(1. 河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽 471003；
2. 河南省有色金屬材料科學(xué)與加工技術(shù)重點(diǎn)實(shí)驗(yàn)室，洛陽 471003；
3. 上海理工大學(xué) 機(jī)械工程學(xué)院，上海 200093)
摘 要: 研究在AZ31B變形鎂合金中添加稀土Nd對AZ31B合金鑄態(tài)和熱軋退火態(tài)性能及組織的影響。結(jié)果表明：在AZ31B變形鎂合金中添加Nd后，合金的鑄態(tài)和熱軋退火態(tài)的室溫抗拉強(qiáng)度和伸長率均降低；加入的Nd與Al形成Al2Nd相，Nd還可以與Al和Mn形成Al-Nd-Mn化合物，剩余的Al還可以和Mg形成Mg17Al12相。含Al和Mn的金屬間化合物削弱元素Al、Mn對鎂合金的晶粒細(xì)化作用導(dǎo)致晶粒粗大，進(jìn)而降低鑄態(tài)AZ31B合金性能；熱穩(wěn)定性好的粗大第二相的出現(xiàn)也是導(dǎo)致合金鑄態(tài)性能降低的原因，增大變形量使第二相得到充分破碎，會(huì)使板材力學(xué)性能得到改善。
關(guān)鍵字: 變形鎂合金；AZ31鎂合金；稀土；第二相
of AZ31B wrought magnesium alloy
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China;
2. Henan Key Laboratory of Advanced Non-ferrous Metals, Luoyang 471003, China;
3. College of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China）
Abstract:The effects of rare earth Nd on the microstructures and mechanical properties of as-cast and hot-rolled AZ31B wrought magnesium alloy were investigated. The results show that the mechanical properties of both as-cast and hot-rolled AZ31B alloys at room temperature decrease due to rare earth Nd addition. When rare earth Nd is added into AZ31B alloy, the Nd reacts with Al element to form Al2Nd phase, the Nd may also reacts with Mn and Al to form Al-Nd-Mn intermetallics compounds, the residual Al reacts with Mg to form Mg17Al12 phase. The intermetallics compound containing Al and Mn weakens the grain refinement effect of Al and Mn on AZ31B alloy and results in the declining of mechanical properties of as-cast AZ31B alloy. The thermostable and bulky second phase is another main reason for the declining the mechanical properties of as-cast AZ31B alloy. The bulky second phase is the main reason to result in the declining of mechanical properties of hot-rolled sheet of AZ31B alloy. The mechanical properties of hot-rolled sheet of AZ31B-0.8Nd alloy can be improved through increasing the strain of hot rolling because the second phase are adequately refined by large deformation.
Key words: wrought magnesium alloy; AZ31 Mg alloy; rare earth; second phase
