先进镍基高温合金疲劳损伤的微观机制  

Microscopic Mechanism of Fatigue Damage for Advanced Nickel-base Superalloys

作　　者：刘新灵[1,2] 陶春虎[1,2] 刘德林[1,2] 

机构地区：[1]北京航空材料研究院,北京100095 [2]航空材料检测与评价北京市重点实验室,北京100095

出　　处：《稀有金属材料与工程》2015年第12期3178-3182,共5页Rare Metal Materials and Engineering

基　　金：国家高技术研究发展计划("863"计划)(2015AA034401)

摘　　要：通过对FGH96粉末高温合金、DZ125定向凝固高温合金、DD6单晶高温合金大量疲劳断口的断裂特征进行统计分析,研究了这3类镍基高温合金疲劳损伤的微观机制。结果表明,这3类合金疲劳断裂的宏观形貌有较大的区别,但由于这几类合金均为镍基面心立方晶体结构,因此其疲劳损伤断裂具有相同的微观演变规律和断裂机制,即:从疲劳裂纹的萌生至裂纹的快速扩展均是以滑移机制进行;疲劳扩展第1阶段均为类解理特征,疲劳扩展第2阶段为疲劳条带,快速扩展区呈现为滑移面、滑移台阶、韧窝特征。由于其组织和成形工艺的区别,其共同的特征表现的具体形貌有所区别。Statistical analysis of fatigue fracture surfaces for FGH 96 powder metallurgical superalloy, DZ125 directionally solidified superalloy and DD6 single crystal superalloy has been developed and the microscopic mechanism of fatigue damage for these alloys was also investigated. The results show that for the three kinds of superalloy, there are obvious differences for macro-fracture morphologies; however, the micro-fracture characteristics and failure mechanism are consistent because of the same nickel-base face centered cubic lattice. Slipping mechanism dominates the crack initiation, steady propagating and fast propagating. Cleavage-like characteristic is in the first fatigue phase, fatigue striation characteristic is in the second fatigue phase, while slipping faces, slipping steps and dimples are in the instantaneous area. The frondose aspects are different on the basis of common characteristics because of different material structures and techniques for different superalloys.

关 键 词：粉末高温合金 定向凝固高温合金 单晶高温合金 疲劳断裂 失效机制 

分 类 号：TG132.3[一般工业技术—材料科学与工程]