摘要钼是一种高性能材料,具有优异的高温力学性能、高硬度、高强度、高弹性模 量,导电和导热系数很高,而热膨胀系数较低,是很有应用前景的难熔金属材料之 一。但钼金属具有体心立方金属所固有的低温脆性和韧脆过渡的特点,并且高温抗 氧化能力和焊接性能极差,这限制了其作为结构材料的广泛使用。经研究发现在钼 中加入铼元素可以很好的改变钼的性能,形成钼铼合金。钼铼合金是具有良好的热 稳定性和耐化学腐蚀性的结构材料。 80640
本论文的核心目的是研究钼铼合金的钎焊,采用 Fe 基非晶态钎料来焊接钼铼 合金,详细的介绍了钼铼合金的焊接方法,指出了钼铼合金的研究方法,也就是高 温钎焊。探究钼铼合金的钎焊机理,分别使用金相显微镜、扫描电镜、XRD 等进行 焊接式样组织的观察,并且分析了元素分布。
综合试验结果、金相分析和力学实验可知,钼铼合金钎焊过程中母材和钎料元 素相互扩散,得到性能良好的焊接接头,接头晶粒分布均匀,晶粒细化,有较高的 强度,但在焊缝中心处有少量化合物影响接头质量。
毕业论文关键字:钼铼合金 显微组织 元素分布 接头性能
Abstract Molybdenum is a kind of high performance material, has excellent high temperature mechanical properties, high hardness, high strength, high modulus of elasticity, conducting and the coefficient of thermal conductivity is very high, and low thermal expansion coefficient, is of great application prospect is one of the refractory metal materials。But molybdenum metal with body centered cubic metal inherent brittleness at low temperature, and the characteristics of the ductile brittle transition, and the high temperature oxidation resistance and welding performance is poor, which limits its widespread use as a structural material。Studies found in molybdenum rhenium elements can be very good changes the properties of molybdenum formed molybdenum rhenium alloy。Molybdenum rhenium alloy is has good thermal stability and resistance to chemical corrosion resistance of structural materials。
The core purpose of this paper is the study of molybdenum rhenium alloy brazing, using Fe base amorphous welding molybdenum rhenium alloy solder, detailed introduces the molybdenum rhenium alloy welding method, points out the research method of molybdenum rhenium alloy, namely high temperature brazing。Explore molybdenum rhenium alloy brazing mechanism, respectively using metallographic microscope, sem, XRD, etc for welding style organization of observation, and element distribution were analyzed。
Comprehensive test results, metallographic analysis and mechanics experiment, the molybdenum rhenium alloy brazing solder material and elements in the process of mutual diffusion, get good performance of welded joint, joint uniform grain size distribution, grain refinement, have higher strength, but had a small amount of compounds in the center of the weld joint quality。
Keywords: Mo-Re alloy ; microscopic structure ; Element distribution ; joint performance
目录
第一章绪论 。 1
1。1 课题背景 1
1。2 钼铼复合材料 1
1。2。1 基本特征 1
1。2。2 生产工艺 2
1。3 钼及钼合金材料的连接方法 3
1。3。2 钼及钼合金焊接首要难题 5
1。4 钎焊的相关理论 7
1。5 课题研究 7