Characterisation of samples from Fe based composite materials prepared by different powder metallurgy techniques

Abstract

Many attempts have been made to manufacture dense metal samples by indirect selective laser sintering (SLS). Unfortunately, current attention focuses on infiltrating low melting metal into SLS samples, which easily worsens their mechanical performances. Therefore, cold isostatic pressing (CIP) was introduced into SLS combined with vacuum sintering (VS) and hot isostatic pressing (HIP) for solving above mentioned problems. Based on powder metallurgy theory, the influences of CIP, VS and HIP on relative densities and mechanical performances of SLS samples were analysed. The results show: relative densities of SLS samples made from Fe–Cu–C increase from 84 to 91˙5 and 95% respectively after CIP at 600 MPa, VS at 1200°C and HIP at 1200°C and 120 MPa; Young's modulus, yield strengths, tensile strengths and elongation percentages of SLS/CIP/hipped samples increase to 139˙5 GPa, 447 MPa, 561 MPa and 7˙9% respectively. Consequently, dense metal samples with better mechanical performances can be manufactured by the hybrid technology.