基于成分连续变化计算黏度的合金系临界冷速模型

A new model for calculating critical cooling rates of alloy systems based on viscosity calculation

在大块非晶临界冷却速率的非等温转变计算模型基础上提出了基于成分连续变化计算黏度的合金系临界冷速模型.依据此模型对Zr_Ni_Al_Cu四元合金的临界冷却速率进行了计算并预测了Zr66.67(NixAlyCuz)33.33合金系中容易形成非晶的成分范围.计算值与实验值符合得较好.计算结果表明,此合金系具有很强的非晶形成能力,特别是在靠近共晶点的中心区域,临界冷却速率小于100K/s,为容易形成非晶的成分范围.冷却过程中,在高于1000K温度区间,没有发生明显的结晶现象,而在980K至870K温度范围内,结晶分数快速增大,低于870K时不再发生明显改变.此外,分析了合金系中Al,Cu,Ni原子摩尔分数的变化对临界冷速的影响.

Based on the model for calculating the critical cooling rate of bulk metallic glasses under non-isothermal condition, a new model for calculating the critical cooling rate of alloy systems based on viscosity calculation is put forward in this paper. The critical cooling rates of Zr-Ni-Al-Cu quaternary alloys were calculated and the glass forming range in Zr66.67 （NixAlyCuz ）33.33 quaternary alloy system is predicted. The results are in good agreement with the experimental values. The calculation results show that there is high glass forming ability in Zr66.67 （NixAlyCuz ）33.33 quaternary alloy system. The glass forming range is near eutectic point in which critical cooling rates are less than 100 K/s. There is not crystallization in the temperature range higher than 1000K, the fraction of crystals increases rapidly in the temperature range from 980 K to 870 K, and it is not changed in the temperature range below 870 K. In addition, the effects of Al, Cu, Ni mole fraction on the critical cooling rate are analyzed in this paper.