Electron Beam Melting with Titanium Alloy for Orthopaedic Applications

Ti-6Al-4V is a commonly used high specification metal alloy due to its high specific strength, corrosion resistance and good biocompatibility. This combination of properties makes it high in demand in the medical industry for maxillofacial and musculoskeletal implants, where the need to withstand repeated loading is essential for product function.
However, the fatigue strength is detrimentally affected by porosity found within products. This project will analyse variables associated with the Electron Beam Melting powder bed additive manufacture process and relate these to porosity. The aim is to establish knowledge on the sources of porosity which can be implemented within a quality system to avoid the creation of porosity, allowing the creation of repeatable properties from batch to batch, establishing a standardised process for high performance functional implants.

Additive Manufacturing (AM) is the direct production of end-use component parts made using additive layer manufacturing technologies. AM enables the manufacture of geometrically complex, low to medium volume production components in a range of materials, with little, if any, fixed tooling or manual intervention beyond the initial product design. It enables a number of value chain configurations, such as personalised component part manufacture but also economic low volume production within high cost base economies. The concept of AM is to use the layer approach to add value to a component part during manufacture. This Centre for Doctoral Training in Additive Manufacturing has been developed to bring about a formalised and innovative training structure to make the best of the human capital being graduated from Universities and allow them to embark on a tailored programme of doctoral training specifically in AM. Current training for AM is disparate and sporadic with no formal doctoral training available in the UK. However, AM is recognised by government and industry as being a key technology for the UK, and one that will allow the UK to maintain and grow its high-value manufacturing sector. AM provides a basis for long-term innovation within UK manufacturing and in particular, the concept of 'growing' entire components offers significant benefit to the high-value manufacturing sector, based on innovative design solutions. AM is cross-sectoral in nature, and with the development of the multi-functional AM is increasing in its diversity and the requirements for multi-disciplinary research are increasing, engagement with students and academics from varying disciplines, Chemistry/Biological Sciences/Physics etc. is a key requirement to make the most of the UK's research lead. In concert, industrial contacts are broadening, previous engagement from industries such as automotive and aerospace continues. However, basic materials companies, software and specialist manufacturing companies are now seeing AM as a route to market or exploitation of their products and / or services.
The current AM market place for machine tools, materials and services (such as software) is valued at just over $1.2Billion. However, it must be acknowledged that AM is an enabling technology. But, fundamentally, AM adds the greatest value in its application and taking an AM philosophy can result, through design freedoms, production flexibility and supply chain economics changes to the traditional manufacturing model that can provide business benefits unrealisable with conventional manufacturing technology. In the medium to long term, the opportunities for AM are significant and diverse, and through this philosophy, the CDT's industrial partners want to enable the next generation of AM processes, materials, software tools and supply chains.
It can thus be seen that there will be multiple beneficiaries from the CDT's establishment. The CDT's industrial supporters represent a variety of end user industries - both multinational and SMEs - together with the equipment and systems manufacturers and suppliers representing the value chain. The benefits from trained scientists and engineers and new AM technology and processes enables new product and market opportunities in diverse sectors, and economies in production of existing components and systems, whilst supplying the ready-made human resources to augment these developments within industry and academia. The requirement for students to undertake internships at these companies during their studies means that these companies will have a pipeline of talent to work with and employ in the future. From a wider perspective, the UK will benefit through increased competitive advantage of its manufacturing industries, and the public will gain through new products at economic costs. For society the AM offers the environmental gain of lower carbon footprints and more sustainable use of precious raw materials.