Numerical study on thermal-electrical phenomena in spark plasma sintering with varying specimen size

Spark plasma sintering (SPS) is recognized as a single step processing procedure, which sinters materials using electric current in conjunction with uniaxial pressure. SPS has many important technological benefits over the conventional sintering techniques e.g., fewer processing steps, possibility of higher heating rates, controlling the grain growth, near net shape capacity, elimination of the need for sintering aids and improving the physical, chemical and mechanical properties of powder materials. As this process is relatively newer, it is not fully investigated. In addition, the different physical parameters like temperature, pressure, etc can't be measured experimentally inside the sample, it is vital to find them using computational techniques in order to get a better understanding of the process. Later on, these computational models can be used in the optimization of the process and designing of newer products especially products in shapes other than the disc shape. The present paper addresses the development of a coupled electrical-thermal Finite Element model of SPS process. Numerical simulations are carried out for two samples (aluminum and alumina). The distribution of electric current and temperature are shown in the specimen as well as in the tooling for different aspect ratio of disc shaped specimen.