H2 Manufacturing: Hybrid-Hybrid machining of next generation aerospace materials

The application of laser assisted machining/processing has shown promise in reducing tool wear in the machining of difficult-to-machine aerospace materials, such as, metal matrix composites (MMCs). On the other hand, ultrasonically assisted machining has been successfully used to demonstrate essential reductions in cutting forces with an improvement of machined surface quality. This project is a fundamental research programme that aims to comprehensively study the two techniques in combination with a clear route to implementation. Through the transition to hybrid-hybrid manufacturing processes such as the one proposed, UK industries will be able to meet the growing needs of present and future sectors/customers by efficient and sustainable resource usage in the manufacture of future aerospace materials.

The research will focus on the influence of the thermal field-ultrasonic vibrations-mechanical deformation on the MMC material taking into consideration the initial underlying micro-structure of the material. Special attention will be paid to dynamic recrystallization and grain growth of the metallic matrix material due to the influence of the imposed thermal field and deformation-rates (due to machining).

In parallel, a laser-ultrasonically assisted machining system will be designed, developed and installed on an existing CNC machine, with the aim of cutting without coolants, using less force and machining-induced damage. Machining studies will be conducted at industrially relevant machining conditions. Comparisons will be drawn with current practice for
best machining outcomes. It is expected that the new hybrid-hybrid manufacture will lead to less machining forces with reduced tool wear and post machining (tensile) residual stresses.

Finally, several case studies will be conducted with the aim of developing next generation tools for optimal manufacture.

This research program will strengthen the international competitiveness of UK research in materials processing and manufacture and has a direct impact on the aerospace industry. The fast growing energy demand and concerns about climate changes drive industries to implement improved components which will require longer maintenance intervals to achieve high-efficiency power and energy systems. The project outcome will help address this critical need by improving manufacture with the use of Laser and Ultrasonic assistance. This project aims to address some critical shortcoming in knowledge related to deformations in metal matrix composites, through development of accurate numerical models for material deformation and processing. Exploitation of the research outcomes will be carried out with our industrial partners. The research outcomes will provide scientific guidance and support for industries to gain improved machining efficiency during component manufacture. The model developments will enable industries to conduct "numerical experiments", in place of expensive, risky and time-consuming experimental tests wherever possible, and save costs in product development. This will contribute to ensuring the structural integrity and safety under service conditions. Our research team will also take a lead in promoting the impact of the work with the assistance of our existing collaborative network both nationally and internationally.

Key scientific findings generated from the research will have a direct impact on research communities working on advanced manufacture of materials, particularly subtractive manufacture of hard-to-machine materials. The developed predictive modelling tools for material deformation under thermo-vibratory mechanical fields will deliver an underlying generic contribution which should benefit research communities in physics, mathematics and materials engineering. A number of methods will be used to maximise the impact across communities, including publication in journals for different audiences and presentation at a variety of conferences, seminars and workshops. Additionally all research data produced from the project will be archived at LU, which will allow other researchers to access the relevant data and models linked to our published findings.

The proposed research will enable the four post-doctoral research associates (PDRAs) and one PhD student to establish themselves with significant skills and experience in the areas of advanced manufacturing and modelling. The PDRAs, as well as the externally funded PhD student, will help alleviate the critical engineering skills shortage in the UK. This research grant will also be an important step for the investigators to develop and expand their leadership roles in respective fields. Through some of the activities proposed (see Pathways to Impact), the wider public will be engaged due to direct relevance of this research in improving the aerospace and energy sectors. It is expected, the benefits will transcend across all sectors involved in manufacturing of multi-material component parts. School students will be engaged via school visits, by the PDRAs. Academics will also join this effort. The PDRAs will be encouraged to become STEM ambassadors to encourage young people to enjoy STEM subjects and pursue STEM careers. We will provide a number of infrastructure opportunities for researchers to develop research-led engagement activities. Also key summaries about significant findings and developments will be published on our continuously updated website which will be set up from the start of the project. In addition, we will use open days and school visits as opportunities to promote the research programme.