(1. 太原理工大學(xué) 材料科學(xué)與工程學(xué)院，太原 030024；
2. 太原理工大學(xué) 新材料界面科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，太原 030024)
摘 要: 鎂合金因放電穩(wěn)定、成本低、標(biāo)準(zhǔn)電位較負(fù)非常適合作為電池陽極材料，而目前常用的正擠壓態(tài)陽極鎂合金往往會(huì)由于晶粒尺寸差異大、第二相分布不均勻而導(dǎo)致較差的放電性能。為提高擠壓態(tài)合金的放電性能，采用等通道擠壓(ECAP)技術(shù)對(duì)擠壓態(tài)Mg-9Al-1.5Bi-0.5In合金進(jìn)行變形處理，并對(duì)其進(jìn)行組織觀察及電化學(xué)測(cè)試。研究結(jié)果表明：ECAP后合金發(fā)生了完全動(dòng)態(tài)再結(jié)晶，晶粒細(xì)化，第二相分布均勻；隨著ECAP道次的增加，晶粒尺寸、第二相尺寸均先減小后增大，而第二相的體積分?jǐn)?shù)先增大后減小，在2道次時(shí)達(dá)到最值；此外，2道次合金具有較好的電化學(xué)活性，腐蝕電流密度和腐蝕電位分別為126.63 μA/cm2、-1.48713 V，在較小電流密度下，2道次合金具有最大的利用率(53.74%)、功率密度(43.181 mW/cm2)和比容量(1412.574 mA·h/g)。因此，在小電流狀態(tài)下，ECAP 2道次的Mg-9Al-1.5Bi-0.5In合金具有廣闊的應(yīng)用前景。
關(guān)鍵字: 鎂合金；正擠壓；ECAP；顯微組織；電化學(xué)性能
（1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024;
2. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China）
Abstract:Magnesium alloy is suitable for anode material of battery due to stable discharge, low cost and negative standard potential. However, the commonly used positive extruded anode magnesium alloy often has poor discharge performance due to large grain size difference and uneven distribution of the second phase. In order to improve the discharge performance of extruded alloy, equal channel corner extrusion (ECAP) technique was used to deform the extruded Mg-9Al-1.5Bi-0.5In alloy, and the microstructure observation and electrochemical test were carried out. The results show that complete dynamic recrystallization occurs after ECAP, the grain size is refined and the second phase is evenly distributed. With the increase of extrusion pass, the grain size and the second phase size both decrease first and then increase, while the volume fraction of the second phase increases first and then decreases, reaching the extreme value when the extrusion pass is 2. The alloy with extrusion pass of 2 has better electrochemical properties, and the corrosion current density and corrosion potential are 126.63 μA/cm2 and -1.48713 V, respectively. The alloy with extrusion pass of 2 has the highest utilization rate (53.74%), power density (43.181 mW/cm2) and specific capacity (1412.574 mA？h/g). Therefore, Mg-9Al-1.5Bi-0.5In alloy with extrusion pass of 2 is widely used in low current state.
Key words: magnesium alloy; forward extrusion; ECAP; microstructure; electrochemical property
