粉末等离子喷焊机的关键技术研究

发布时间：2017-12-28 20:14

本文关键词：粉末等离子喷焊机的关键技术研究　出处：《武汉轻工大学》2015年硕士论文　论文类型：学位论文

【摘要】：粉末等离子弧喷焊技术是以转移弧为热源,以合金粉末为喷焊材料的一种焊接工艺。它作为焊接技术的分支,由于具有母材冲淡率低、焊层整齐、工艺稳定以及易于实现自动化等特点,在提高材料表面性能,延长机械使用寿命方面发挥着越来越重要的作用。本文首先对等离子喷焊的原理作了介绍,其次主要对等离子喷焊机的送粉系统和喷焊枪结构进行了改进设计和分析。送粉系统方面采用了一种载气式滚轮送粉器进行定量送粉,通过气流喷吹和真空吸附组合方式的气力输送对喷枪进行送粉,解决了合金粉末比重较大难以输送的问题,使送粉的稳定性得到保证。为了验证此送粉系统的可行性,分别选用Co50粉末,超细WC复合粉末和Al2O3-Cr2O3粉末做了送粉实验,获得了理想的效果。并分析了滚轮转速、送粉气流量和真空吸附装置的尺寸对送粉速率的影响。喷焊枪设计方面对喷焊枪的喷吹口方式和水冷结构进行了改进,采用上下分离冷却,并对喷嘴进行了温度场分析。喷嘴是喷焊枪的关键部件,也是易损件,采用紫铜C15760制作,该材料具有高温高强度和良好的热稳定性。采用ANSYS12.0对容易烧损的喷嘴进行了有限元热分析,模拟了喷嘴在工况下的散热情况,得到了喷嘴的温度场分布图。并比较了不同冷却水速度对喷嘴散热的影响,得出了最佳冷却水速。最后从喷嘴结构和材料上提出改进措施,以增强喷嘴的散热性能,提高喷嘴的使用寿命。
[Abstract]:Powder plasma arc spray welding technology is a welding process with the transfer arc as the heat source and the alloy powder as the spray welding material. As a branch of welding technology, it plays a more and more important role in improving material surface performance and prolonging the service life of the machine because of its characteristics such as low base metal dilution rate, neat welding layer, stable process and easy realization of automation. Firstly, the principle of plasma spray welding is introduced. Secondly, the design and analysis of the powder feeding system and the welding torch structure of the plasma spraying welding machine are mainly improved. The powder feeding system adopts a pneumatic roller feeder to carry out the quantitative feeding. The pneumatic conveying is combined with the pneumatic suction and vacuum adsorption to deliver the powder to the spray gun, which solves the problem that the proportion of the alloy powder is large and difficult to transport, so that the stability of the powder feeding is guaranteed. In order to verify the feasibility of the powder feeding system, Co50 powder, ultrafine WC composite powder and Al2O3-Cr2O3 powder were used to do the powder feeding experiment, and the ideal effect was obtained. The influence of roller speed, powder flow rate and the size of vacuum adsorption device on the powder feeding rate was analyzed. On the design of injection pipe and spray gun to spray gun water cooling structure was improved by separating cooling, and the nozzle of the temperature field analysis. The nozzle is the key component of the spray welding gun. It is also a vulnerable part. It is made of copper C15760. The material has high temperature, high strength and good thermal stability. The finite element thermal analysis of the easily burned nozzle was carried out by ANSYS12.0. The heat dissipation of the nozzle was simulated and the distribution of the temperature field of the nozzle was obtained. The effect of different cooling water velocity on the heat dissipation of the nozzle is compared, and the optimum cooling water speed is obtained. At last, the improvement measures are put forward on the structure and material of the nozzle, in order to enhance the heat dissipation performance of the nozzle and improve the service life of the nozzle.
【学位授予单位】：武汉轻工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG43

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