The study on microstructural and mechanical properties of weld heat affected zone of 7075-T651 aluminum alloy

Journal Article · Mon Dec 22 04:00:00 EST 1997 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(97)00472-7· OSTI ID:605781

Hwang, R Y; Chou, C P ^[1]

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1. National Chiao Tung Univ., Hsinchu (Taiwan, Province of China). Dept. of Mechanical Engineering

Aluminum alloys play an important role in aerospace industry due to their high strength and low density. The general accepted precipitation behavior of 7075 alloy was represented as: supersaturated solid solution {alpha}{sub ss} {yields} Gp zones {yields} {eta}{prime}(MgZn{sub 2}) {yields} {eta}(MgZn{sub 2}). The Addition of Cu in Al-Zn-Mg alloy would promote the transformation of GP zones into {eta}{prime}(MgZn{sub 2}) phase and stabilize the {eta}(MgZn{sub 2}) phase. The T6 temper has the maximum strength but lower ductility. The T73 temper may lose some strength, but can gain higher corrosion resistance and lower susceptibility to stress corrosion cracking as compared to the T6 temper. The welding fabrication can produce thermal cycling on the weldment. In the heat affected zone (HAZ) beside the fusion zone, different temperatures can be obtained. This would cause change of microstructure in the HAZ of aluminum alloy weldment. Many workers studied the behavior of weld HAZ by cutting the HAZ into many small pieces or using short time isothermal heat treatment to simulate the HAZ. This may lose some information, especially near the fusion zone, because high temperature gradient occurred in this region. In this study, the Gleeble system was used to simulate the weld HAZ. It can accurately simulate every point of weld HAZ by heating and cooling the specimen to the thermal history of weld HAZ as the same as measured. The microstructural and mechanical properties of weld HAZ of 7075-T651 alloy were investigated.

• OSTI ID: 605781
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 2 Vol. 38; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM BASE ALLOYS
HEAT AFFECTED ZONE
MECHANICAL PROPERTIES
MICROSTRUCTURE
PHASE TRANSFORMATIONS