大块金属玻璃非晶形成能力表征参数探讨

An Approach to Characteristic Parameters of GFA of BMG Based on the Statistics

把大块金属玻璃合金系作为一物质系统 ,利用加和性原则分别计算其物理结构参数 ,即混合熵Smix、摩尔原子半径差εd、摩尔原子电负性差εe、热扩散率α以及熔点与熔化焓之比Tm/Hm等 ,分别把大块金属玻璃的临界冷却速度Rc、最大尺寸Zmax以及Zmax/Rc作为合金玻璃形成能力的目标 ,用Origin6.1软件分别对εd·εe·α·Smix·Tm/Hm(记做Л)和Rc,Zmax及Zmax/Rc做统计图。结果表明 :如果以Rc作为合金玻璃形成能力的目标 ,Л为 0 .0 2～ 0 .175时合金的玻璃形成能力最好 ;如果以Zmax作为合金玻璃形成能力的目标 ,Л为 0 .0 47～ 0 .15时合金的玻璃形成能力最好 ;如果以Zmax/Rc作为合金玻璃形成能力的目标 ,Л为 0 .0 3～ 0 .15时合金的玻璃形成能力最好。综合的最佳范围为 0 .0 47～ 0 .15。

Taking the BMG series as a material system, the physi ca l and structural parameters of the BMG were separately calculated by the additio nal principle, including mixed entropy S mix , mole atomic radius differ ence εd, mole atomic electronic difference εe, thermal diffusion ratio α and ratio (T m/H m) of melting point temperature T m and me lting enthalpy H m. R c(critical cooling velocity), Z max ( maximum size) and Z max /R c for BMG were considered as the targe t of glass forming abil ity respectively. The statistic figures ε d·ε e ·α·S mix ·T m/H m (denoted by Л): R c,-Л, Z max -Л ,Z max /R c-Л have been drawn by Origin 6.1 software. The re sults showed that the optimum GFA for Л=0.020～0.175, for Л=0.047～0.1 50 and for Л=0.03～0.15 when R c,Z max and Z max /R c as were taken as the target respectively. The range of c omprehensive optimum Л is 0.047～0.15. It was concuded that the Л was an ideal new paramete r to characterise the glass forming ability of the BMG.