Analyzing Si Precipitation on Age Hardening of an Al-Si-Mg Cast Alloy

Gui Qing Wang; Yan Liu; Guo Cheng Ren; Zhong Kui Zhao

doi:10.4028/www.scientific.net/AMR.146-147.1685

Paper Titles

Comparing Age Hardening Behaviors of Al-3Cu and Al-8Si-3Cu Alloys
p.1667

Microstructure and Mechanical Properties of Ti-6Al-Mo-Fe Alloy Prepared by Powder Metallurgy
p.1671

Preparation and Modification of Nano- TiO₂ Pigment for Coating
p.1675

Comparative Study on Data Editing Techniques for Fatigue Time Series Signals
p.1681

Analyzing Si Precipitation on Age Hardening of an Al-Si-Mg Cast Alloy
p.1685

Influences of Slag and Fly Ash on the Microstructure Property and Compressive Strength of Concrete
p.1690

Application of Artificial Neural Network Based on GA-BP Algorithm to Predicting Mechanical Properties of TC4
p.1698

Microstructure and Creep Property of As-Cast Mg-6Al-xNd (x=2,4,6) Alloys
p.1702

Effective Service Life Assessment of Aluminum Alloy Alclad Corrosion Protection under Equivalent Accelerated Condition
p.1708

HomeAdvanced Materials ResearchAdvanced Materials Research Vols. 146-147Analyzing Si Precipitation on Age Hardening of an...

Analyzing Si Precipitation on Age Hardening of an Al-Si-Mg Cast Alloy

Abstract:

The correlation of age hardening behavior and Si precipitation in α(Al) of Al-8wt%Si-0.35wt%Mg alloy has been investigated by micro hardness measurement, electron probe microanalysis (EPMA) and transmission electron microscopy (TEM) analysis. The EPMA results show that Si concentration in the center of α (Al) dendrites is higher than that in the edge and the main concentration is about 1.5wt% for Al-8wt%Si-0.35wt%Mg alloy in as cast condition. After solution treatment at 530 °C for 8 h followed by water quenching (T4 treatment), hardness value decreases 9 HV, which is accompanied by the decrease of Si concentration in α (Al). Aging the as-cast sample and T4 treatment sample at 150 °C for 20 h, the main concentration of Mg and Si in α (Al) changes little. Hardness value after as-cast aging is only 3 HV lower than that after T6 treatment. Nanometer Si particles and β″ and/or β′ phases are found in aged samples. The higher hardness value for as-cast aging samples should contribute to the nanometer Si particles in α (Al).