimating uniaxial creep properties from SPC...
Article
Full-text available
In recent years the use of Additive Manufacturing (AM) has become increasingly widespread with numerous industries now moving towards large scale manufacture of structurally integral components. The nature of AM offers the ability to manufacture more complex and optimised geometries, such as cooling channels and honeycomb structures, which would no...
Article
Full-text available
The nickel-based superalloy Haynes 282 is a promising candidate material among the existing batch of aerospace alloys for manufacture via laser powder bed fusion (LPBF). LPBF Haynes 282 has a strong preference for epitaxial grain growth in the (001) orientation, promoting inhomogeneous grain morphologies and anisotropic mechanical behaviour. In thi...
Article
Full-text available
A novel approach for down-selection of a repaired support structure design produced using Laser Blown Powder – Direct Energy Deposition (LBP-DED) and filled with interstitial Ni-Al powder (∼0.75 area fraction) in a turbine segment was investigated. Simulation of flattening and un-flattening of the segment with implications to degradation of the sup...
Article
The Small Punch (SP) and Shear Punch (ShP) tests are well established mechanical test approaches that have found application in several industrial sectors for material ranking and mechanical property estimation, particularly where more conventional approaches are inhibited. Despite the advantages that the two test methodologies have to offer, the m...
Article
Additive manufacturing (AM) processes are currently under consideration for marine based components, predominantly due to the numerous benefits that the techniques have to offer over more conventional manufacturing routes. However, there are multiple engineering challenges and questions associated with the introduction of AM based parts into safety...
Article
The suitability of determining the strain rate sensitivity (SRS) of the CoCrFeMnNi high-entropy alloy (HEA) by small punch (SP) testing has been assessed at displacement rates ranging from 0.2 to 2 mm∙min⁻¹. The stress was found to increase as the displacement rate was raised from 0.2 to 2 mm∙min⁻¹, whereas the plastic strain distributions were sim...
Article
Additive manufacturing (AM) is an advanced manufacturing technique whose uptake within the aerospace industry is being limited by the lack of understanding of the effects of surface finish on the fatigue properties of AM built components. It is known that the surface profile of as-built AM parts is significantly rougher than its traditionally manuf...
Article
This work compares the mechanical and corrosion properties of 316 L steel manufactured by Laser Powder Bed Fusion (LPBF) and post treated by Hot Isostatic Pressing (HIP) to wrought 316 L. HIP is often used by default on LPBF components to reduce porosity and obtain the best mechanical properties, however, if the HIP temperatures are too high, there...
Article
There is a clear economic benefit for the recycling of metallic powder during additive manufacturing (AM). Laser powder bed fusion (L‐PBF) is one such AM process and research has found that the properties of the powder feedstock can change when the powder is reused through mechanisms such as spatter generation and alterations in chemistry. Such cha...
Article
Duplex stainless steels (DSS) are a family of stainless steel alloys that benefit from the presence of two relatively equally proportioned phases, ferrite and austenite. The alloys are designed to have an enhanced resistance to corrosion and superior strength properties in comparison to more common stainless steel alloys such as 316 L. Design engin...
Article
Thermo-Mechanical Fatigue (TMF) is one of the most complex mechanical phenomena that couples creep, fatigue and oxidation. So far, developing simple empirical relationships like those that exist in isothermal equivalents have proven elusive. This work presents a study on the TMF behaviour of the aerospace nickel based superalloy RR1000 using TMF fa...
Article
Full-text available
To fully exploit the benefits of additive manufacturing (AM), an understanding of its processing, microstructural, and mechanical aspects, and their interdependent characteristics, is necessary. In certain instances, AM materials may be desired for applications where impact toughness is a key property, such as in gas turbine fan blades, where forei...
Article
The measurement of melt pool width has proven to be critical in the development of advanced control systems, defect detection algorithms and understanding the influence of parameter changes on build quality in additive manufacturing processes. Parametric studies are performed on new materials and builds to help identify optimal parameter settings f...
Article
Additive manufacturing (AM) processes are currently being investigated to determine their suitability for wider adoption in the aero engine industry where material consistency and structural integrity are essential. A key driver is the ability of AM to produce near net-shape components and complex geometries, reducing material wastage and tradition...
Article
Full-text available
Additive manufacturing processes have previously benefited from the introduction of melt pool dimensioning systems. These typically measure melt pool width by performing binary thresholds and highlighting edges using common edge detection algorithms. Melt pool monitoring systems have been successfully used to develop control systems and enhance pro...
Article
The current paper presents work on identification and evaluation of a range of factors influencing accuracy and comparability of data generated by three laboratories carrying out stress-controlled thermo-mechanical fatigue crack growth tests. It addresses crack length measurements, heating methods and temperature measurement techniques. It also pro...
Article
The polycrystalline nickel-base superalloy RR1000 is used as turbine rotor material in Rolls-Royce aero engines and has to withstand a wide variety of load and temperature changes during operation. In order to maximize the potential of the material and to improve component design, it is of great interest to understand, and subsequently be able to a...
Article
The current paper describes TMF crack growth behaviour in an advanced nickel-based superalloy. Changes in behaviour are examined which occur as a function of the phase angle between applied stress and temperature. The fractography of the failed specimens reveals changes from transgranular to intergranular growth between high and low phase angle tes...
Conference Paper
Full-text available
Additive manufacturing (AM) is a rapidly growing technology which is extending its influence into many industrial sectors such as aerospace, automotive and marine. Recently the nuclear sector has considered AM in the production of nuclear reactor components due to its possible advantages over conventional manufacturing routes. This includes conside...
Article
Additive manufacturing (AM) is a novel near net shape manufacturing technology that joins metallic powders layer upon layer in conjunction with 3D model data and as such offers tremendous potential to a wide range of industrial sectors given its ability to produce highly intricate components with very little material wastage. Subsequently, the aero...
Article
Full-text available
Additive Layer Manufacturing (ALM) is an innovative net shape manufacturing technology that offers the ability to produce highly intricate components not possible through traditional wrought and cast procedures. Consequently, the aerospace industry is becoming ever more attentive in exploiting such technology for the fabrication of nickel-based sup...
Article
Full-text available
Thermo-mechanical fatigue (TMF) is a complex damage mechanism that is considered to be one of the most dominant life limiting factors in hot-section components. Turbine blades and nozzle guide vanes are particularly susceptible to this form of material degradation, which result from the simultaneous cycling of mechanical and thermal loads. The real...
Article
Full-text available
Small scale mechanical test methods are now widely recognised as an established and quantifiable means of obtaining useful mechanical property information from limited material quantities. Much research has been gathered employing such approaches, but to date these methods have largely been restricted to characterising the creep, tensile and fractu...
Article
Full-text available
Thermo-mechanical fatigue data is critical for the generation of appropriate lifing methodologies for a range of in-service applications where non-isothermal conditions are prevalent. Recently the development of more standardised testing approaches through appropriate code of practice documents and international standards has proved crucial. In the...
Article
Full-text available
Nickel based superalloys have been utilised within numerous industrial sectors from power generation to chemical processing plants for over four decades as a result of their ability to retain mechanical properties at arduous temperatures alongside excellent oxidation and corrosion resistance. Within the aerospace industry, they have been primarily...
Article
Full-text available
Nickel-based superalloy C263 has been consolidated with Laser Powder Bed Fusion (LPBF) with two perpendicular build orientations and exposed to either of two heat treatment programmes. This study analyses the effects of build orientation and heat treatment on the resulting microstructures produced in LPBF C263 variants, evaluated against a cast equ...
Conference Paper
Full-text available
Miniaturised mechanical test approaches, specifically small punch testing, is now widely recognised as a means of obtaining useful mechanical properties, characterising the creep, tensile and fracture characteristics of numerous material systems from a range of industrial applications. Nevertheless, limited success has been found in replicating fat...
Conference Paper
Full-text available
Nickel based superalloys have been utilised within numerous industrial sectors from power generation to chemical processing plants for over four decades as a result of their ability to retain mechanical properties at arduous temperatures alongside excellent oxidation and corrosion resistance. Within the aerospace industry, they have been primarily...
Conference Paper
Full-text available
Metal Cold Spray (MCS) is currently under evaluation for its suitability for aerospace applications. However, before this technology can be implemented into the jet engine, the mechanical performance and structural integrity of this novel process must be fully understood. Limited data is currently available to determine key materials properties giv...
Article
Full-text available
Additive layer manufacturing (ALM) processes are becoming increasingly prevalent in the aerospace industry as design engineers look to profit from the numerous advantages that these advanced techniques can offer. However, given the safety critical nature and arduous operating conditions to which these components will be exposed to whilst in service...
Conference Paper
Life extension of aging nuclear power plant components requires knowledge of the properties of the service-exposed materials. For instance, in long term service the tensile and creep properties might decline and the ductile-to-brittle transition temperature (DBTT) might shift towards higher temperatures. Monitoring of structural components in nucle...
Article
Full-text available
The realisation of employing Additive Layer Manufacturing (ALM) technologies to produce components in the aerospace industry is significantly increasing. This can be attributed to their ability to offer the near-net shape fabrication of fully dense components with a high potential for geometrical optimisation, all of which contribute to subsequent...
Article
Full-text available
Miniaturised mechanical test approaches are now widely recognised as an established means of obtaining useful mechanical property information from limited material quantities. To date these methods have largely been adopted to characterise the creep, tensile and fracture characteristics of numerous material systems from a range of industrial applic...
Article
Full-text available
Direct Laser Deposition (DLD) is a modern Additive Layer Manufacturing (ALM) technology that offers the possibility of lean manufacture and the ability to produce near-net shape components with complex geometries. Anisotropic microstructures are typically produced due to thermal cycles that occur during the layer by layer process, resulting in epit...
Article
Full-text available
Additive Layer Manufacturing (ALM) technologies, such as Powder Bed Direct Laser Deposition (PB-DLD), have gained increasing popularity within the aerospace industry due to the advantages they hold over conventional processing routes. Among the advantages are the ability to produce more sophisticated cross-sectional geometries, a decrease in produc...
Article
Full-text available
Small punch (SP) tensile testing provides several advantages over conventional test techniques for mechanical property characterisation of components produced using novel manufacturing processes. Additive layer manufacturing (ALM) is becoming more widespread, particularly in high value manufacturing sectors such as the gas turbine industry as it al...
Article
Full-text available
Thermo-mechanical fatigue (TMF) tests including 0°, 90°, -90°, 45° -135° and -180°, phasing (φ) between mechanical loading and temperature were undertaken on a polycrystalline nickel-based superalloy, RR1000. Mechanical loading was employed through strain control whilst 300-700 °C and 300-750°C thermal cycles were achieved with induction heating an...
Article
Full-text available
The small punch (SP) test is a widely accepted methodology for obtaining mechanical property information from limited material quantities. Much research has presented the creep, tensile and fracture responses of numerous materials gathered from small-scale testing approaches. This is of particular interest for alloy down selection of next-generatio...
Article
Full-text available
This paper, invited for presentation at the 33rd Meeting of the Spanish Group on Fracture and Structural Integrity, March 2016 in San Sebastian, Spain, reviews the recent work carried out in the authors’ laboratory, addressing the elucidation of tensile and creep characteristics of materials for aero engine components. Two specific applications of...
Article
Full-text available
Advanced manufacturing encompasses the wide range of processes that consist of "3D printing" of metallic materials. One such method is Electron Beam Melting (EBM), a modern build technology that offers significant potential for lean manufacture and a capability to produce fully dense near-net shaped components. However, the manufacture of intricate...
Chapter
The use of additive layer manufacturing (ALM) processes such as electron beam melting (EBM) is becoming increasingly prevalent in the aerospace industry. The safety critical nature, coupled with the arduous operating conditions to which these additive manufactured components will be exposed mean that it is crucial that the me chanical properties of...
Chapter
Reduction of the buy-to fly ratio through the utilisation of lean manufacturing processes for the next generation of components is an increasing area of interest in the aerospace industry. Powder bed Electron Beam Melting (EBM) is now rapidly being acknowledged as an innovative form of Additive Layer Manufacturing (ALM) with the potential to produc...
Conference Paper
Full-text available
The use of additive layer manufacturing (ALM) processes such as electron beam melting (EBM) is becoming increasingly prevalent in the aerospace industry. The safety critical nature, coupled with the arduous operating conditions to which these additive manufactured components will be exposed mean that it is crucial that the mechanical properties of...
Conference Paper
Full-text available
Reduction of the buy-to fly ratio through the utilisation of lean manufacturing processes for the next generation of components is an increasing area of interest in the aerospace industry. Powder bed Electron Beam Melting (EBM) is now rapidly being acknowledged as an innovative form of Additive Layer Manufacturing (ALM) with the potential to produc...
Article
In recent years, advances in creep data interpretation have been achieved either by modified Monkman-Grant relationships or through the more contemporary Wilshire equations, which offer the opportunity of predicting long term behaviour extrapolated from short term results. Long term lifing techniques prove extremely useful in creep dominated applic...
Article
Previous literature on gamma titanium alumindes (γ-TiAl) have found that this family of alloys offer significant potential for replacing more conventional nickel and titanium based alloy systems in future designs of gas turbine engines. Despite the inherent brittle nature of such materials, γ-TiAl typically exhibits considerable ductility at elevat...
Article
Small punch testing is now a widely recognised approach for obtaining useful mechanical property information of critical structural components, particularly in the nuclear industry. However, to date the utilisation of this method has been limited to isotropic materials such as aluminium alloys and steels. This paper will look to utilise the small p...
Conference Paper
Full-text available
Additive layer processes are finding increased use in the aerospace industry for the production of complex geometries or localised repair of critical structural components. In support of design and life estimation methods, it is vital that a detailed understanding of the microstructure of these materials and subsequent mechanical properties are obt...
Conference Paper
Full-text available
It is widely acknowledged that creep is one of the most significant damage mechanisms facing the gas turbine sector as designers strive to meet the demanding emissions and fuel burn ACARE (Advisory Council for Aeronautics Research and Innovation in Europe) “Flightpath 2050” targets. Increasing operating temperatures to improve cycle efficiency, in...
Article
Full-text available
A non-invasive temperature measurement, control and profiling technique has been investigated for use with thermomechanical fatigue loading. The technique utilises an infrared thermography camera and Rolls–Royce developed thermal paint to control and monitor cyclic temperature. Thermal paint is used to maintain a stable surface emissivity upon the...
Conference Paper
Full-text available
The requirements for advanced gas turbine jet engines continue to evolve in order to improve operational efficiency through weight reduction and increased operating temperatures, in line with the ACARE (Advisory Council for Aviation Research and Innovation in Europe) 2050 targets. Previous research has focused on advanced cooling designs and therma...
Conference Paper
Full-text available
The Small Punch (SP) creep test has been proven to be an effective method for assessing creep properties where only a limited quantity of material is readily available. At present, it is one of the preferred techniques capable of providing experimental characterisation of service exposed materials from operating components. This laboratory is now d...
Article
The fatigue properties of the high strength stainless steel CSS42L have been evaluated under strain and stress controlled conditions. The results have been used to derive a predictive approach based on the Walker strain equation. Accurate predictions are obtained for VCN and DEN specimens although the lower stress concentration RCN specimen is show...
Article
Full-text available
Microstructural damage and subsequent failures resulting from thermo-mechanical fatigue (TMF) loading within the temperature range 300-700 °C are investigated for the polycrystalline nickel superalloy, RR1000. Strain controlled TMF experiments were conducted over various mechanical strain ranges, encompassing assorted phase angles, using hollow cyl...
Article
Full-text available
Assessment of thermo-mechanical fatigue behaviour of the polycrystalline nickel alloy RR1000 reveals a significant effect of phase angle on fatigue life. The current paper explores two scenarios: the first where the mechanical strain range is held constant and comparisons of the fatigue life are made for different phase angle tests; and secondly, t...