Co-Powder Injection Moulding (Co-PIM) Processing of Titanium Alloy (Ti-6Al-4V) and Hydroxyapatite (HA)

Co-powder injection moulding (Co-PIM) is a metal/ceramic injection moulding that offers co-injection of two materials, which effectively reduces the cost and surface engineered component's development. However, co-injection of metal and ceramics is still lacking due to the limitation of different material properties. The purpose of this study was to investigate a co-injection of Ti-6Al-4V and HA experimentally. Three different solid loadings (68, 69, and 70 vol%) of Ti-6Al-4V feedstocks were co-injected with 56 vol% of HA. The binder composition added was 60 vol% polyethylene (PE) and 40 vol % palm stearin (PS). The Co-PIM green part of Ti-6Al-4V and HA diffused well at injection processing parameters of injection melting temperature 150°C, mould temperature 90°C, injection pressure 10 bars, and holding time 10s, respectively. The result shows that the bonding strength increased proportionally to the increasing volume of Ti-6Al-4V. The 70 vol% Ti-6Al-4V/56 vol% HA shows the highest density and bonding strength of 2.72g/cm3 and 2.27MPa was approximately achieved. In addition, the binder systems improved the bonding mechanism of the green part without cracks appeared at the bonding of two materials.