AFRC_CATX_1677_X centre 2019 RiR Jon Willmott

Temperature is a critical process variable throughout much of manufacturing. The AFRC has a suite of high value manufacturing processes where accurate temperature measurement is essential to improve process control, enhance yield, reduce energy use, and increase manufacturing productivity. However, the measurement of temperature in manufacturing environments is notoriously difficult. Measurements are often uncertain and inaccurate, complicated by a multitude of problems including unknown or changing emissivity, stray radiation and atmospheric absorption – to name a few. Many advanced processes require the simultaneous measurement of temperature at high speed, sensitivity and spatial resolution. To solve these challenges new approaches and the development of new technologies are required. This Research Residency will allow Dr Willmott to:

• Provide AFRC with expert consultancy on thermal metrology and best practice.
• Develop a detailed understanding of AFRC’s processes and challenges.
• Devise sensor system concepts and demonstrators that solve these challenges.
• Secure both basic and translational research funding to take concepts forward to application.

Dr Willmott has already developed thermal metrology systems for the AFRC during his previous role at AMETEK-Land (AFRC Tier2 partner). There were many opportunities for research collaborations that were held back by the need to use standard instruments and insufficient time to work up projects. Having moved to academia as an EPSRC Manufacturing Fellow and spent three years building a research group at the University of Sheffield, he is now in the ideal position to have impact on advanced forming and forging research that he aspired to some years ago.

Temperature is particularly important to AFRC’s research due to the high temperature nature of their work. AFRC’s core research programme is: incremental bulk deformations; residual stress; hot bulk forging, materials and process modelling; hot sheet forming; low temperature sheet forming; heating technologies and modelling; tooling, surface and process monitoring. Their programme, therefore, has the need for precise and accurate temperature measurement and control running through it. Advances in sensor systems for thermal metrology can unlock progress in all these areas of forming and forging.

Summary of processes and challenges

Dr Willmott and AFRC have co-created a range of challenges for seed projects together from discussions with Aurik Andreu (Heating Technology Lead), Remi Zante (Senior Technology Officer) and Sheena MacKenzie (Future Business Manager). The key processes for focus include flow forming and radial forging with specific temperature measurement needs including:

• Monitoring of forging die during operation (approx. 200-800°C)
• Monitoring of metal part during transfer from furnace to the press (approx. 800- 1100°C).
• Monitoring of metal part during rotary forging process (approx. 250°C max).
• Measurement during heat treatment of parts and door opening in Gas Furnace: direct view or through quartz window (approx. 800-1100°C)

The specific challenges and research questions include:
• The presence of lubricants on surfaces (e.g. during die forging) complicates accurate measurements. Can this be accounted for via e.g. filtering?
• Improving the accuracy of emissivity measurements, starting with comparing the the approaches and techniques at AFRC and Sheffield to measure emissivity of materials at various temperatures, wavelength and surface states.
• How to devise emissivity compensation algorithms for a range of different alloys materials including Nickel alloys; Titanium alloys; Stainless and alloys steel, aluminium alloys. Temperature range depends on the applications/materials (see above) (1400°C max temp in use at the AFRC)
• Can we fingerprint materials and phases with hyperspectral thermometry?
• How to thermally image through water during quenching.
• Maintaining and monitoring phase during forming, e.g., superplasticity.

Background to the Collaboration

Dr Willmott first visited AFRC in 2011 when AMETEK Land, became a Tier2 member. An example of the work he undertook is a project on thermal imaging of billets coated in glass powder, heated by induction. The idea was to use thermal imaging to control the rapid heating – with a potential huge impact on AFRC partners, such as Mettis Aerospace’s processes, by reducing heating time and dramatically reducing energy costs, their biggest overhead. Unfortunately, the approach proved unreliable due to rapidly changing emissivity during the glass phase change. As a result, Dr Willmott produced a design for AFRC, of an instrument to measure emissivity. To our knowledge, this instrument (now in use at AFRC), provides the only scientifically robust emissivity instruments outside the German and US National Measurement Institutes. Due to personnel changes at AFRC and Dr Willmott’s move to Sheffield, it was not until the recent MAPP EPSRC Future Manufacturing Hub workshop that Dr Willmott reconnected with AFRC. This Research Residency will build on this successful track record but now with the resources and flexibility of his EPSRC Fellowship and research group to enable deeper collaborations on many new areas of research.

Generalised Methodology and Approach

Dr Wilmott has a range of different sensor systems, including radiation thermometers, fibreoptic thermometers, high quality thermocouples, novel single pixel cameras and repurposed/improved commercial cameras that his group uses for thermal imaging research. These tools are currently being applied to a range of real-world manufacturing problems with partners including Land Instruments, Reliance Precision, TWI and Tata. In particular relevance to AFRC and their metrology partners, he has a deep knowledge of all current AMETEK Land instrument designs. Dr Willmott, therefore, has access to a huge range of adaptable tools to solve AFRC thermal metrology problems. As part of Dr Willmott’s EPSRC Manufacturing Fellowship, he can also introduce novel semiconductors and novel printed electronics sensors to the research.

The aim is to develop and deliver a portfolio of projects. The Work-Plan has been developed with the aim of realising both short-term deliverables via the adaptation or modification of existing approaches and the longer-term development of new solutions. The approach will involve
• Begin work on the seed projects identified above.
• Applying or adapting our existing instruments, measurements and models for these projects. Where this is not possible, consider developing a new instrument, algorithm or technique if there are sufficient resources (within the Catapult RiR budget and with a supporting PhD student).
• Where there are insufficient resources, develop research proposals and/or work with AFRC industrial partners to produce a new solution.
• During seed project work, extensively network at AFRC and understand their workflows, research strategies and projects that Dr Willmott group’s technologies can usefully contribute to. In-so-doing, develop high quality proposals for basic or applied scientific research in sensor systems for forming and forging that can address these opportunities.