Hf和Zr对FGH96合金PPB及力学性能的作用研究

The influence of Hf and Zr on PPB and properties of FGH96

采用PREP(等离子旋转电极法)制粉+HIP(热等静压)成形工艺制备FGH96合金,研究了w(Hf)+w(Zr)分别为0.0+0.04%、0.3%+0.04%、0.6%+0.04%和0.3%+0.06%时合金的显微组织,以及室温和800℃冲击性能,室温、650℃和750℃拉伸性能,650℃/970MPa持久性能。结果表明:FGH96合金的PPB未形成连续的网膜结构,对合金性能危害较小;适量的Hf可消除PPB组织,改善合金的高温性能,尤其能显著提高持久寿命和塑性,消除缺口敏感性;含Hf时,过量的Zr促使氧化物在粉末边界连续析出,严重降低合金持久性能。FGH96合金中,Hf、Zr的最佳含量为0.6%、0.04%。

FGH96 superalloy produced by PERP ＋ HIP with various Hf and Zr contents was studied in this paper. The Hf,Zramountwas designed as0.0＋0.04%, 0.3% ＋0.04%, 0.6% ＋0.04% and0.3% ＋0.06%. Optical microscope（OM） and second electricon microscope（SEM） were employed to investigate microstructures and fracture surfaces. The tested mechanical properties were listed as follows： room temperature（RT） and 800℃ impact, RT, 650℃ and 750℃ tensile, and 650℃/970MPa unnotched/notched（R = 0. 15mm） stress rupture. The results show that precipitations at PPB of FGH96 alloy can not form continuous films and hardly has destructive effects to the alloy. PPB are eliminated, elevated temperature properties are improved as well as stress rupture life and plasticity are especially enhanced with appropriate amount of Hf. While the alloy includes Hf, excess Zr lead to a continuous oxdie precipitations along the PPB, which severely degrade its endurance property. The optimum content of Hf, Zr in FGH96 alloy is 0. 6%,0. 04%.