(1. 蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050；
2. 蘭州理工大學(xué) 有色金屬合金及加工教育部重點(diǎn)實(shí)驗(yàn)室，蘭州 730050)
摘 要: 通過半固態(tài)等溫?zé)崽幚恚芯勘販囟群捅貢r(shí)間對Mg-7Zn-0.3V鎂合金把固態(tài)組織演變的影響。結(jié)果表明：保溫溫度和保溫時(shí)間對Mg-7Zn-0.3V非枝晶組織的演變有重要的影響。提高保溫溫度或是延長保溫時(shí)間，可以使Mg-7Zn-0.3V中的非枝晶組織轉(zhuǎn)變?yōu)楦蛹?xì)小且分布均勻的球狀顆粒。當(dāng)保溫溫度過高或是保溫時(shí)間過長時(shí)，半固態(tài)顆粒會出現(xiàn)合并和長大，其主要的演變機(jī)制與Ostwald熟化規(guī)律相符合。Mg-7Zn-0.3V合金的最佳等溫?zé)崽幚砉に囀牵罕販囟?05 ℃，保溫時(shí)間40 min，非枝晶顆粒的平均尺寸為48.5 μm，形狀因子為1.26。
關(guān)鍵字: Mg-7Zn-0.3V鎂合金；半固態(tài)等溫處理；非枝晶組織；演變機(jī)理
（1. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;
2. Key Laboratory of Non-ferrous Metal Alloys and Processing, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:The effects of remelting temperature and holding time on microstructural evolution of Mg-7Zn-0.3V magnesium alloy were investigated by semi-solid isothermal heat treatment. The results indicate that the holding temperature and holding time have significant effects on microstructural evolution of the Mg-7Zn-0.3V alloy during isothermal temperature process. By increasing the holding temperature or prolonging the holding time, the non-endritic structures in Mg-7Zn-0.3V can be transformed into smaller and more uniform spherical particles.When the holding temperature is too high or holding time is too long, the semi-solid particles will combine and grow up, the microstructural evolution mechanism is consistent with the rule of Ostwald ripening mechansim. The best parameters of isothermal heat treatment are 605 ℃ holding temperature and 40 min holding time, obtaining the semi-solid microstructure with the average partial size of 48.5 μm and the roundness of 1.26.
Key words: Mg-7Zn-0.3V magnesium alloy; semi-solid isothermal heat treatment; non-endritic structure; evolution mechanism
