How sintering time and temperature influence fatigue

Mechanical properties of the diffusion alloyed PM' steel Fe-4.0 percent Ni-1.5 percent Cu-0.5 percent Mo+0.6 percent (Ultrapac LE + 0.6 percent C) at the density of 7.1 g/cbcm sintered at 1120 degree Celsius/30 min, 1120 degree Celsius/120 min, 1250 degree Celsius/30 min and 1250 degree Celsius/120 min, were investigated. Fatigue and fracture mechanical properties are significantly improved by the increase of sintering time and temperature due to a better microstructural homogeneity and improved pore's shape. However, as a sintering time of 120 minutes is too long for an industrial mass production the high- temperature sintering at 1250 degree Celsius for a minimum of 30 minutes can be recommended for the manufacture of highly stressed PM' parts.