摘要：现代热切割工艺方法主要分为三种:火焰加热切割、等离子切割、激光切割。火焰切割适用于厚板材，并且对切割质量和精度要求不高的材料，但是火焰切割设备便宜，操作简便，适用范围广。激光切割只能用于比较薄的板材，而且设备一次性投资很大，生产成本很大，但是激光切割精度很高可以达到0.05mm，有些甚至可以达到0.02mm左右，所以对于切割质量要求很高的材料，激光切割是很好的方法。而等离子切割质量介于火焰切割和激光切割之间，切割精度比火焰 切割高很多，稍低于激光切割，并且等离子切割设备较为便宜，可以带来更好的社会经济效益。等离子切割是现在用途最广泛的切割方法。但是根据现在的了解等离子切割机的平均使用寿命都不是很长，使用效率都不是很高，给现代生产带来了不小的困难。等离子切割机的使用寿命主要和等离子电极的发射体的寿命有关。之前发射体大都是金属铪和铜通过焊接起来的，使用效率都不是很好。本次实验采用纯铜和925银的扩散焊作为发射体，用4组试样，分别在760度下保温：0.5h，1h，2h，4h。然后通过观察焊缝处的晶像组织，测试焊缝处的剪切强度，再用扫描电子显微镜和能谱仪测试焊缝处的成分进行分析，探索扩散焊能否实现925银和铜的连接，最后找到一条最好的加工工艺方法。根据实验结果表明，扩散焊可以实现925银和铜的连接，并且焊接界面的强度随着保温时间的提高而提高

关键词：扩散焊；等离子切割；力学性能；组织成分分析

Abstract：The modern thermal cutting process is mainly pided into three types: flame cutting, plasma cutting, laser cutting, flame cutting is suitable for thick plate, and the requirements of quality and accuracy of cutting materials is not high, but the flame cutting equipment is inexpensive, simple operation, wide application range. Laser cutting can only be used for relatively thin sheet, and the one-time investment is large, the production cost is very big, but very high precision laser cutting can reach 0.05mm, and some can even reach about 0.02mm, so for the cutting of high quality requirements of materials, laser cutting is a good method. But the quality of plasma cutting between flame and shock Light cutting, cutting accuracy is much higher than the flame cutting, slightly lower than the laser cutting and plasma cutting equipment is cheaper, can bring better social and economic benefits. The plasma cutting is now the most widely used methods of cutting. But according to the current understanding of the average life of plasma cutting machine is not very long, the use efficiency is not very high, difficult to bring modern production. The emission of plasma cutting machine service life and the life of the main plasma electrode. Before the emitter is mostly metal hafnium and copper by welding, the use efficiency is not very good. This experiment adopts pure copper and silver 925 The diffusion welding as the emitter, with 4 sets of samples, respectively. At 760 degrees: 0.5h, 1H, 2h, 4h. and then by observing the weld crystal like tissue, shear strength test of weld, and scanning electron microscopy and EDS test weld components were analyzed, to explore the diffusion welding can connect 925 silver and copper, and finally find a best processing method.According to the experimental results, the bonding between 925 silver and copper can be achieved by diffusion welding, and the strength of the welding interface increases with the increase of holding time

Keywords: Diffusion welding；Plasma cutting；mechanical property；Tissue composition analysis

目录

第1章绪论 1

1.1扩散焊 1

1.1.1扩散焊的原理 1

1.1.2扩散焊的影响因素 2

1.1.3扩散焊的优缺点 3

1.1.4扩散焊的应用 4

1.2空气等离子切割 5

1.2.1空气等离子切割原理 5