CAJ | 학술논문

粉末冶金(P/M)合金中由于原始颗粒边界(PPB)的存在,在力学性能试样断口上呈现颗粒间断裂.通过SEM、TEM、AES 等手段对采用等离子旋转电极(PREP)制粉+直接热等静压(HIP)成形工艺的一种 P/M 镍基高温合金低周疲劳(LCF)断口上颗粒间断裂的形貌和类型进行了表征和分析,讨论了 PPB 的起因及其与疲劳裂纹在颗粒间萌生、扩展断裂机制的关系和颗粒间断裂对疲劳寿命的影响.结果表明:PREP+HIP 工艺成形的镍基合金中的 PPB 由多种综合因素造成;PPB 降低了合金的断裂韧性,直接影响颗粒间断裂程度;在 LCF 断口上,单颗粒成为裂纹源的占颗粒间断裂断口总数的67%,多颗粒裂纹源占17%,其他占16%;颗粒间断裂在 LCF 断口上的分布表征分为4级;颗粒间断裂越严重,对合金疲劳寿命影响越大.
분말야금(P/M)합금중유우원시과립변계(PPB)적존재,재역학성능시양단구상정현과립간단렬.통과SEM、TEM、AES 등수단대채용등리자선전전겁(PREP)제분+직접열등정압(HIP)성형공예적일충 P/M 얼기고온합금저주피로(LCF)단구상과립간단렬적형모화류형진행료표정화분석,토론료 PPB 적기인급기여피로렬문재과립간맹생、확전단렬궤제적관계화과립간단렬대피로수명적영향.결과표명:PREP+HIP 공예성형적얼기합금중적 PPB 유다충종합인소조성;PPB 강저료합금적단렬인성,직접영향과립간단렬정도;재 LCF 단구상,단과립성위렬문원적점과립간단렬단구총수적67%,다과립렬문원점17%,기타점16%;과립간단렬재 LCF 단구상적분포표정분위4급;과립간단렬월엄중,대합금피로수명영향월대.
@@@@The mechanical property of sample fractures shows inter-particle ruptures due to the existence of prior particle boundary (PPB) in P/M superalloys. The inter-particle rupture morphological characterization and type on low cycle fatigue (LCF) fracture of a nickel-based P/M superalloys by plasma rotating electrode process (PREP) plus hot isostatic press (as-HIP) were analyzed by SEM, TEM and AES. The causes of PPB formation and relationships between PPB and mechanism of fatigue crack initiation and crack propagation at inter-particle, as well as the effect of inter-particle rupture on LCF life, were discussed. The results show that PPB in P/M nickel-based superalloys processed by PREP +HIP is caused by many composite factors, PPB reduces the fracture toughness, and directly affects the degree of inter-particle rupture, a single particle to be the crack origin on LCF fracture accounts for 67% of the total fractures, multi-particle 17%, other 16%. The distribution characterization of inter-particle fracture on LCF fractograph can be divided into four grades, the more serious inter-particle fractures affects fatigue lives more.