Influence of heat treatment on fatigue behaviour of high-strength Mg–10Gd–3Y alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 527; no. 21; pp. 6053 - 6063
• Main Authors: Dong, J., Liu, W.C., Song, X., Zhang, P., Ding, W.J., Korsunsky, A.M.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 20-08-2010; Elsevier
• Subjects: Aging (artificial); Applied sciences; Close packed lattices; Exact sciences and technology; Fatigue; Fatigue (materials); Fatigue strength; Fractures; Heat treatment; High cycle fatigue; Magnesium alloy; Magnesium base alloys; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Mg–10Gd–3Y; Microstructure; Solution heat treatment; Heat treatment; High cycle fatigue; Mg–10Gd–3Y; Magnesium alloy; Fatigue life; Overageing; Ageing; Fatigue crack; Crack propagation; Solution heat treatment; Magnesium base alloys; Fatigue strength; Mg―10Gd―Y; Microstructure; Fractography; Crack initiation
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2010.06.030

The current work investigated the influence of heat treatment (T4, T5 and T6) on high cycle fatigue (HCF) behaviour of the as-extruded Mg–10Gd–3Y (GW103, wt.%) alloy. The five heat treatment conditions applied to the as-extruded GW103 alloy were under-aging (T5, 225
°C
×
4
h), peak-aging (T5, 225
°C
×
10
h), over-aging (T5, 225
°C
×
250
h), solution treatment (T4, 500
°C
×
4
h), solution treatment plus artificial aging (T6, 500
°C
×
4
h
+
225
°C
×
10
h), respectively. The results showed that T5 heat treatment can improve the fatigue behaviour of the GW103 alloy, while T4 and T6 heat treatments are detrimental to the fatigue behaviour of the GW103 alloy. The 10
7 cycles fatigue strength of the GW103 alloy made by peak-aging was improved by approximately 10%, compared with the as-extruded. While, the fatigue strength of the under-aged and over-aged GW103 alloys have no obvious difference, although fatigue life of the under-aged GW103 alloy is slightly higher than that of the over-aged GW103 alloy at high stress amplitude. The extruded-T4 and extruded-T6 GW103 alloys exhibit similar fatigue strengths of 110
MPa. The influence mechanism of heat treatment on HCP behaviour of the as-extruded GW103 alloy was discussed.