Effect of boro-sintering process on mechanical properties and wear behaviour of low alloy steel produced by powder metallurgy

Abstract

Boro-sintering is subjecting P/M metal components to boronizing process simultaneously with the sintering process. In this study, powder particles with AISI 1010 steel composition were compressed by cold pressing method under 1000 Psi pressure and then, were subjected to sintering in silicon (Si) and EKabor 2 medium at 1000 °C for 2, 4 and 6 h, respectively. Following the sintering process, the specimens produced by P/M were characterized by optical microscope, Scanning electron microscope, XRD analyses, 2D profilometer, micro hardness and wear test. The porosity values of the samples decreased and the specific gravity and surface roughness increased depend on the increase in borosintering temperature and time. A coating layer, similar to the boride layer formed in the steels, was observed in the specimens sintered with boron. On the other hand, no coating layer was observed in the specimens sintered in Si medium but there was some increase in their surface hardness in a limited area. The boride layer formed on the surface as a result of boro-sintering process has a thickness of 120-150 μm and hardness values of 1300-1500 HV. In this study, it has been proven that sintering and thermal treatment with boron carried out separately in the existing literature have a positive effect on mechanical and wear properties when they are carried out in a single step.