Suresh Palanisamy

Cold spray additive manufacturing (CSAM) is generally used to repair worn components and build complex on-demand parts by depositing metal powder layer-wise using compressed air. Previous studies on CSAM were focused on printing parameters, materials properties, and printed part mechanical performance. However, the energy consumption and environmental impacts of CSAM processes have not yet been investigated, which are essential factors for sustainable manufacturing. This study aims to investigate the carbon footprint of the CSAM process and compare it with conventional machining processes and other additive manufacturing. The life cycle assessment methodology was followed to calculate the carbon footprint of a pipe flange, considering rod or tube as a feedstock. Results revealed that the machined flange from the tube had the lowest CO2-eq emissions of 31 kg CO2-eq due to low rough machining energy consumption and scrap production, compared to the machined flange from a rod and a printed flange from powder. Moreover, the life cycle carbon emissions increased by 8% and 19% in case of the printed and machined flanges, with uncertainties of 4% and 9%, respectively, when changing feedstock CO2 emissions. From a regional perspective, the CSAM process was responsible for the lowest CO2-eq emissions in Tasmania and South Australia.

The necessity for biomedical components is increasing every year. However, Ti6Al4V, the most widely utilized titanium alloy for biomedical implants are very costly owing to the high price of V alloying element. Furthermore, both alloying elements Al and V, have adverse effects in human body which is not desirable. This review paper highlights significant findings on alloy design using low-cost alloying elements, their processing routes, and their relationship to microstructural, mechanical, and biological properties. Mo, Fe, Mn, Zr, and Cu were identified as low-cost alloying elements and fabrication of titanium alloys with these elements are usually carried out using arc melting, investment casting, powder metallurgy, additive manufacturing, diffusion couple, and thermomechanical processing. Several processing routes can be chosen to obtain optimum properties such as β-phase titanium alloy structure, low elastic modulus, and high strength. Alloy design, post-heat treatment process, and fatigue test for newly developed alloys are research that can be carried out in the future for the development of new titanium materials that are safe for human use and at a more affordable price.