Mg-Al-Zn合金半固态坯的制备及触变成形研究  

Research on Preparation and Thixoforming of Mg-Al-Zn Alloy Semi-solid Billets

作　　者：姜巨福[1] 王迎[1] 罗守靖[1] 杜之明[1] 

机构地区：[1]哈尔滨工业大学

出　　处：《特种铸造及有色合金》2007年第S1期368-371,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50605015)

摘　　要：通过新SIMA法制备Mg-Al-Zn合金半固态坯的触变挤压和触变模锻试验以及借助金相显微镜、拉伸试验机等分析手段对Mg-Al-Zn合金半固态坯的制备及触变成形进行了研究。研究结果表明,新SIMA法中的等径道角挤压能使Mg-Al-Zn合金获得良好的应变诱导效果,即铸坯微观组织被大大细化,平均晶粒尺寸达到20μm,材料力学性大幅度提高;该坯料在560℃保温20min制备的半固态坯料的固相晶粒细小,球化程度高,组织均匀,平均晶粒尺寸为25μm。通过触变挤压和触变模锻试验证明新SIMA法制备的Mg-Al-Zn合金半固态坯料所触变成形的零件的力学性能很高。其中触变挤压的卫星角框零件的屈服强度、抗拉强度和伸长率分别为213.1MPa、312.6MPa和15.2%。触变模锻的托弹板零件的屈服强度、抗拉强度和伸长率分别为218.6MPa、320.9MPa和14.8%。Preparation and thixoforming of Mg-Al-Zn alloy semi-solid billets were investigated by means of metalloscope and tensile testing machine, in which new SIMA method, thxoextrusion and thixoforging experiments were employed as preparing Mg-Al-Zn alloy semi-solid billets and studying their thixoforming, respectively. The results show that good strain induction effect of as-cast Mg-Al-Zn alloy can be obtained by equal channel angular extrusion (ECAE) in new SIMA method, i.d.microstructure of as-cast Mg-Al-Zn alloy was refined to average grain size of 20 μm and mechanical properties of as-cast Mg-Al-Zn alloy were enhanced greatly. When these billets extruded by ECAE were held for 20min at 560 ℃, semi-solid billets of Mg-Al-Zn alloy with fine, spheroidal and homogeneous solid grains were prepared and average grain size was 25 μm. The results of thixoextrusion and thixoforging experiments of satellite angle frame and magazine plate components show that mechanical properties of components were enchanced greatly. Yield strengh, ultimate tensile strength and elongation of satellite angle frame are 213.1 MPa,312.6 MPa and15.2, respectively. Yield strengh, ultimate tensile strength and elongation of magazine plate are 218.6 MPa,320.9 MPa and14.8, respectively.

关 键 词：Mg-Al-Zn合金 等径道角挤压 新SIMA法 半固态坯 触变成形 

分 类 号：TG249.9[金属学及工艺—铸造]