重稀土元素添加对Cu-Zr-Al合金非晶形成和力学性能的调控

Effect of heavy rare earth elements addition on the glass forming and mechanical properties of Cu50Zr46Al4 alloy

稀土元素是改善非晶态合金形成能力和性能的重要添加剂,本文采用铜模吸铸法制备了一系列Cu_(50-x)Zr_(46)Al_(4)RE_(x)(RE=Dy,Tb,Gd;x=0,1,2,3,4)非晶态合金,系统地探究了重稀土元素Dy、Tb、Gd添加对Cu-Zr-Al合金非晶形成能力(GFA)和力学性能的影响。实验结果表明加入重稀土元素Dy、Tb、Gd后,合金系的玻璃转变温度显著降低,而过冷液相区宽度ΔT_(x)(ΔT_(x)=T_(x)-T_(g))增大,1%(原子分数)的Dy、Tb和3%(原子分数)的Gd添加获得了最大的γ=T_(x)/(T_(g)+Tl)参数值,表明合适的添加量有利于合金非晶形成能力的提高。同时,适量的Dy、Tb、Gd引入可以显著提高Cu-Zr-Al合金的塑性变形能力。硬度和γ参数随稀土元素含量的变化呈现相似的变化趋势,表明非晶形成能力与硬度之间存在一定的关联性。稀土元素添加导致非晶态合金样品硬度呈现更大的径向不均匀性,有利于合金塑性变形能力的提高。

Rare earth elements are important additives to improve the forming ability and properties of amorphous alloys.A series of Cu_(50-x)Zr_(46)Al_(4)RE_(x)(RE=Dy,Tb,Gd;x=0,1,2,3,4)amorphous alloys are prepared by copper mold suction casting method.The effects of Dy,Tb,and Gd on the glass forming ability(GFA)and mechanical properties of Cu_(50)Zr_(46)Al_(4) alloys are systematically investigated.The experimental results show that with the addition of Dy,Tb,and Gd,the glass transition temperature of the alloy system decreases significantly,while the width of supercooled liquid regionΔT_(x) increases.The maximum value ofγparameter is obtained by adding 1at%Dy,Tb,and 3at%Gd,which indicates that the appropriate addition amount is beneficial to the improvement of glass forming ability.At the same time,the plastic deformation ability of Cu-Zr-Al alloy can be improved by adding proper amount of Dy,Tb and Gd.The results show that there is a close relationship between the glass forming ability and the hardness.The addition of rare earth elements leads to a greater radial inhomogeneity in the hardness of the alloy samples,which is conducive to the improvement of the plastic deformation ability of the alloy.