电流密度对V-4Cr-4Ti合金基体上电沉积W涂层显微结构的影响  

EFFECTS OF CURRENT DENSITY ON MICROSTRUCTURE OF W COATING ON V-4Cr-4Ti ALLOY BY ELECTRODEPOSITION

作　　者：李绪亮[1] 张迎春[1] 江凡[1] 王莉莉[1] 刘艳红[1] 孙宁波[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《金属学报》2013年第6期745-750,共6页Acta Metallurgica Sinica

基　　金：国际热核聚变实验堆(ITER)计划专项项目2010GB109000;国家自然科学基金项目50972008资助~~

摘　　要：利用Na_2WO_4-WO_3熔盐体系在V-4Cr-4Ti合金基体上电沉积制备了金属W涂层,在电流密度为10-160 mA/cm^2范围内研究了电流密度对金属W涂层的显微结构和力学性能的影响.研究结果表明,增大电流密度促进了W晶核的生长以及晶粒尺寸的增大.W原子更容易在V-4Cr-4Ti合金基体上形核,而在初始W晶核上继续沉积主要是W晶核长大的过程,电流密度较大(100 mA/cm^2)时,W涂层的金相组织呈柱状和条状结构,电流密度较小时,W涂层组织呈牙柱状.W涂层的硬度随着电流密度的增加而下降,W涂层与V-4Cr-4Ti合金基体的结合强度超过59.36 MPa.电流密度为10 mA/cm^2时,虽然涂层厚度仅有10μm,但W涂层晶粒尺寸小于5μm,涂层硬度、电流效率以及涂层和基体的结合力达到最大值,分别为628.42 HV,99.71%和96 N.The W coatings prepared on structure materials （V-4Cr-4Ti） as plasma facing mate- rials, not only can release impinging thermal power but also can resist erosion under plasma particles bombardment in international thermonuclear experimental reactor. The electro deposition of W in Na2WO4-WO3 melt as a promising technique was studied in this work. The effects of current density on mierostructure and mechanical properties of W coating were investigated, and the results show that, with the increasing of the current density, the trend of crystal growth is promoted and the grain size of W coatings increased. The nucleation easily occurs on V-4Cr-4Ti alloy substrate for W atom, and af- ter that, the growth of crystal nuclei is the most important factor for the formation of coatings. When the current density increases to 100 mA/cm2, the metallographic structure of W coatings presents columnar or stripy structure, and tooth-like grains were presented in microstructure as current density is lower. The Vickers micro-hardness of W coatings is decreased as increasing current density, and the adhesive strength of the coatings is greater than 59.36 MPa by the tensile test. Although the thickness of tungsten coatings is 10 μm as current density is 10 mA/cm2, grain size is less than 5 μm, Vickers hardness, current efficiency and the coatings adhesion are all maximum, and the values are 628.42 HV, 99.71% and 96 N respectively.

关 键 词：W涂层 Na2WO4-WO3 电沉积 电流密度 

分 类 号：TQ153.19[化学工程—电化学工业] TF111.52[冶金工程—冶金物理化学]