Abstract：Metal-powder injection molding (MIM) was an excellent choice for small metal parts with complex
shapes. In particular, iron-based alloys with a weight less than 50 g had become a very popular technical option in
China and Global. However, it is still difficult to manufacture precision gears with MIM because gears are parts
with high repeatability requirements. This paper attempts to use precipitation hardening stainless steel-17-4PH to
make spur gears, observe and compare the distortion of MIM products and design models in the thickness direc‐
tion. 17-4PH was the most commonly used in MIM industry. According to the pilot experiment results, the thick‐
ness direction distortion of MIM sintered spur gear is found to be 0.07-0.08 mm. After modifying the tooling and
adjusting the MIM forming parameters (include injection parameters, green body placement mode, and sintering pa‐
rameter design), the thickness direction distortion of the spur gear can be improved to 0.02-0.03 mm. After check‐
ing the American Gear Manufactures Association (ANSI/AGMA 2000-A88) table, it is found that MIM gear prod‐
ucts can reach the Q9 grade.
李杰，叶德全，邱耀弘. 改善金属注射成形制作17-4PH直齿轮厚度方向的失真度[J]. 粉末冶金工业, 2022, 32(06): 64-69.
LI Jie，YE Dequan，QIU Yaohong. Improving the thickness direction deviation of 17-4PH spur gear made by metal-powder injection molding. Powder Metallurgy Industry, 2022, 32(06): 64-69.
2022, Vol. 32 
