Hybrid microwave sintering of Fe-Cr-Cu

Abstract

Metal Matrix Composites (MMCs) are generally utilized as a part of structure applications. The motivation to create them is to enhance mechanical properties of the solid material. Unfortunately, in the previous years the vast majority of metal network MMCs are being created by powder metallurgy (PM) and sintered by conventional sintering process. Due to low heating rate, sintering with conventional sintering is long time process beside consume high electrical energy and sample are adequate for conventional application. To solve this issue, sintering under microwave energy is one of the option. This study is attempted to investigate the impact of copper (Cu) expansion on the iron-chromium matrix fabricated by PM route followed by sintering under hybrid microwave energy. Microwave furnace at frequency 300 GHz with maximum power of 3.0 kW was used in the sintering process. The evaluations are based on density, porosity, micro hardness and compressive strength. The result show that the density increased and porosity decreased with percentage powder material. The highest hardness of the composite was 160 Hv which was significantly improved, mainly caused by copper addition in the matrix. Furthermore, increasing in sintering temperature and soaking time also promoted better densification. However, addition of copper particle causing an adverse effect due to agglomeration of copper particle resulted in deterioration of densification. Composites containing higher volume portion of copper particulates displayed higher wear resistance. Lastly, the hybrid microwave sintering resulted in higher density, lower in porosity with better microstructure.