非晶合金晶化曲线的研究

Research on Crystallization Start Diagram for Amorphous Alloy

采用静置激光点热源重熔技术,对非晶合金重熔后的晶化特征进行分析。结果表明,热影响区(HAZ)的晶化趋势大于熔化区(MZ),在热影响区和母材的交界位置,合金处于即将晶化而又未晶化的临界状态,晶化曲线与临界位置的热循环曲线相切。根据相切原理,通过数值模拟不同重熔条件下临界位置的热循环曲线,建立了用于直观预测焊接工艺参数的非晶合金Zr48Cu45Al17晶化曲线。

A fixed laser spot heat source, which can heat and cool amorphous alloys at a high rate, was used to re-melt the amorphous alloy Zr48Cu45Al17. The analysis of crystallization characteristics indicates that the heated-affected zone （HAZ） is liable to crystallize more easily than the molten zone （MZ）, and at the boundary between the HAZ and the parent alloy there is a critical state between crystalline and amorphous state. Crystallization start diagram should be tangent with the thermal cycle of the critical location. Accordingly, the crystallization start diagram for amorphous alloy Zr48Cu45Al17 at high heating and cooling rate was determined with tangential points of the numerical simulated thermal cycles at the boundaries under different re-melting conditions.