电磁悬浮下不同凝固方式对Ti-48Al-2Cr合金显微组织的影响  

Effect of different solidification ways on microstructure of Ti-48Al-2Cr alloy under electromagnetic levitation

作　　者：潘哲儒 张桂芳[1,2] 严鹏 刘宇[1] 张培培 冯振华 田楠 PAN Zhe-ru;ZHANG Gui-fang;YAN Peng;LIU Yu;ZHANG Pei-pei;FENG Zhen-hua;TIAN Nan(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;Key Laboratory of Complex Iron Resources for Clean Metallurgy,Education Department of Yunnan Provincial,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093 [2]云南省高校复杂铁资源清洁冶金重点实验室,云南昆明650093

出　　处：《材料热处理学报》2023年第1期58-65,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(52074140)。

摘　　要：钛铝基合金凝固组织是控制其性能的关键因素,电磁悬浮技术作为一种非接触式熔炼技术,能够显著改善合金凝固组织的形貌,从而改善其性能。采用电磁悬浮技术和不同的凝固条件对Ti-48Al-2Cr(at%)合金进行了处理,并研究了其显微组织形态结构特征。结果表明:电磁悬浮后合金的凝固组织明显区别于原始合金的凝固组织;有容器凝固的显微组织呈现放射状细密结构,出现了粗大的枝状晶体形貌,无容器凝固的显微组织呈现出典型的片层结构,显著改善了凝固组织;电磁悬浮下无容器凝固方式的Ti-48Al-2Cr合金显微组织是不同方向分布的α_(2)+γ片层状组织,片层组织晶粒尺寸随着He气流量上升而减小,晶粒显著细化,当电磁悬浮气氛He气流量从3.0 L/min增加至5.0 L/min时,合金的晶粒尺寸从282.5μm减小至206.6μm,晶粒尺寸细化了26.9%。The solidification structure of titanium-aluminum-based alloy is the key factor to control its performance.As a non-contact melting technology,electromagnetic levitation can significantly improve the morphology of the solidification structure of the alloys,thereby improving their performance.The Ti-48Al-2Cr(at%)alloy was treated by electromagnetic levitation technology and under different solidification conditions,and its microstructure,morphology and structure characteristics were studied.The results show that the solidification microstructure of the alloy after electromagnetic levitation is obviously different from that of the original alloy.The microstructure of the sample solidified with container presents radial and fine structure,and coarse dendritic crystal morphology appears,while the microstructure of the sample solidified without container presents typical lamellar structure,which significantly improves the solidification microstructure.The microstructure of the Ti-48Al-2Cr alloy solidified without container under electromagnetic levitation is α_(2)+γ lamellar structure distributed in different directions,the grain size of lamellar structure decreases with the increase of He gas flow rate,and the grain is significantly refined.When the He gas flow rate of electromagnetic suspension atmosphere increases from 3.0 L/min to 5.0 L/min,the grain size of the alloy decreases from 282.5μm to 206.6μm,and the grain size is refined by 26.9%.

关 键 词：Ti-48Al-2Cr合金 电磁悬浮 凝固条件 微观结构表征 

分 类 号：TG146.2[一般工业技术—材料科学与工程]