Spark plasma sintering of ODS cobalt base alloy powder by mechanical alloying

Alloyed powder of Cobalt base alloy were prepared by mechanical alloying and bulk alloy was prepared by spark plasma sintering. The experimental results show that the sizes of particle and crystalline grain decrease and the distortions of lattice increase with the milling time during the first stage up to about 8 h, then trends to be slow down. A longer milling time is beneficial to get uniform distribution Of Y2O3 nano-particles in the mixture. The relative density of sintered compact is over 99% by spark plasma sintering at 1100 degrees C for 10 min. Its average grain size is smaller than 5 mu m. After homogenization treatment at 1300 degrees C, the alloy compressive strength and elongation at room temperature are 1982 MPa and 27%, respectively, superior to the cast cobalt base alloy.