Surface treatment to reduce and redistribute residual-stresses in A7N01 weld by micro-arc oxidation

详细信息    查看全文

• 作者：Zongtao Zhu ; Yuanxing Li ; Xuefei Wang ; Hui Chen ; ^{xnrpt@swjtu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; ^{xnrpt@163.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Aluminum alloy ; Welded joints ; Micro-arc oxidation ; Residual stress ; Fatigue
• 刊名：Journal of Materials Processing Technology
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：231
• 期：Complete
• 页码：248-253
• 全文大小：2047 K

文摘

Micro-arc oxidation (MAO) process is applied to the surface treatment of A7N01 alloy welded joint to improve the residual-stress distribution and its properties. Oxide ceramic coating with a thickness of 13 μm is prepared on the surface of the welded joints. The resulting residual stress of welded joint decreases significantly. The transverse residual stress σ_y on the region of weld metal, with a peak tensile stress of 220 MPa, drops to a compressive stress of 30 MPa. The treated A7N01 joint has better anti-corrosion property, due to the protection of ceramic coating and the decreasing trends of stress corrosion with lower tensile stress. Both impact toughness and tensile strength of the treated joints are improved. The fatigue test shows that the fatigue performance is improved due to the resulting compressive stress during MAO processing. The SEM observation results show that the fatigue crack originates at the hard phase in sub-surface, not the micro-porous of the coating.