(1. 重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400044；
2. 重慶大學(xué) 國(guó)家鎂合金材料工程技術(shù)研究中心，重慶 400044)
摘 要: 研究超聲處理對(duì)Mg-6Zn-0.5Y-2Sn合金顯微組織及力學(xué)性能的影響。結(jié)果表明，超聲處理對(duì) Mg-6Zn- 0.5Y-2Sn合金顯微組織及力學(xué)性能有顯著影響。Mg-6Zn-0.5Y-2Sn合金是由α-Mg相、MgZn2相、MgSnY相、Mg2Sn相和少量I相組成。經(jīng)超聲處理后，I相基本消失，并且隨著超聲功率的提高，粗大的枝晶結(jié)構(gòu)逐漸變成圓整的等軸晶，位于晶界附近粗大、半連續(xù)、不均勻分布的第二相逐漸變得細(xì)小、不連續(xù)、均勻且彌散分布。當(dāng)超聲功率達(dá)到700 W時(shí)，Mg-6Zn-0.5Y-2Sn合金的綜合力學(xué)性能達(dá)到最佳。與未超聲處理的鎂合金相比，其屈服強(qiáng)度、極限抗拉強(qiáng)度和伸長(zhǎng)率分別提高了28%、30% 和67%。
關(guān)鍵字: Mg-6Zn-0.5Y-2Sn合金；超聲處理；顯微組織:力學(xué)性能
（1. School of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044, China）
Abstract:The effects of the ultrasonic treatment on the microstructure and mechanical properties of Mg-6Zn-0.5Y-2Sn alloy were investigated. The results show that the ultrasonic treatment has significant effect on the microstructure and mechanical properties of Mg-6Zn-0.5Y-2Sn alloy. The phases in Mg-6Zn-0.5Y-2Sn alloy are α-Mg, MgZn2, MgSnY, Mg2Sn, and a small amount of I-phase. With the application of ultrasonic treatment, I-phase nearly disappears, and with increasing the ultrasonic treatment power, the coarse dendrites gradually change into roundish equiaxed grains. The second phases at the α-Mg boundaries transform from coarse, semicontinuous and non-uniform to fine, discontinuous, uniform and dispersive. When the ultrasonic treatment power is 700 W, the best comprehensive mechanical properties of Mg-6Zn-0.5Y-2Sn alloy are obtained. Compared with the untreated alloy, the 0.2% tensile yield strength, ultimate tensile strength and elongation are improved by 28%, 30% and 67%, respectively.
Key words: Mg-6Zn-0.5Y-2Sn alloy; ultrasonic treatment; microstructure; mechanical properties
