Competition behavior of the strengthening effects in as-extruded AZ91 matrix: Influence of pre-existed Mg₁₇Al₁₂ phase

详细信息    查看全文

• 作者：Cui-ju Wang ; Kun-kun Deng ; ^{jamsdk@163.com" class="auth_mail" title="E-mail the corresponding author} ; ^{dengkunkun@tyut.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Kai-bo Nie ; Shuan-jun Shang ; Wei Liang ; ^{liangwky@126.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：AZ91 alloy ; Mg17Al12 phase ; Microstructure ; Mechanical property ; Strengthening mechanism
• 刊名：Materials Science & Engineering A
• 出版年：2016
• 出版时间：22 February 2016
• 年：2016
• 卷：656
• 期：Complete
• 页码：102-110
• 全文大小：3853 K

文摘

The AZ91 alloy containing (“AC”) and without (“AS”) Mg₁₇Al₁₂ phase were both subject to hot extrusion at 693 K with the extrusion ratio of 16:1. Results showed that the pre-existed Mg₁₇Al₁₂ phase in “AC” alloy led to finer grain size and lower intensity of basal plane texture as compared with “AS” alloy. Almost the same YS between “AC” and “AS” alloy indicated that the grain boundary and precipitation strengthening of “AC” alloy was balanced by the texture strengthening and solid solution strengthening of “AS” alloy. Nevertheless, the elongated Mg₁₇Al₁₂ phase along extrusion direction in “AC” alloy reduced its ultimate tensile strength as compared with “AS” alloy. Existence of SiCp led to a dispersive and uniform distribution of Mg₁₇Al₁₂ phase, which gave a full play on grain boundary and precipitation strengthening in “AC” composite. Unlike “AC” alloy, just the uniform and dispersive Mg₁₇Al₁₂ phase in “AC” composite contributed to the higher YS and UTS as compared with “AS” composite.