This is because that duplex aging results in more amounts of dispersing and homogeneously distributing hardening precipitates, and reduces the negative effect due to lower vacancy concentration.

• 这是因为相对单级时效而言双级时效可使慢速淬火合金中得到更多强化相，分布也更均匀弥散，从而减小空位浓度降低带来的不利影响；