【摘要】 采用XJG 04型金相显微镜、JCXA 733电子探针、D/max rB型X射线衍射仪及WDW 200型电子万能实验机研究了Y对Mg 0 8Zr 0 35Zn基合金铸态、固溶时效组织及高温(250℃)性能的影响。结果表明:Y能细化Mg 0 8Zr 0 35Zn基合金铸态及热处理态组织,加入Y形成新相Mg24Y5。在250℃时,随着Y含量增加合金高温抗拉强度增大,延伸率及断面收缩率降低;高温拉伸断口SEM图像显示脆性断裂趋势增大,断裂由延性向解理方式发展。更多还原

【Abstract】 The effects of Y addition on microstructures and elevated temperature （250 ℃） properties of as-cast and solid solution and ageing treatment Mg-0.8Zr-0.35Zn base alloys were investigated by using XJG-04 optical microscopy, JCXA-733 electron probe, D/max-rB X-ray diffractometer and WDW-200 electronic universal material testing machine. The results show that the microstructures of as-cast and heat treated Mg-0.8Zr-0.35Zn base alloys with addition of Y are refined and a kind of new phase, Mg₂₄Y₅, is formed. At 250 ℃, the elevated temperature strength of the alloys is increased with the increasing amount of Y addition, but elongation and section reduction are decreased. The tendency of brittle fracture of elevated temperature fracture section is enlarged and alloys are transferred from ductile fracture to cleavage fracture.更多还原