钎缝间隙对不同镍基合金真空钎焊搭接接头组织和性能的影响  

Effect of Brazing Clearance on Microstructure and Properties of Vacuum Brazing Lap Joint of Ni-Based Alloys

作　　者：于治水[1] 石昆[1] 李瑞峰[1] 

机构地区：[1]上海工程技术大学材料工程学院,上海201620

出　　处：《机械工程材料》2010年第7期5-7,11,共4页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(50875160);上海市教委重点学科建设资助项目(J51402);上海市科委计划项目(071005120)

摘　　要：采用镍基钎料BNi-2对镍基合金GH738和GH4169进行了1 080℃、不同钎缝间隙的真空钎焊,通过光学显微镜、扫描电镜及其附带的能谱仪和显微硬度计等研究了钎缝间隙对镍基合金接头显微组织、成分分布以及显微硬度分布的影响。结果表明:不同钎缝间隙接头的钎缝区均由两边的固溶体、中间的金属间化合物组成;接头显微硬度均呈现中间高两边低的变化趋势;随着钎缝间隙的减小,钎料与母材的扩散反应越充分,从而使得钎缝中金属间化合物的含量越少,固溶体含量增多,接头硬度下降;当钎缝间隙为30μm时,接头组织基本为固溶体。Nickel-based alloys GH738 and GH4169 were joined using Ni-based filler BNi-2 at brazing temperature of 1 080℃ with different brazing clearances. The effect of brazing clearance on the microstructure, composition distribution and micro-hardness distribution of the Ni-based alloy joint was investigated by means of optical microscopy, scanning electron microscopy with energy dispersive X-ray spectrometer and micro-hardness tester. The results show that the brazed joints in brazed seam with different brazing clearances were all composed of solid solution in both sides and intermetallics in the center. The micro-hardness of the brazed joints in the middle was higher than that in the sides. With the decrease of brazing clearance, the diffusion reactions of the filler and the base metal were more full, that could decrease the content of intermetallics in the brazing clearance. The more the content of solid solution, the lower the hardness of joint. When the brazing clearance was 30 ℃m, the microstructure of the jiont was solid solution.

关 键 词：真空钎焊 镍基合金 钎缝间隙 

分 类 号：TG454[金属学及工艺—焊接]