二元合金过冷液态的形核驱动力和非晶形成能力的热力学分析

DRIVING FORCE FOR THE NUCLEATION FROM SUPERCOOLED LIQUID AND THERMODYNAMIC ANALYSIS OF GLASS FORMING ABILITY FOR BINARY ALLOYS

利用CALPHAD(calculation of phase diagrams)技术和已有热力学数据,通过对比分析亚稳过冷液态合金中各结晶相的形核驱动力大小,寻找结晶能力弱而非晶形成能力强的成分范围.选择典型的非晶形成体系,以平衡卡相图中共晶深度明显不同的3个二元合金体系Cu-Zr,Ni-Nb和Pd-Si为研究对象,预测各体系非晶形成能力与成分的关系,获得非品形成最优成分,并与共晶点成分及实验数据进行对比.预测结果与实验确定的块体非晶最优成分相符.

Using CALPHAD （calculation of phase diagrams） technique and the reported thermodynamic parameters, the driving forces for the formations of all crystalline phases from supercooled liquid states were analyzed, and the composition ranges with low crystalline abilities but high glass forming abilities （GFA） were estimated thermodynamically for glass forming systems. The typical glass forming binary systems, Cu Zr, Ni Nb and Pd-Si, were selected and investigated, in which the eutectic depths in the equilibrium phase diagrams are visibly different. The compositional dependency of GFA was predicted in each alloy system, the best glass formers were obtained and compared with the eutectic points and the experimental results. The present estimation fit the experimental results well.