Effect of different Y components on optimization of dispersive Y2O3 particles in ODS-Cu

In order to reflect the superiority of using Cu6Y as the Y2O3 source, three different Y sources addition, direct Y2O3 by conventional mechanical alloying process, pure metal Y and Cu6Y compound by in-situ fabrication method, were compared in the ODS-Cu with 1.5 wt.% Y2O3. It was found that compared to Y2O3 or pure metal Y, the brittle Cu6Y played the roles of both suitable Y precursor to enhance Y dissolution and process control agent (PCA) to suppress the growth of mechanical alloying (MA) powders. The alloyed layer was thickened with the MA time, and the further MA gradually becomes difficult. It is inefficient to fully alloy the MA powders only by prolonging milling time. The samples by in-situ fabrication method (Y and Cu6Y sourced) had more contaminations with Fe, because of the oxidation of milling mediums by Cu2O, which was used to oxide the Y precursors to form the Y2O3. The contaminations contributed to the hard prior particles boundaries where fracture took place during the tensile tests, resulting in the poor tensile performance for the samples by in-situ fabrication method. Considering that the Cu6Y sourced sample by in-situ fabrication method formed fine and high dense dispersive Y2O3 particles with the size of 19 ± 7 nm and a high number density of 1.8 × 1021/m3, it has a larger potential for improvement once the means to reduce Fe impurities and holes are developed.