Distribution of Mn- and Cr-containing dispersoids in Al-Mg-Si-alloys

被引：1

作者：

Lodgaard, Lars ^{[1
]}

Ryum, Nils ^{[1
]}

机构：

[1] Dept. Mat. Technol. and Electrochem., Norwegian Univ. of Sci. and Technol., NO-7491 Trondheim, Norway

来源：

Materials Science Forum | 2000年 / 331卷

关键词：

Annealing - Chromium - Image analysis - Manganese - Nucleation - Optical microscopy - Particles (particulate matter) - Precipitation (chemical) - Reaction kinetics - Solidification - Ternary systems;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The distribution of Mn- and Cr-containing dispersoids during different annealing of three Al-Mg-Si alloys with different content of Mn and Cr has been studied in detail by light microscope. Heating rate and step-annealing to different temperature have been the external parameters. The tendency to heterogeneous distribution of dispersoids was determined by the image analysis Kontron KS 300, and characterised by the parameter Ae defined as the area empty of dispersoids per unit area. The parameter Ae is a measure of regions empty of dispersoids in the material after a specific heat treatment. A tendency towards a nonuniform spatial distribution of dispersoids was related to the nucleation mechanisms of dispersoids and the microsegregation of the alloying elements after non-equilibrium solidification. It was demonstrate that a prerequisite for a homogenous spatial distribution of dispersoids is a heat treatment procedure that produce an abundant density of β′-Mg2Si - needle in a temperature range 250-350°C.

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