Grain boundary sliding mechanism during high temperature deformation of AZ31 Magnesium alloy

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:669

Article

Roodposhti, Peiman Shahbeigi^1,2  Sarkar, Apu¹  Murty, Korukonda Linga¹  Brody, Harold²  Scattergood, Ronald¹ 

[1] N Carolina State Univ, Raleigh, NC 27606 USA

[2] Univ Connecticut, Storrs, CT USA

关键词: AZ31;    Creep;    Grain boundary sliding;    Cavity formation;   

DOI  :  10.1016/j.msea.2016.05.076

来源: Elsevier

【 摘 要 】

High temperature tensile creep tests were conducted on AZ31 Magnesium alloy at low stress range of 1-13 MPa to clarify the existence of grain boundary sliding (GBS) mechanism during creep deformation. Experimental data within the GBS regime shows the stress exponent is 2 and the activation energy value is close to that for grain boundary diffusion. Analyses of the fracture surface of the sample revealed that the GBS provides many stress concentrated sites for diffusional cavities formation and leads to premature failure. Scanning electron microscopy images show the appearances of both ductile and brittle type fracture mechanism. X-ray diffraction line profile analysis (based on Williamson-Hall technique) shows a reduction in dislocation density due to dynamic recovery (DRV). A correlation between experimental data and Langdon's model for GBS was also demonstrated. (C) 2016 Elsevier B.V. All rights reserved.

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