摘要Si3N4 陶瓷是一种综合性能较好的高温结构陶瓷材料，它具有高温强度高、 热稳定性好、耐磨、耐腐蚀、抗震、热膨胀系数小、原料丰富等优点，研究 Si3N4 陶瓷的连接具有很高的使用价值。本文选用 Cu-Ti 活性钎料钎焊连接经过表面预 金属化处理的 Si3N4 陶瓷，研究了不同 Ti 含量的钎料和不同的钎焊工艺参数以及 不同的预金属化工艺对钎焊接头组织和性能的影响。通过液压万能试验机和超景 深数码显微镜分析了焊缝的力学性能和显微结构。79806

使用的 Cu-Ti 钎料中 Ti 含量在 15%~30%之间时，随着 Ti 含量的升高，钎料 的液相线越低，Ti 含量在 15%~25%之间增加时，钎料的液相线温度降低明显， Ti 含量在 25%~30%之间增加时，钎料的液相线温度降低较少。同时随着 Ti 含量 的增加钎料的三点弯曲强度增加，但是当钎料中 Ti 含量高于 25%是，Ti 含量的 增加会降低钎料的三点弯曲强度。添加 Cu、Ti 过渡层可以提高 Si3N4 的钎焊强 度。但 Cu200w 降低到 150w 钎焊接头的强度没有明显变化。加入 Mo 元素可以 细化焊缝反应层金属，并降低钎料的热膨胀系数，三点弯曲强度得到明显的提高， 同时 Mo 元素起到细化晶粒的作用，减少钎料中 Cu 集聚。

关键词：Si3N4 陶瓷；Cu-Ti 钎料；真空钎焊；润湿性能；显微结构

Abstract Si3N4 ceramic is a kind of high temperature structure  ceramic  material with good comprehensive performance。 It has the advantages of high temperature strength, good thermal stability, wear resistance, corrosion resistance, low thermal expansion coefficient, rich raw materials and so on。 It is very valuable to study the connection of Si3N4 ceramics。 We choose Ti active filler metal  connection through metal surface pre processing of Si3N4 ceramic to study the influence of different content of Ti alloy and different brazing parameters and different pre metallization process on the microstructure and properties of the welded joint。 Through the hydraulic universal testing machine and super depth digital microscope analysis of the mechanical properties and microstructure of weld。

The Ti content in the use of Cu Ti brazing filler metal between 25% to 30%, with the increase of Ti content, the lower the liquidus temperature of solder, Ti content in between 15-25 percent increase, the liquidus temperature of the solder decreased significantly, increasing of Ti content in 15% to 30% between, the liquidus temperature of the solder less reduction。 At the same time, with the increase of Ti content, the three point bending strength increases, but when the content of Ti in the solder is higher than 25%, the increase of Ti content will decrease the  bending strength of the three point of the solder。 Adding Cu and Ti transition  layer can improve the brazing strength of Si3N4。 But the strength of Cu200w reduced to 150W solder joint has no obvious change。 The addition of Mo can refine the weld metal, and reduce the coefficient of thermal expansion, the three point bending strength is obviously improved, and the Mo element plays a role in the refinement of the grain, reducing the Cu concentration in the solder。

Keywords ： Si3N4 ceramic; Cu-Ti solder; vacuum brazing; wetting property; microstructure

目录

第一章：绪论 1

1。1  课题背景及意义 1

1。2 Si3N4 陶瓷 1

1。2。1 Si3N4 简介 1

1。2。2 Si3N4 的活性钎焊 4

1。3  钎焊 4

1。3。1 钎焊的特点 4

1。3。2 钎焊的分类