Microstructure and Properties of Ti and Sc Microalloyed Aluminum Alloys
Author of the article:CHEN Hua;YU Aiwu;YE Qing;QI Haiyan;SHI Xiangling;YANG Chenggang;SHI Lei;PI Gang
Author's Workplace：Shanghai Aerospace Equipments Manufacturer Co.,Ltd.,Shanghai 200245,,China;Nanchang Hangkong University,Nan-chang 330063,China
Key Words：microstructure mechanical properties solid solution strengthening composite strengthening phase heterogeneous nucleating core
Abstract：The effects of Ti and Sc microalloying on the microstructure and mechanical properties of industrial pure aluminum were investigated by adding microelements Ti and Sc or in combination to industrial pure aluminum. The results show that the grain refinement effect of 0.2% Sc is not ideal,but the strength and hardness of the alloy can be improved effectively,while the elongation is slightly reduced by the solid solution strengthening effect of Sc element. While 0.2% Ti has a good grain refining effect,the microstructure of the alloy is completely transformed into equiaxed grains,and the strength and plasticity of the alloy are significantly improved,but the hardness is not significantly changed. The average grain size of the alloy is only about 80 μm,and the strength,elongation and hardness of the alloy are the best. The eutectic point of Al-Sc can be reduced by Ti/Sc composite microalloying. The Al3( Sc,Ti) composite strengthening phase can be formed by Ti instead of some Sc in Al3 Sc,which can be used as the heterogeneous nucleating core of α( Al),so as to refine the microstructure and strengthen the Al alloy.
