Spark plasma sintering is a relatively new sintering method developed in recent years. It uses the instantaneous high temperature field generated by pulse energy and pulse pressure to realize the spontaneous heating of the internal particles of the ceramic to activate the crystal grains. Because of this sintering method The heating and cooling are fast, and the holding time is short, which inhibits the growth of crystal grains, shortens the ceramic preparation cycle, and saves energy. Spark plasma sintering is actually a new hot pressing sintering method. The obtained ceramic samples have uniform crystal grains, high density and good mechanical properties. It is a very valuable and promising sintering method.
In the process of spark plasma sintering to prepare high-purity alumina ceramics, the heating rate has a great influence on the densification of samples at different stages. In the initial stage of sintering, the soft and fast heating rate can increase the density of the sintered body. In the later stage of sintering, the faster heating rate will cause the density of the sintered body to decrease.