钕对4004铝合金变质效果的影响

Effect of Nd on Modification of 4004 Aluminum Alloy

研究了在熔体温度为720℃保温时间为60min时稀土钕加入量（0%、0.15%、0.30%、0.45%和0.60%）对4004铝合金变质效果的影响。结果表明：当钕加入量低于0.30%时,合金组织和力学性能都没有达到完全变质的状态;当钕加入量为0.30%时,4004铝合金变质效果最好,合金组织中的初晶铝转变为细小的圆状或短棒状,共晶硅也由片状或针状转变为纤维状,合金的抗拉强度达到最大值（197MPa）,伸长率也达到最大值（4%）;当加入量超过0.30%时,随着加入量的增加,合金的组织开始变得粗大,抗拉强度和伸长率随之降低。

The effect of different amount of Nd（0%,0.15%,0.30%,0.45% and 0.60%） on the modification of 4004 aluminum alloy was studied when the melt temperature was set at 720 ℃ and holding time was 60 min.The results show that,when the amount of Nd is less than 0.30%,the microstructure and mechanical properties of the alloy reach uncomplete modification;when Nd addition is 0.30%,the alloy reaches the best modification state,the primary aluminum transforms into small round or short rod-like,chip or needle-like eutectic silicon transforms into fibrous and the tensile strength reaches the maximum（197 MPa）,the elongation also reaches the maximum（4%）;when more than 0.30% Nd,with the increase of Nd addition,the microstructure of the alloy is coarsened,the tensile strength and elongation of the alloy reduce.