Ex situ measurement of strain associated with hot tearing in AZ91D and AE42 magnesium alloys using neutron diffraction

• Published in: Canadian journal of physics Vol. 88; no. 10; pp. 715 - 721
• Main Authors: Bichler, L, Ravindran, C, Sediako, D
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 01.10.2010; Canadian Science Publishing NRC Research Press
• Subjects: Alloys; Diffraction; Hearing; Magnesium; Magnesium alloys; Magnesium base alloys; Measurement; Mechanical properties; Microstructure; Neutron diffraction; Neutrons; Physics; Solidification; Strain; Strains and stresses; Stress relaxation (Materials); Stress relieving (Materials); Stresses; Tear behavior; Tearing; Canada
• ISSN: 0008-4204; 1208-6045
• DOI: 10.1139/P09-106

Prevention of hot tearing during casting or welding of commercial alloys remains a challenge for numerous industrial applications. The tendency of an alloy to tear is related to the alloy's microstructure, solidification rate, and the stress/strain conditions it experiences during solidification. Due to technological challenges in performing accurate and reliable measurements, there remains a paucity of quantitative experimental data on the stress/strain conditions associated with the onset of hot hearing. This paper reports on a novel approach to quantify strain at the onset of hot tearing in two magnesium alloys. Neutron diffraction strain mapping was carried out and revealed that in the case of the AZ91D alloy, tensile strain of ~0.05% was associated with initiation of material's plastic damage and hot tearing, while for the AE42 alloy the critical strain was ~0.09%.