Stainless steel 316L–hydroxyapatiteudcomposite via powder injection moulding:rheological and mechanical properties characterisation

摘要

Powder injection moulding is a manufacturing process capable of producing complex, precise andudnet-shaped components from metal or ceramic powders at a competitive cost. This studyudinvestigated the rheological properties of stainless steel 316L–hydroxyapatite composite byudusing palm stearin and polyethylene as a binder system, evaluates the physical and mechanicaludproperties, and composition change of the sintered part at different temperatures throughudpowder injection moulding process. Stainless steel 316L powder was mixed with hydroxyapatiteudby adding a binder system (palm stearin and polyethylene) at 58·0 vol% powder loadingudprepared via critical powder volume percentage. A green dumbbell-shaped part was producedudvia plunger-type injection moulding. The green part was sintered at 1000, 1100, 1200 andud1300°C at 3 hours. The value of flow behaviour index n is from 0·1 to 0·39, which is within rangeudof the injectability index. The obtained activation energy is 5·75 kJ mol−1. Morphological resultsudindicate the formation of pores at a sintering temperature of 1000°C, a decrease of pores whenudthe temperature is increased, and the occurrence of densification. At 1300°C it showed the highest mechanical properties of Young’s modulus which is 41·18 GPa. The decomposition of hydroxyapatite into β-tricalcium phosphate and tetracalcium phosphate phases started to occur at 1000 and 1100°C, respectively. The highest sintered density is 3·7744 g cm−3 which is closeudto the density of hydroxyapatite but the mechanical properties is higher than pure hydroxyapatite.