Identification and modeling of fatigue crack growth mechanisms in a die-cast AM50 magnesium alloy

被引：55

作者：

El Kadiri, Haitham ^{[1
]}

Xue, Ybin ^{[1
]}

Horstemeyer, M. F. ^{[1
]}

Jordon, J. Brian ^{[1
]}

Wang, Paul T. ^{[1
]}

机构：

[1] Mississippi State Univ, Ctr Adv Veh Syst, Mississippi State, MS 39762 USA

来源：

ACTA MATERIALIA | 2006年 / 54卷 / 19期

关键词：

fatigue; fractography; microstructure; chemical analyses; multistage modeling;

D O I：

10.1016/j.actamat.2006.06.039

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We experimentally identified the fatigue crack growth micromechanisms operating near the limit plasticity regime in a commercial high-pressure die-cast AM50 alloy with a critical review of the available literature. An existing multistage fatigue model was modified to subsequently recognize these micromechanisms in a threefold fatigue crack growth regime. The formation of the main fatigue crack occurred almost exclusively at shrinkage pores and to a lesser extent at large Mn-rich particles. At shrinkage pores, several adjacent cracks typically incubated at the edge of flat interdendritic pores, propagated along the ot-Mg dendrite cells/Al-rich eutectic interface, and rapidly coalesced into a main physically small fatigue crack that advanced through the Al-rich eutectic. In the long crack regime, the crack advanced in a mixed transdendritic-interdendritic mode along persistent slip bands spreading over several tens of dendrite cells. The model predicts well the fatigue life compared to the experimental data when these observed mechanisms are accounted for. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

引用

页码：5061 / 5076

页数：16

共 26 条

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