FGH4096粉末高温合金保载低周疲劳性能研究  

Study on Sustained Peak Low-Cycle Fatigue Performance of PM FGH4096 Superalloy

作　　者：鲁亮 张剑锋 徐瑶 杨璟 LU Liang;ZHANG Jianfeng;XU Yao;YANG Jing(AECC Commercial Aircraft Engine Co.,Ltd.,Shanghai 200241,China)

机构地区：[1]中国航发商用航空发动机有限责任公司,上海200241

出　　处：《航空制造技术》2024年第12期44-50,共7页Aeronautical Manufacturing Technology

基　　金：国家自然科学基金(52105163)。

摘　　要：对FGH4096粉末高温合金在700℃下进行了总应变范围控制的低周疲劳试验和拉伸应变保载低周疲劳试验,研究了保载时间对滞回环特征、应力松弛、循环应力响应和疲劳寿命的影响及其产生作用的损伤机理。结果表明,保载时间的引入可导致FGH4096合金疲劳寿命降低,随保载时间的延长,疲劳寿命降低速率逐渐减小;在总应变范围0.9%下,不同保载时间下FGH96合金均表现出循环软化特征;在拉伸应变保持期间发生应力松弛现象,拉伸应变保持初始阶段,应力急剧下降,之后随保持时间延长而趋于平缓。微观组织分析表明,低周疲劳断口和保载低周疲劳断口均由疲劳源区、疲劳裂纹扩展区和瞬断区组成,疲劳源区均位于试样表面,扫描电镜下观察两种试样断口均未发现明显的蠕变断裂特征。Total strain-controlled low-cycle fatigue tests and sustained peak low-cycle fatigue tests with load-holding at maximum tension strains were conducted on powder metallurgy(PM)FGH4096 superalloy at 700℃.The influence of the dwell time on the hysteresis loops,stress relaxation,cyclic stress response,fatigue life and damage mechanism were discussed.As shown in test results,tensile strain holding reduce fatigue life.PM FGH4096 superalloy exhibits cyclic softening with different dwell time at the total strain range of 0.9%.The saturation phenomenon of holding effect is found when dwell time increases.Stress relaxation and creep deformation occur during the tensile strain holding period.The stress decreases sharply in the first few seconds of the tensile strain holding period and much slowly later.The low-cycle fatigue fracture and sustained peak low-cycle fatigue fracture are composed of fatigue source area,fatigue crack propagation area and instantaneous fracture area.The fatigue source area is located on the specimen surface.No obvious creep fracture characteristics are found in sustained peak low-cycle fatigue fracture and low-cycle fatigue fracture.

关 键 词：FGH4096 粉末高温合金 保载低周疲劳 应力松弛 拉伸应变 疲劳断口 

分 类 号：TG132.3[一般工业技术—材料科学与工程]