The thickness of defect bands in high-pressure die castings

被引:56
作者
Otarawanna, S. [1 ]
Gourlay, C. M. [2 ]
Laukli, H. I. [3 ]
Dahle, A. K. [4 ]
机构
[1] Univ Queensland, CAST CRC, Brisbane, Qld 4072, Australia
[2] Univ London Imperial Coll Sci Technol & Med, Dept Mat, London SW7 2AZ, England
[3] Hydro Aluminium, Res & Technol Dev, N-6601 Sunndalsora, Norway
[4] Univ Queensland, ARC CoE Design Light Met, Brisbane, Qld 4072, Australia
基金
澳大利亚研究理事会;
关键词
High pressure die casting; Macrosegregation; Defect bands; Reynolds' dilatancy; Strain localization; EBSD; IN-SITU; SHEAR DEFORMATION; MG-AL; MICROSTRUCTURE; SOLIDIFICATION; FRAGMENTATION; AZ91;
D O I
10.1016/j.matchar.2009.06.016
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Defect bands following the casting contour are often observed in high-pressure die cast (HPDC) components. In this article, suitable methods for measuring the thickness (w) and grain size in the bands (d(sb)) in HPDCs have been developed. The w/d(sb) relationship of defect bands has been investigated in HPDC specimens from a range of alloys, casting geometries and band locations within castings. Samples include aluminum alloy, AlSi4MgMn and AlMg5Si2Mn, tensile test bars cast by cold-chamber (cc) HPDC and a magnesium alloy, AM50, hot-chamber (hc) HPDC steering-wheel component. The band thicknesses were measured to be in the range 7-18 mean grains wide. This is substantial evidence that defect bands form due to strain localization in partially solidified alloys during cc and hc HPDC. Additionally, within this range, the w/d(sb) ratio decreases with increasing distance from the casting center in a cross-section containing multiple bands. (C) 2009 Elsevier Inc. All rights reserved.
引用
收藏
页码:1432 / 1441
页数:10
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