Effect of Liquid Hot Isostatic Pressing on Structure and Mechanical Properties of an Aluminum Alloy

Abstract:

The effect of liquid hot isostatic pressing (LHIP) on microstructure and mechanical properties of a high-strength cast Al-6Zn-2Mg-0.5Fe-0.7Ni alloy was examined. LHIP eliminates shrinkage porosity that highly improves strength and fatigue limit. Yield stress (YS) and ultimate tensile strength (UTS) in T6 condition increased from 135 to 470 MPa and from 410 to 510 MPa, respectively. Endurance limit on the base of 10⁷ cycles increased from 95 to 140 MPa. However, a small number of gas pores with an average size less than 2 μm retains. LHIP suppresses the crack initiation on coarse cavities. However, brittle intergranular fracture occurs in the hipped alloy through the breaking of eutectic phase Al₉FeNi. As a result, elongation-to-failure was of 1.2% and the fatigue strength is equal to one of AA356.02 alloy subjected to LHIP.

• Periodical: Materials Science Forum (Volumes 794-796)
• Pages: 845-850
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.794-796.845
• Online since: June 2014
• Authors: Damir Tagirov*, Vladislav Kulitskiy, Nikolay Belov, Rustam Kaibyshev
• Keywords: Aluminium Alloy, Casting, Fatigue, LHIP, Mechanical Property

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DOI: 10.1017/s000192400008670x

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