FGH95镍基合金组织结构对持久性能的影响

通过对不同温度热等静压FGH95合金进行完全热处理、组织形貌观察、XRD谱线分析及持久性能测试,研究FGH95合金组织结构对持久性能的影响。结果表明:随着HIP温度升高,分布在原始颗粒边界处的粗大γ′相数量和尺寸逐渐减小,当HIP温度提高至1 180℃,晶粒明显长大。热等静压合金经完全热处理后,粒状碳化物沿晶界和晶内不连续分布,且细小γ′相在基体中弥散析出。经X线衍射分析,随热等静压温度升高,γ和γ′两相晶格常数略有增加,但错配度逐渐减小;在650℃,1 034 MPa条件下,由于1 120℃HIP合金完全热处理后具有较高的晶格错配度,致使合金具有较长持久寿命;合金在蠕变期间的变形特征是位错滑移,位错绕过或剪切γ′相。

Influence of microstructure on enduring properties of FGH95 nickel-base superalloy

By means of full heat treatment,microstructure observation,XRD diffraction analysis and enduring properties measurement,an investigation was made into the influence of microstructure on enduring properties of FGH95 superalloys.The results show that the quantities and size of the coarser γ phase distribute in the regions decrease as the HIP temperature increases.With the HIP temperature increases to 1 180 ℃,the grain obviously grows up.After the HIP alloy is fully heat treated,the carbide particles discontinuously distribute along boundaries and in the grain,and the fine γ phase dispersedly precipitates in the matrix.After X-ray diffraction analysis,the lattice parameters of γ and γ phase increase slightly,but the misfit decreases gradually.Under the condition of 650 ℃ and 1 034 MPa,as the 1 120 ℃ HIP alloy which is fully heat treated has higher lattice misfit,the alloy possesses longer lifetime.During creep process,the deforming features of the alloy are dislocations slipping in the matrix,dislocations crossing or shearing into γ phase.