摘要
通过流动性、热裂性和力学性能测试,借助OM、DSC、相图和SEM分析,研究不同Ti添加量对Al-7%Mg（质量分数）合金微观组织及性能的影响。结果表明：随Ti含量增加,Al-7%Mg合金晶粒组织细化与等轴化,晶界变得明显,共晶组织含量增加;流动性先提高后降低,添加0.2%Ti的合金,其平均流动长度达到597 mm,热裂倾向明显降低,当Ti含量增加到0.5%时,样品基本不产生宏观裂纹;抗拉强度、屈服强度和伸长率均先升高后降低,Ti含量在0.2%~0.5%范围内,力学性能最好。综合分析表明,Ti含量在0.2%~0.5%范围内,Al-7%Mg合金的流动性、热裂性和力学性能良好,有利于形状复杂和有特殊要求的零件成形。
Microstructure and properties of cast Al-7%Mg （mass fraction） alloy with different Ti contents were investigated by fluidity, hot crack and mechanical properties testing, combining with Optical Microscope （OM）, Differential Scanning Calorimetry （DSC）, Phase Diagram and Scanning Electron Microscope （SEM）. The results show that grains of cast Al-7%Mg alloy are refined and equiaxed by adding Ti contents, with clear grain boundaries and increasing eutectic structures. Fluidity improves firstly and then reduces while hot tearing tendency decreases obviously with the increase of Ti contents. As a result, average flow length of the alloy with 0.2% Ti reaches 597 mm and the test samples do not present macroscopic crack when adding 0.5% Ti under experimental condition, respectively. Tensile strength, yield strength and elongation rate decrease after increasing first, and the best mechanical properties is obtained with Ti contents in the range of 0.2%-0.5%. Comprehensive analysis indicates that fluidity, hot crack and mechanical properties of cast Al-7%Mg alloy can achieve good condition with Ti contents in the range of 0.2%-0.5%, which contributes to the formation of components with complex shaoes and soeeial reauirements.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2015年第4期641-648,共8页
Materials Science and Engineering of Powder Metallurgy
基金
广州钢铁集团和广州金邦有色合金有限公司合作资助项目(20140001)
作者简介
通讯作者：杨昭，副教授，博士。电话：13487564482 E-mail：zyang@CSU．edu．cn
