掺杂复合稀土氧化物对W-20Cu复合材料组织与性能的影响（英文）

Effect of Rare Earth Oxide Addition on the Microstructure and Properties of Ultrafine Grain W-20Cu Composites

以偏钨酸铵和硝酸铜为原料,采用EDTA-柠檬酸法制备了含有0%～0.8%(质量分数)稀土氧化物(Ce_(0.8)Sm_(0.2)O_(1.9),SDC)的W-20Cu复合粉体,所制备的复合粉体经压制成形、1250℃烧结2 h后获得SDC/W-20Cu复合材料烧结体。对所制备复合粉体进行物相、形貌的表征;研究稀土氧化物的添加对SDC/W-20Cu烧结体的密度、组织结构和物理力学性能的影响。结果表明:所制备的W-Cu复合粉体平均粒度为100～200 nm;同时,SDC的添加对烧结体的密度和电导率会有轻微的影响,但能够抑制晶粒的长大并明显改善烧结体的力学性能。经1250℃烧结后,SDC/W-20Cu烧结体的相对密度均高于97%;当SDC的添加量为0.6%时,具有最大的抗弯强度和显微硬度HV,分别是1128 MPa和3180 MPa;此外,在室温和600℃的测试条件下,其最大的抗拉强度分别可以达到580和258 MPa。

Ultrafine W-20 wt%Cu（W-20 Cu） powders doped with 0 wt%～0.8 wt% rare earth oxides Ce0.8Sm0.2O1.9（SDC） were synthesized by the EDTA-citrate method using ammonium metatungstate and copper nitrate as raw materials,and the resultant powders were pressed and sintered at 1250 ℃ in H2 atmosphere for 2 h to obtain SDC/W-20 Cu composites.Morphology of the SDC/W-20 Cu powders and microstructure of the sintered SDC/W-20 Cu composites were observed by SEM,and density,physical and mechanical property of sintered SDC/W-20 Cu composites were also tested to investigate the influence of rare earth addition.The results show that the SDC/W-20 Cu powders are irregular in shape with particle size ranging from 100 nm to 200 nm.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-20 Cu composites.The sintered SDC/W-20 Cu samples have relative density above 97%.Bending strength and micro-hardness HV of the SDC/W-20 Cu specimens are 1128 MPa and 3180 MPa with the addition of 0.6 wt% SDC,respectively,and the highest tensile strength reaches 580 MPa and 258 MPa at room temperature and 600℃,respectively.