镓基液态金属动态流变行为探究  

Dynamic Rheological Behavior of Gallium-Based Liquid Metal

作　　者：谭力笳 杨昭[1] 李斌 程德旭 陈泫宇 严丰 Tan Lijia;Yang Zhao;Li Bin;Cheng Dexu;Chen Xuanyu;Yan Feng(School of Materials Science and Engineering,Central South University,Changsha 401183,China;Jiaxing NBG Electric Co.,Ltd.,Jiaxing 314000,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]嘉兴恩碧技电气有限公司,浙江嘉兴314000

出　　处：《稀有金属》2024年第9期1255-1262,共8页Chinese Journal of Rare Metals

基　　金：国家重点研发计划项目(2022YFE0109600);恩碧技电气有限公司合作项目(H2021100803)资助。

摘　　要：通过研究共晶镓铟锡合金Ga_(66.7)In_(20)Sn_(13.3)(质量分数)的动力粘度,探究了被氧化和未氧化镓基液态金属的流变行为。根据镓基液态金属高表面张力、高密度和低粘度的特点,采用旋转外筒和高密度钼制转子,测量了镓基液态金属在0~120 s^(-1)条件下的动力粘度。结果表明该镓基液态金属表面氧化时流变特性近似呈现出非牛顿假塑性流体特征,流变关系为τ=27.37γ^(0.69)(τ为剪切应力﹐γ为剪切速率),在高剪切速率下粘度稳定在7.27 mPa·s左右;未氧化时镓基液态金属呈现牛顿流体特征,流变关系为τ=4.51γ+4.08,粘度为4.51 mPa·s左右。氧化后镓基液态金属出现的剪切稀现象主要是由呈现弹性的氧化镓薄膜造成的。In recent years,gallium-based liquid alloys had been widely used as coolants in nuclear reactor cooling systems and in concentrating solar energy,as well as lubricants in bearing systems,due to their good fluidity and high thermal conductivity,which had greatly improved the efficiency and performance of these devices.Therefore,it was of great importance to understand the rheological characteristics of liquid gallium-based alloys.Because the rotation method could measure the viscosity at different shear rate,many researchers measured the rheological properties of gallium-based liquid metals by the rotation method and obtained many valuable results.However,due to the high surface tension,high density and low viscosity of gallium-based liquid metal,it was difficult to obtain a relatively stable viscosity value by the rotation method.Therefore this work designed a viscometer with a rotating outer cylinder and Mo central rotator to measure the viscosity of gallium-based liquid metal.The rheological properties of oxidized and unoxidized Ga_(66.7)In_(20)Sn_(13.3)(mass fraction)liquid metals in a wide range of shear rates(0~120 s^(−1))were measured.Ga_(66.7)In_(20)Sn_(13.3) liquid metal was obtained by heating gallium,indium and tin(all 99.999%purity)in argon atmosphere(O^(2)<0.25×10^(−6))to 200℃for 4 h.The melting points of gallium,indium and tin were 30,156.6 and 231.9℃,respectively.The ternary eutectic Ga_(66.7)In_(20)Sn_(13.3) alloy had a melting point of 10.6℃.The coaxial cylinder rotary viscometer(NDJ-5S,Lichen,Shanghai)was used,and the quartz outer cylinder(30 mm in the inner diameter)was driven by the motor and rotates at a speed of(0~306 r·min^(−1)).A pure molybdenum inner rotator with a diameter of 20 mm and a height of 50 mm was used to overcome the buoyancy of liquid metal and enhance the stability of the rotor.The measurement was carried out based on the Couette principle.According to the different rheological laws of Newtonian fluid and non-Newtonian fluid,an approximate shear rate conversion

关 键 词：镓合金 液态金属 粘度 流变特性 旋转法 

分 类 号：TG146.431[一般工业技术—材料科学与工程]