学术
Ho对AZ91镁合金显微组织和力学性能的影响
宋雨来[1] 刘耀辉[1,2] 朱先勇[1] 王强[1]
[1]吉林大学材料科学与工程学院,吉林长春130025 [2]吉林大学教育部汽车材料重点实验室,吉林长春130025
摘 要:
采用扫描电镜观察、X射线衍射和拉伸试验等方法对稀土钬（Ho）改性Mg-9Al—1Zn（AZ91）镁合金的显微组织和力学性能进行了研究．结果表明：Ho能够充分细化AZ91镁合金中的α—Mg和β—Mg17Al12晶粒，抑制二次β-Mg17Al12的析出，使不完全离异共晶转化为离异共晶，并在合金中生成颗粒状Al2Ho金属间化合物．Ho通过细晶强化增加了合金强度，改善了塑性，使合金的断裂机制从脆性解理断裂转变为准解理断裂、[著者文摘]
文章出处:
《湖南大学学报：自然科学版》-2008年35卷3期 -67-71页
栏目信息:
分 类 号:
文献标识码:
A
文章编号:
1000-2472（2008）03-0067-05
Effect of Ho on the Microstructure and Mechanical Properties of AZ91 Magnesium Alloys
SONG Yu-lai, LIU Yao-hui, ZHU Xian-yong, WANG Qiang （ 1. School of Materials Science and Engineering, Jilin Univ, Changchun, Jilin 130025,China; 2, Key Laboratory of Automobile Materials of Ministry of Education, Jilin Univ, Changchun, Jilin 130025, China）
Abstract:
The microstructures and mechanical properties of an Mg-9Al-1 Zn （AZ91） magnesium alloy modified by holmium （Ho） were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and tensile tests. The results have indicated that Ho sufficiently refines α-Mg and β-Mg17Al12 grains, suppresses the precipitation of secondary β-Mg17Al12, and the eutectic behavior varies from partially divorced eutectic to fully divorced eutectic. In addition, Ho forms Al2Ho intermetallic compounds. Ho effectively increases the tensile strength and ductility of AZ91 magnesium alloys due to the fine-grained strength. The fracture mechanism of alloy changes from brittle cleavage into quasi-cleavage failure.[著者文摘]
Key words:
magnesium alloys;holmium;microstructure;mechanical properties
基金资助:
国家博士点基金资助项目（20040183072）;吉林省科技发展重大项目（20040315）;长春市科技支撑计划资助项目（2007KZ04）
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