中国激光, 2018, 45 (11): 1102004, 网络出版: 2018-11-15
热处理对激光立体成形DZ125高温合金组织的影响 下载: 606次
Effect of Heat Treatment on Microstructure of Laser Solid Formed DZ125 Superalloy
激光技术 激光立体成形 定向凝固 高温合金 显微组织 热处理 laser technique laser solid forming directional solidification superalloy microstructure heat treatment
摘要
研究了热处理对激光立体成形DZ125高温合金凝固微观组织的影响。结果表明,随着固溶处理温度的升高,初生γ′相的溶解增多,在1240 ℃固溶2 h后初生γ′相全部固溶;Ni5Hf相和MC(1)碳化物在高温保温时发生固态相变,经1180 ℃/2 h/空冷(AC)热处理后Ni5Hf相全部分解,释放的Hf元素与基体固溶的C原子结合形成MC(2)碳化物,部分MC(1)碳化物在1000 ℃保温12 h后转变为M23C6或M6C型碳化物;完全固溶处理后在1100 ℃和870 ℃时效时,γ′颗粒尺寸的变化规律及经验分布函数与Lifshitz-Slyozov-Wagner(LSW)理论预测的较为一致。拟合得到γ′相的粗化激活能为231.43 kJ/mol,γ′颗粒的粗化受Ti、Al原子在Ni中的扩散控制。
Abstract
The effect of heat treatment on the solidification microstructure of the laser solid formed DZ125 superalloy is investigated. The results show that, with the increase of solution treatment temperature, the more primary γ′ particles are dissolved and these particles can be completely dissolved after treatment at 1240 ℃ for 2 h. There occurs solid-state phase transition for the Ni5Hf phase and MC(1) carbides at high-temperature insulation. When treated at 1180 ℃ for 2 h, the Ni5Hf phase can be completely decomposed and the released Hf subsequently reacts with C atoms in solid solution matrix to form MC(2) carbides. Some MC(1) carbides transform into M23C6 or M6C carbides when maintained at 1000 ℃ for 12 h. The coarsening behavior and the empirical distribution function of the γ′ phase are consistent with those given by the Lifshitz-Slyozov-Wagner (LSW) theory when aged at 1100 ℃ and 870 ℃ after the complete solution heat treatment. The fitted coarsening activation energy of the γ′ phase is 231.43 kJ·mol-1 and the coarsening of γ′ particles is controlled by the diffusion of Al and Ti species in Ni.
杨海欧, 韩加军, 林鑫, 黄卫东. 热处理对激光立体成形DZ125高温合金组织的影响[J]. 中国激光, 2018, 45(11): 1102004. Yang Haiou, Han Jiajun, Lin Xin, Huang Weidong. Effect of Heat Treatment on Microstructure of Laser Solid Formed DZ125 Superalloy[J]. Chinese Journal of Lasers, 2018, 45(11): 1102004.