Metal Injection Molding (MIM) is a method of producing complex metal parts in which powder metallurgy and plastic forming are combined. In the MIM process, 316L stainless steel powder can be sprayed by gas atomization or water atomization.
Regarding the corrosion resistance of 316L stainless steel, in the MIM process, whether it is gas atomization or water atomization
The key factors mainly depend on the chemical composition, microstructure and defects that may be introduced during the preparation of the raw powder.
Atomization: Atomization is a method of spraying metal powder into fine droplets. When gas atomization is used in the MIM process, 316L stainless steel powder interacts with the gas flow to form fine droplets. During the subsequent forming and sintering process, these droplets will form the metal part.
For the corrosion resistance of 316L stainless steel, the gas atomization technology itself will not have a direct impact on the chemical composition and corrosion resistance of the material. However, the gas atomization conditions during the preparation process and subsequent sintering may affect the microstructure and defects of the material.
Water atomization: Water atomization is a method of spraying metal powder into fine droplets with water as the atomization medium. Water atomization produces finer droplets than air atomization and provides cooling during the spraying process.
Water atomization may have a weaker effect on the corrosion resistance of 316L stainless steel than gas atomization. Due to the cooling effect during the water atomization process, the grain size and grain boundary structure of the material may be affected, thereby having a certain impact on the corrosion resistance. However, this effect is usually weak and can be tuned and optimized through subsequent sintering and heat treatment processes.
In general, in the MIM process of 316L stainless steel, whether it is gas atomization or water atomization, the key factors determining the corrosion resistance of the material are mainly the chemical composition of the raw powder and the microstructure control during the preparation process. For demanding corrosion-resistant applications, MIM-formed 316L stainless steel typically requires further sintering and processing to optimize the material's microstructure and corrosion resistance.