摘要
采用冷热循环热处理工艺(改变的T7热处理工艺)来调整2A12铝合金显微组织从而提高其材料的尺寸稳定性。结果表明:该热处理方法与常见T6工艺、T4工艺对比,其铝合金的抗拉强度、屈服强度、微屈服强度都明显高于T6工艺15%,更优于T4工艺。显微组织观察表明:经过深冷循环处理的铝合金材料的体积收缩使得材料内部产生了大量的位错和亚晶等,铝合金晶粒没有明显再结晶回复,同时强化相已完全转化为S’相,相比T6工艺析出相析出更完全、分布更加均匀,从而提高其各种力学性能和尺寸稳定性。采用无负载条件下测试尺寸稳定性的结果表示:在相同条件下,T7工艺下比T4工艺下的尺寸稳定性提高了30%。
Influence of heat treatment process of T4,T6 and cryogenic-thermal cycling treatment after solution treating(modified T7) on microstructure,properties and dimensional stability of a 2A12 aluminum alloy was investigated.The results show that compared with the normal heat treatments T6 and T4,the tensile strength,yield strength and microyield strength of the aluminum alloy come a long way by T7,15% higher than T6,and much more than T4.The microstructure shows that after treated by the thermal cycle test(T7),no significant recovery and recrystallization process are observed in 2A12 aluminum alloys.The grains deflected and the new orientations blocked the dislocation slip.The laves transformed to S' phase entirely.Compared with T6,the mechanical properties and dimensional stability are raised because of the laves under T7 are completely precipitated and uniformly distributed.The dimensional stability tested results show that the dimensional stability of 2A12 aluminum alloy treated by T7 is 30% higher than T4.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第S1期41-45,共5页
Transactions of Materials and Heat Treatment
基金
辽宁石油化工大学校科研创新基金(2011-XJJ-014)
关键词
铝合金
冷热循环热处理
显微组织
尺寸稳定性
aluminum alloy
thermocycling heat treatment
microstructure
dimensional stability
