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

Rare earth elements are important additives for improving the forming ability and performance of amorphous alloys. In this paper, a series of Cu_(50 - x)Zr_(46)Al_4RE_x (RE = Dy, Tb, Gd; x = 0, 1, 2, 3, 4) amorphous alloys were prepared by copper mold suction casting method, and the effects of the addition of heavy rare earth elements Dy, Tb, Gd on the glass-forming ability (GFA) and mechanical properties of Cu - Zr - Al alloys were systematically investigated. The experimental results show that after the addition of heavy rare earth elements Dy, Tb, Gd, the glass transition temperature of the alloy system is significantly decreased, while the width of the supercooled liquid region ΔT_x (ΔT_x = T_x - T_g) is increased. The addition of 1% (atomic fraction) of Dy, Tb and 3% (atomic fraction) of Gd obtains the maximum γ = T_x/(T_g + T_l) parameter value, indicating that an appropriate amount of addition is beneficial to the improvement of the alloy's glass-forming ability. At the same time, the appropriate introduction of Dy, Tb, Gd can significantly improve the plastic deformation ability of the Cu - Zr - Al alloy. The hardness and γ parameter show a similar changing trend with the change of the content of rare earth elements, indicating that there is a certain correlation between the glass-forming ability and hardness. The addition of rare earth elements leads to a greater radial inhomogeneity of the hardness of the amorphous alloy samples, which is beneficial to the improvement of the alloy's plastic deformation ability.

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_4RE_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+T_l)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。