Au-Cu-Al合金相变的内耗

利用内耗方法分别对淬火态和时效态Au7Cu5Al4合金的相变过程进行了研究，分析了2种状态马氏体相变的差异.结果表明：淬火态与时效态Au7Cu5Al4合金的马氏体相变开始温度分别为-2.7和13.8 °C;根据驰豫内耗峰信息得出其晶界驰豫激活能分别为131.5和93.0 kJ/mol，反映了时效前后Au7Cu5Al4合金有序度的差异，即淬火态Au7Cu5Al4合金母相在室温下主要为B2结构，而时效态合金为L21有序结构.

Internal Friction Analysis of Transformations in Au-Cu-Al Alloy

The phase transformation in the as quenched and aged Au7Cu5Al4 alloys were investigated by internal friction technique. The results show that Ms temperatures of the as quenched and aged Au7Cu5Al4 alloys are -2.7 °C and 13.8 °C, respectively. The boundary relaxation activation energy for the quenched and aged Au7Cu5Al4 alloys were calculated for 131.5 kJ/mol and 93.0 kJ/mol, respectively, which indicates the difference of ordering states of the parent phases resulted by different thermal history. By high temperature internal friction measurement it is found that the B2→L21 ordering transition is interrupted by quenching and the parent phase state of quenched Au7Cu5Al4 alloy shows B2 ordering, which suppresses martensitic transformation.