应力时效对DD11单晶高温合金TCP相析出行为的影响

Effects of Stressed Aging on TCP Phase Precipitation Behaviour of DD11 Single Crystal Superalloy

摘要: 对完全热处理后的DD11镍基单晶高温合金分别进行了1 070 ℃、100 MPa应力时效和1 070 ℃无应力时效处理，分析了不同条件时效后拓扑密堆（TCP）相的析出行为。结果表明：在应力时效和无应力时效50 h后，试验合金中均未析出TCP相，时效至100 h时，在枝晶干区域均开始析出TCP相，且析出量随时效时间的延长而增加；在相同的时效时间内，应力时效后TCP相的析出量比无应力时效后的少，应力没有改变TCP相的化学成分和晶体结构，析出的TCP相均为μ相。

Abstract: After a completely heat treatment, DD11 nickel-based single crystal superalloy was treated by stressed aging at 1 070℃ under 100 MPa and unstressed aging at 1 070℃, respectively. The precipitation behaviour of topologically close-packed (TCP) phase after aging under different conditions was analyzed. The results show that no TCP phase precipitated in the tested alloy after stressed aging and unstressed aging for 50 h. After aging for 100 h, TCP phase began to precipitate in dendrite region; the precipitation amount of TCP phase increased with the extension of aging time. For the same aging time, the precipitation amount of TCP phase after stressed aging was less than that after unstressed aging. The stress did not change chemical composition and crystal structure of TCP phase; the precipitated TCP phase was μ phase.