The fifth type is the SPS sintering furnace. SPS sintering furnace is sintering using discharge plasma. Plasma is a state of matter at a high temperature or under a specific excitation. It is the fourth state of matter except in the solid, liquid and gas states. Plasma is an ionized gas, composed of a large number of positive and negative charged particles and neutral particles, and exhibits a collective behavior of a quasi-neutral gas. Plasma is a dissociated high-temperature conductive gas that provides a state of high reactivity. The plasma temperature of 4000~10999℃, its gaseous molecules and atoms are in a highly activated state, and the high degree of ionization in the plasma gas, these properties make the plasma become a very important material preparation and processing technology. The SPS sintering furnace mainly includes the following parts: axial pressure device; water-cooled punch electrode; vacuum cavity; atmosphere control system (vacuum, ammonia); DC pulse power supply and cooling water, displacement measurement, temperature measurement and safety control units. SPS sintering furnace has similarities to thermal pressure (HP), but the heating method is completely different. It is a pressurized sintering method using through-break DC pulse current to directly energize sintering. The main role of the through-break DC pulse current is to produce the discharge plasma, the discharge impact pressure, the joule heat, and the electric field diffusion action. SPS sintering furnace is effective use of the heating of powder. This direct discharge heating method has extremely high thermal efficiency, and the dispersion distribution of the discharge points can achieve uniform heating, so it is easy to prepare a homogeneous, dense and high-quality sintering body. The sintering process of SPS sintering furnace can be regarded as the result of the combination of particle discharge, conductive heating and pressurization. In addition to heating and pressurization, the two factors to promote sintering, the effective discharge between the particles can produce local high temperature, can make the surface local melting, surface material peeling off; high temperature plasma splash and discharge shock to remove the powder particle surface impurities (such as removing surface oxides) and adsorbed gas. The electric field acts to accelerate the diffusion process.