Spark Plasma Sintering: Process Fundamentals

Spark plasma sintering (SPS) is a rapid technique. Its processing parameters are usually low-voltage and low-pressure acting, using a uniaxial force and pulsed direct current (DC) to carry out high efficiency consolidation of the powder. This technique has been widely applied for various materials processing in the recent years. First, a description of its working principles and historical background as well some electrical and thermal effects are presented. Among the numerous proposed physical mechanisms describing the SPS process, the most common is the micro-spark/plasma. This theory is based on electrical discharge and generation of plasma spark with high temperature within a fraction of a second, which forms small local regions between the powder particles. The SPS process is characterized by high heating and cooling rates. We conclude by discussing the advantages of SPS that derive from the microstructural and mechanical properties of the sintered materials. In this chapter, the principles of SPS, its advantages and its disadvantages, are introduced.