Preparation and Properties of Ultrafine Grain W-20Cu Composites Doped with Rare Earth Oxides

摘要

To obtain W-Cu composites with improved microstructure and properties, ultrafine W-20wt.%Cu(W-20Cu) powders doped with 0-0.8 wt.% rare earth oxides (Ce_(0.8)Sm_(0.2)O_(1.9), SDC) were synthesized by the EDTA-citrate method, and SDC/W-20Cu composites were prepared by sintering the powder compacts. The test results show that the SDC/W-20Cu powders have irregular shape with particle size ranging from 100 to 200 nm. The sintered W-20Cu samples have relative density above 97%. The addition of SDC has slight influence on the electrical conductivity, but obviously refines the grain size and improves the mechanical properties of the W-20Cu composites. Bending strength and hardness of the W-20Cu specimens increase by 14.5% and 13.2% with the addition of 0.6wt.% SDC, respectively, and the highest tensile strength reaches 580MPa and 258MPa at room temperature and 600°C, respectively.