Effects of Zr additions on structure and tensile properties of an Al-4.5Cu-0.3Mg-0.05Ti(wt.%) alloy  

作　　者：Hamed Kamali Erfan Kamali Massoud Emamy 

机构地区：[1]School of Metallurgy and Materials Engineering,College of Engineering,University of Tehran,P.O.Box 11155-4563,Tehran,Iran [2]Faculty of Materials Engineering,Sahand University of Technology,P.O.Box 51335-1996,Tabriz,Iran

出　　处：《China Foundry》2022年第1期9-16,共8页中国铸造（英文版）

摘　　要：The effects of different Zr additions(0.05wt.%-0.5wt.%)on the structure and tensile properties of an Al-4.5Cu-0.3Mg-0.05Ti(wt.%)alloy solidified under a high cooling rate(18℃·s^(-1)),in as-cast and T6 heat-treated conditions were studied.The as-cast structure of the alloy consists of equiaxed grains ofα-Al with an average size of 64μm which is unaffected by the Zr additions,indicating the ineffectiveness of Zr in the grain refinement of the alloy.Scanning electron microscopy,along with X-ray diffraction analysis revealed the presence of elongatedθ-Al2Cu at the grain boundaries;in addition,coarse Al3Zr particles exist in the intergranular regions of the 0.5wt.%Zr-containing alloy.After the T6 heat treatment,the elongatedθparticles were fragmented;however,the coarse Al3Zr particles remained unchanged in the microstructure.Also,the formation of fineβ’-Al3Zr andθ’’-Al3Cu/θ’-Al2Cu phases during T6 heat treatment was revealed by transmission electron microscopy.The results of the tensile tests showed that the Zr additions increase the strength of the alloy in both as-cast and T6 heat-treated conditions,but reduce its elongation,especially with 0.5wt.%Zr addition.The 0.3wt.%Zr-added alloy in the T6 heat-treated condition has the highest quality index value(249 MPa).Fractography of the fracture surfaces of the alloys revealed ductile fracture mode including dimples and cracked intermetallic phases in both conditions.

关 键 词：Al-Cu-Mg alloys CASTING T6 heat treatment STRUCTURE precipitation hardening tensile properties FRACTOGRAPHY 

分 类 号：TG146.21[一般工业技术—材料科学与工程]