Relationship between microstructure and tensile fracture of 6082-T6 aluminum alloy

doi:10.13251/j.issn.0254-6051.2021.05.007

Abstract

Abstract: Mechanical properties of the aged 6082-T6 aluminum alloy were studied by means of static tensile method. The microstructure of the alloy was observed by means of optical microscopy (OM) and transmission microscopy (TEM). The tensile fracture morphologies were studied by means of scanning electron microscopy (SEM), and precipitated phase distribution of the alloy was analyzed by means of electronic probe (EPMA). The relationship between microstructure and tensile fracture was comprehensively analyzed. The results show that the aged 6082-T6 aluminum alloy has high yield ratio, of which the tensile strength is 345 MPa and yield strength is 326 MPa. The spherical pit-like black Mg₂Si precipitated phase is distributed in the aluminum alloy, meanwhile white iron-rich inclusion phase α-AlMnFeSi is also present. Tensile fracture of the aged 6082-T6 aluminum alloy has obvious dimple-type fracture characteristics. When the stress concentration caused by dislocation pile-up exceeds the weak interface bonding strength, local fracture of the alloy matrix will occur, and pit-like dimples will be formed from the fracture around the brittle precipitated phase particles, and finally dimple-type fracture will form, containing hard and brittle inclusions.

Key words: 6082-T6 aluminum alloy, aging treatment, microstructure, fracture morphology, fracture mechanism

CLC Number:

TG166.3

Zhu Gaojie, Zou Longjiang, Ren Xiaolei, Li Chunhui, Liu Shutan. Relationship between microstructure and tensile fracture of 6082-T6 aluminum alloy[J]. Heat Treatment of Metals, 2021, 46(5): 47-54.

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