摘要
采用光学显微镜、扫描和透射电子显微镜研究了含Ca、Si镁合金的显微组织特征。铸态下,仅含Ca的镁合金主要由镁基体和晶界离异共晶组织(Mg+Mg2Ca)组成;加入约0.5%(质量分数)Si后,晶界离异共晶组织消失,在晶界附近及晶内形成弥散分布的细小点状(球状)、针状和粗块状CaMgSi相;当含Si量较高(约1.0%)时,出现中国字形(针状)的Mg2Si相。固溶时效后,只含Ca的镁合金中晶界处离异共晶组织消失,代之以长大了的颗粒状Mg2Ca相;而Mg Ca Si合金的固溶时效组织较铸态无明显变化。对合金常温和高温短时拉伸性能也作了初步探讨。
The microstructure of magnesium alloys containing Ca and Si were investigated using optical microscope, scanning electron microscope and transmission electron microscopes.The as-cast Mg-Ca alloy containing only Ca is composed of Mg matrix and divorced eutectic (Mg+Mg_2Ca) formed along the grain boundaries. With about 0.5%Si (mass fraction) added to the Mg-Ca alloy to produce Mg-Ca-Si alloys, no grain boundary divorced eutectic is formed any more, instead, dispersive dot-like, needle-like or discrete lump-like CaMgSi compounds are formed at the grain boundaries and within the grains. When the Si content is further increased to about 1.0%, Chinese-character-like (needle like) Mg_2Si compounds are formed in addition to the CaMgSi ones. After solution-ageing treatment, the divorced eutectic (Mg+Mg_2Ca) along the grain boundaries of Mg-Ca alloy containing only Ca disappears, where the grown-up granular Mg_2Ca was found instead, whereas no evident change of microstructure could be found in Mg-Ca-Si alloys. The room temperature tensile properties and elevated temperature transient tensile properties of alloys were also investigated.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2004年第11期1844-1849,共6页
The Chinese Journal of Nonferrous Metals
基金
国家自然科学基金资助项目(50171027)
广东省自然科学基金重点资助项目(013005)
