Experimental and numerical study of the effects of porosity on fatigue crack initiation of HPDC magnesium AM60B alloy

被引：40

作者：

Lu, Y. ^{[2
]}

Taheri, F. ^{[1
]}

Gharghouri, M. A. ^{[3
]}

Han, H. P. ^{[4
]}

机构：

[1] Dalhousie Univ, Dept Civil Engn, Halifax, NS B3J 1Z1, Canada

[2] Dalhousie Univ, Mat Engn Programme, Halifax, NS B3J 1Z1, Canada

[3] Natl Res Council Canada, Canadian Neutron Beam Ctr, Chalk River Labs, Chalk River, ON K0J 1J0, Canada

[4] IMP Aerosp, Halifax, NS B2T 1L5, Canada

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2009年 / 470卷 / 1-2期

关键词：

Fatigue; Cast magnesium alloy; Porosity; Finite element simulation; HIGH-CYCLE FATIGUE; KINEMATIC HARDENING RULES; MINIMUM ENERGY FORMALISM; ALUMINUM-SILICON ALLOYS; SLIP BAND MODEL; AL-SI ALLOYS; CAST-ALUMINUM; RATCHETTING BEHAVIOR; NUCLEATION; PLASTICITY;

D O I：

10.1016/j.jallcom.2008.03.008

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In this study, high-cycle fatigue tests were conducted on specimens machined from 50 sequentially cast instrument panels made from high-pressure die-cast (HPDC) AM60B magnesium alloy. The fatigue life data were described by a two-para meter Weibull model. SEM analyses on the fracture surfaces showed the initiation of the fatigue cracks occurred exclusively at casting pores close to the machined surfaces. The dependence of local maximum plastic shear strain range on casting pore features and loading conditions was studied quantitatively by finite element simulation including varying the pore size, geometry and spacing, proximity to the free surface, as well as loading ratios. A constitutive plasticity model, the classic Ohno-Wang's kinematic hardening rule, was employed to simulate the isothermal monotonic and cyclic behaviour of magnesium AM60B alloy under uniaxial loading. The simulation results illuminated the microstructure-property relations for fatigue crack incubation and the resultant scatter in fatigue life. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：202 / 213

页数：12

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