摘要
利用光学显微镜、扫描电镜、X射线衍射分析及高温压缩蠕变装置等,研究了稀土元素Gd对Mg-7Al-1Si合金显微组织及蠕变性能的影响。结果表明,适量Gd的加入能明显细化Mg-7Al-1Si合金的晶粒尺寸、改善Mg2Si相的形态,使β相分布更弥散,并提高了合金的抗高温蠕变性能,Gd的加入还使基体中出现新相Al2Gd。Gd含量为1.0%时,合金的组织和成分均匀,细化效果最好,抗高温蠕变性能也最佳。此时晶粒平均尺寸由79.08μm减小到39.12μm,β相含量由10.88%减少到6.98%,同时Mg2Si相形态明显改善,由粗大汉字状变为短杆状及颗粒状,从而提高了合金的抗高温蠕变性能。
Effects of Gd on microstructure and compressive creep behavior of Mg-7AI-ISi alloy were in- vestigated by optical microscopy （OM）, scanning electron microscope（SEM）, X-ray diffraction analysis （XRD） and high temperature compressive creep apparatus. The results show that proper Gd addition can greatly refine the as-cast microstructure and improve the morphology of Mg2 Si phase as well as mak- ing theβ phase more dispersed distribution, so the elevated creep behavior of the alloy is improved. In addition, A12Gd particulate appears in the matrix. The microstructure and composition of Mg-7Al-lSi alloys are more homogeneous with 1.0 % Gd and desirable grain refinement and high creep resistance can be obtained, where the average grain size is decreased from 79.08 μm to 39.12μm, and theβ phase con- tent are decreased from 10.88% to 6.98%, while the morphology of the Mg2Si phases is changes from coarse Chinese script shape to short rod or fine particle. Accordingly, the creep properties of the alloy are improved greatly.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2014年第4期346-349,共4页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(51305345)
材料腐蚀与防护四川省重点实验室资助项目(2013CL09)
