Effects of pulse conditions on microstructure and mechanical properties of Si3N4/6061Al composites prepared by spark plasma sintering (SPS)

In this paper, 30% Si3N4/6061Al composites were prepared by SPS process to study the influence of different pulses on the microstructure and mechanical properties of the composites. The results showed that there was a sintered connection of the reinforcement Si3N4 in the composite. Moreover, with the decrease of the value of pulse condition ton: toff, the increased current would lead a rise of the local temperature in the composites, thus the connection of the Si3N4 particles became serious. At the same time, the interfacial reaction became serious, and the interface morphology changed from smooth to steep and then to serration. The results of mechanical properties analysis showed that different pulse conditions had little effect on the tensile strength of composites, but they had a greater effect on the elastic modulus and plasticity. When the pulse condition was ton: toff = 2:1, the composite had the best mechanical properties and was superior to the performance given in many literature currently. This paper attempts to provide a certain experimental basis for the preparation of aluminum matrix composites by SPS. © 2018 Elsevier B.V.