FGH95粉末镍基合金的组织结构与蠕变断裂特征  

Microstructure and Creep Fracture Features of FGH95 Nickel-base Superalloy

作　　者：谢君[1] 田素贵[1] 周晓明[2] 汪武祥[2] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳1101782 [2]北京航空材料研究院,北京100095

出　　处：《材料工程》2009年第S2期147-151,156,共6页Journal of Materials Engineering

摘　　要：通过对不同工艺处理FGH95合金进行组织形貌观察及持久性能测试,研究了组织结构对合金持久性能的影响规律。结果表明:经1150℃固溶和时效处理后,合金中有粗大γ′相在较宽的边界区域不连续分布,其周围存在γ′相贫化区;经1160℃固溶及时效处理后,合金中粗大γ′相完全溶解,在晶内弥散分布高体积分数的γ′相,并有粒状(Cr,Nb)23(C,B)6硼碳化合物在晶内及沿晶界不连续析出;经1165℃固溶和时效后,合金的晶粒尺寸明显长大,并有硬而脆的碳化物膜沿晶界连续析出。在650℃、1034MPa条件下,经1160℃固溶和时效合金具有较高蠕变抗力和较长持久寿命,蠕变期间的变形机制是位错以Orowan机制饶过γ′相、或位错剪切γ′相,其中晶界处不连续析出的粒状碳化物可有效阻碍位错滑移,是使合金具有较好蠕变性能的主要原因。蠕变后期,合金的变形特征是晶内发生单取向滑移,随蠕变进行位错在晶界处塞积,并引起应力集中,致使裂纹在晶界处萌生及扩展是合金的蠕变断裂机制。By means of the enduring properties measurement and microstructure observation,an investigation has been made into the influence of the microstructure on the enduring properties of FGH95 nickel-base superalloy.The results shown that,after solution treated at 1150℃,the thicker γ' phase is distributed in the wider boundary regions between the grains,in which is a poor areas of the finer γ' phase.After solution temperature raised to 1160℃,the thicker γ' phase in the alloy is fully dissolved,and the fine γ' phase with high volume fraction is dispersedly distributed within the grains,thereinto,the particles of(Cr,Nb)23(C,B)6 carbide phase are uncontinuously precipitated along the boundaries.After solution treated at 1165℃,the grain sizes are obviously grown up,and the films of the carbide is continuously precipitated along the boundary.The deformed mechanisms of the alloy(treated at 1160℃)during creep are that the some dislocations are both over the γ' phase by Orowan mechanism and shearing into the γ' phase.Thereinto,the particles carbide which are discontinuously precipitated along the boundary can effectively hinder the dislocation motion,which results in the alloy possessing a better enduring properties under the applies stress of 1034 MPa at 650℃.In the later stage of creep,the deformed features of the alloy are that the single orientation slipping is activated.As creep goes on,some of the dislocations are piled up in the regions near the boundaries,this may bring out the stress concentration to promotes the budding and expanding of the micro-cracks,which is thought to be the fracture mechanism of the alloy during creep.

关 键 词：FGH95合金 组织形貌 持久性能 断裂特征 

分 类 号：TG146.15[一般工业技术—材料科学与工程]