Development of Gas Pressure Sintered Silicon Nitride and Its Automotive and industrial Application

The gas pressure sintering (GPS) process of silicon nitride is capable of producing sintered material of better quality than that obtained with the conventional normal sintering methods, and can be performed in a procedure simpler than the HIP method. These features of the GPS process have made it a promising manufacturing process for high quality silicon nitride ceramics. However, because sintering is performed in a high pressure atmosphere in this process, a 2-step sintering method had to be developed before applying it to practical industrial manufacture.

The gas pressure sintered silicon nitride (GPSSN) ceramics densified to high density have already been used in turbocharger rotors for automotive applications, cutting tools, and bearing balls for industrial applications, etc., and have been highly evaluated for high strength and reliability.