SAMULET; Project 4: Project 4.3.1: UFG Ti-6Al-4V for Low Temperature/High Productivity DB/SPF and Project 4.3.2: Hot-Die Forging of Titanium Alloys

Lead Research Organisation: University of Strathclyde
Department Name: Design Manufacture and Engineering Man

Abstract

Several process options for the manufacture of components are beset with either quality or economic deficiencies. For example, the cleanliness of surfaces of aerospace components is critical to the production of sound welds using electron-beam welding technology; deficient cleaning methods would result in defective welds. Again, the conversion of Titanium alloys into aerospace components is currently attended to at temperatures at which tool-materials deteriorate rapidly, incurring a prohibitively high tool cost. Converting aerospace materials at high-temperatures would also require specialised tool-materials that are more expensive to cut and capital expenditure that is, typically, four times greater. Current practice is to shoehorn the controlling parameters to enable the manufacture of components. Continuation in this manner is unacceptable from an economic viewpoint. Considering that component designers need to be sufficiently conversant with the geometrical, functional and manufacturing constraints while evolving the form of the component, it follows that new processes, regardless of whether these relate to surface preparation (cleaning), processing at elevated temperatures or to machining to reduce further surface finishing requirements, may only be adopted efficiently, after the critical controlling parameters have been quantified. Project 4: Novel and Transformed Processes, attends to the quantification of the key controlling parameters. Research in the group of novel and transformed processes is with a view to acquiring the know-how to enable the design of components and the associated processes along the value-adding chain. This group refers to the laser cleaning of aerospace materials and components for subsequent processing, since it is known that several defects arise from the failure to meet quality standards. Two aspects of Project 4 refer to the high-temperature conversion of materials into aerospace components. The first of these refers to a new means of manufacturing components at low temperature by introducing a new form of raw material - this ultra-fine-grained variant enables the operation of the conventional processes (diffusion bonding and super-plastic forming) at significantly reduced temperatures, resulting in reduced manufacturing cost. This fine-grained variant will be manufactured and subjected to component forming exercises to demonstrate the new economic balance in manufacturing aerospace components. The second process is hot-die forging of aerospace components. The current practice of bashing Titanium alloys at very high temperatures into a rough form and then whittle away to arrive at the final form is recognised as being expensive. The need to bash the material arises from the fact that the work-material cools too rapidly to operate at the lower forging speeds that can be attended to in presses of lower capital expenditure. If one were to operate at lower temperatures, smaller presses may be used but this balance between bashing the metal at high temperatures and squeezing the work-material at lower temperatures has yet to be defined. The proposed research will define the parameters critical to operating at lower temperatures. The final project refers to an elegant approach to removing the excess materials remaining on components in a manner that reduces the amount of additional downstream processing of surfaces to meet performance standards. By quantifying the character of the cutting tool and the machine on which excess material is removed, the technology will enable the operation of the metal-removal system in a manner that recognises the fact that the character of both, the cutting tool and the machine-tool influence the cut surfaces. Each separate process will assume a role in more cost-effective conversion of raw materials for the aerospace industrial sector and would also impact on the nuclear and automotive industrial sectors.

Publications

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Description From the industrial partner (Rolls Royce) point of view, the project was finished within three years after achieving its industrial goals. These were: feasibility of using fine grained titanium alloys for low temperature DB/SPF of wide chord fan blades and characterisation of the main materials and heat exchange conditions during forging of compressor blades. For University of Strathclyde it meant engagement in a very advanced and unique research for the leading aerospace company, which resulted in generation of both the applied and the fundamental knowledge. The project was given a one year extension, which enabled further development of severe deformation technology at University of Strathclyde based on an original process of incremental equal channel angular pressing, which enables processing long bars, plates and sheets. This technology can be used to produce ultrafine grained metals with improved properties such as aluminium, titanium, magnesium and iron.
Exploitation Route Rolls Royce has engaged in another Samulet project (with AFRC) to explore further improvements to their SPD/DB processes used for manufacturing of aerospace components. UFG metals can also be used in other manufacturing sectors, for example, forging of medical implants. This option was taken forward within the framework of an Innovate UK feasibility study project led by industry.
Sectors Aerospace, Defence and Marine,Healthcare

 
Description This project was one of the first projects obtained by the University of Strathclyde Advanced Forming Research Centre (AFRC), part of the HVM Catapult Centre. It helped in the successful launch of the AFRC, which is now a large research facility attracting investment of approximately £40 millions and employing 140 skilled workers. The creation and development of AFRC has impacted on UK policy in the area of advanced manufacturing and been instrumental in shaping the government investment profile for this sector.
Impact Types Economic

 
Description Forging of ultrafine grained commercial purity titanium orthopaedic implants
Amount £90,600 (GBP)
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 04/2015 
End 02/2016
 
Title Mechanical testing after I-ECAP at 250 C and 200 C 
Description "Datasets (CSV files) from mechanical testing of fine-grained AZ31B magnesium alloy obtained by I-ECAP at 250 C and 200 C. Mechanical properties were investigated using an Instron 5969 testing machine with the maximum load capacity 50 kN. Tension and compression tests were carried out at room temperature with the initial strain rate equal to 1, 10-3 s-1. All specimens were cut out along ED. Flat tensile specimens, with thickness equal to 2 mm and dimensions of the gauge section 2.5 mm, 14 mm, were machined using wire electrical discharge machining (EDM).Height and diameter of the compression specimens were 8 mm and 7 mm, respectively. This dataset relates to the EPSRC funded SAMULET Project 4 Task 4.3.1 and Task 4.3.2 (EP/G03477X/1)." 
Type Of Material Database/Collection of data 
Year Produced 2015 
Provided To Others? Yes  
Impact
 
Description Joint research with BAE Systems (Operations) Ltd. 
Organisation BAE Systems
Country United Kingdom 
Sector Private 
PI Contribution University of Strathclyde researchers worked on this project with researchers from BAE Systems (Operations) Ltd.
Start Year 2010
 
Description Joint research with LOUGHBOROUGH UNIVERSITY 
Organisation Loughborough University
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from LOUGHBOROUGH UNIVERSITY
Start Year 2010
 
Description Joint research with Rolls-Royce PLC 
Organisation Rolls Royce Group Plc
Country United Kingdom 
Sector Private 
PI Contribution University of Strathclyde researchers worked on this project with researchers from Rolls-Royce PLC
Start Year 2010
 
Description Joint research with University of Birmingham 
Organisation University of Birmingham
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from University of Birmingham
Start Year 2010
 
Description Joint research with University of Manchester 
Organisation University of Manchester
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from University of Manchester
Start Year 2010
 
Description Joint research with University of Nottingham 
Organisation University of Nottingham
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from University of Nottingham
Start Year 2010
 
Description Joint research with University of Southampton 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from University of Southampton
Start Year 2010