PPB对镍基粉末高温合金裂纹扩展行为的影响  

Influence of PPB on Crack Growth Behavior of PM Ni-Based Superalloy

作　　者：张莹[1] 张义文[1] 孙志坤[1] 黄虎豹[1] Zhang Ying;Zhang Yiwen;Sun Zhikun;Huang Hubao(Beijing CISRI-Gaona Materials&Technology Co.Ltd,Central Iron&Steel Research Institute,Beijing 100081,China)

机构地区：[1]钢铁研究总院北京钢研高纳科技股份有限公司

出　　处：《稀有金属材料与工程》2019年第10期3282-3288,共7页Rare Metal Materials and Engineering

基　　金：国家科技重大专项(2017-VI-0008-0078);国家国际科技合作专项(2014DFR50330)

摘　　要：研究了直接热等静压(As-HIP)成形的一种镍基粉末高温合金中原始颗粒边界(PPB)对其裂纹扩展行为的影响。结果表明,粉末高温合金中的原始颗粒边界上析出的碳化物、氧化物会导致断裂韧性(KIC值)降低,使界面极易萌生裂纹;在裂纹扩展过程中发生沿颗粒间断裂,改变扩展棱的走向,并加剧裂纹沿晶界扩展,使裂纹扩展速率加快;沿原始颗粒边界扩展的裂纹尖端的断裂韧度与边界析出物的物理性质、数量、尺寸密切相关,析出物排列越密集,KIC值越小,会加速裂纹在这些薄弱区扩展。The effect of prior particle boundary(PPB) on the crack growth behavior of a powder metallurgy nickel-based superalloy formed by direct hot isostatic pressing(As-HIP) was investigated.The results show that the precipitated carbide and oxide on the boundary of prior particles in the powder metallurgy superalloy decrease the fracture toughness(KIC) and initiate cracks from the interface easily.In the course of crack propagation,fractures occur along the inter-particles,which changes the direction of extended edges,aggravates the propagation of cracks along the grain boundaries,and thus increases the crack growth rate.The fracture toughness of the crack tip extending along the boundary of prior particle is closely related to the physical properties,amount and size of the precipitates on the PPB.The denser the precipitates,the smaller the KIC,and the crack propagation is accelerated in these weak areas.

关 键 词：镍基粉末高温合金 裂纹扩展速率 颗粒间断裂 原始粉末颗粒边界(PPB) 断裂韧性 

分 类 号：TF124[冶金工程—粉末冶金] TG146.15[冶金工程—冶金物理化学]