微量钪对Al-2．5Cu-1．5Mg合金时效特性与微观组织的影响

Role of Minor Sc Addition on Ageing Characteristics and Microstructure in Al-2.5Cu-1.5Mg Alloy

摘要:

研究了微量钪对Al-2．5Cu-1．5Mg合金微观组织与时效特性的影响。结果表明，微量钪的添加增强了Al-2．5Cu-1．5Mg合金的时效硬化效果，但并未改变该合金时效硬化的总体规律。透射电镜分析发现GPB在合金时效硬化第二阶段初期才开始析出，并且是该合金第二阶段硬化的主要原因，微量钪的添加促进了Al-2．5Cu-1．5Mg合金中GPB的弥散细小析出。

Abstract:

The effects of small addition of scandium on the microstructure and ageing characteristics in Al-2.5Cu-1.5Mg alloys have been investigated. The results indicate that the age hardening response of the Al-2.5Cu-1.5Mg alloy can be enhanced while the general form of the ageing curve is not altered by small addition of Sc. TEM observations show that GPB can only precipitated during the second age hardening period which will make a great contribution to the age hardening, and the morphology of GPB can be modified by the small addition of Sc, which does result in a refinement of the distribution of GPB in Al-2.5Cu-1.5Mg-0.2Sc.