B对Al-7Si合金α相形态和力学性能的影响  

Effects of B Addition on Morphology of Primary α Phase and Mechanical Properties of Hypoeutectic Al-7Si Alloys

作　　者：李小松[1] 蔡安辉[1] 周勇[1] 曾纪杰[1] 

机构地区：[1]湖南理工学院机械工程学院,湖南岳阳414006

出　　处：《有色金属（冶炼部分）》2011年第5期34-37,41,共5页Nonferrous Metals（Extractive Metallurgy)

基　　金：国家自然科学基金资助项目(50874045);湖南省科技计划项目(2010GK3141)

摘　　要：研究了B对Al-7Si合金α相形态和力学性能的影响。结果表明,B对Al-7Si合金具有良好的细化效果;初生α相的形态与大小发生显著变化,树枝晶消失,转变为细小的柱状晶。当加入0.036%B时,组织最理想:形态密实、尺寸细小而均匀,同时,合金的综合力学性能得到了显著的提高,抗拉强度提高15%、延伸率提高68%、断面收缩率提高46%,弹性模量和硬度分别降低22%和9%,细化后Al-7Si合金表现出良好的强韧性。The influence of B addition on microstructure and mechanical properties of Al-7Si alloy was investigated.The results indicated that B had a good refinement effect on Al-7Si alloy.The morphology and size of primary α varied sharply.The α dendrite disappeared and transformed into the refined columnar grains.When B content was up to 0.036%,the morphology of α dendrite was optimal.Meanwhile,the mechanical properties of the alloy had been improved significantly.The tensile strength,elongation rate and percentage reduction of area had been improved by 15%,68% and 46%,respectively.However,Young＇s modulus and hardness had been decreased by 22% and 9%,respectively.

关 键 词：AL-7SI 晶粒细化 组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]