搅拌摩擦焊隔热搅拌头研究

发布时间：2018-03-18 22:03

  本文选题：搅拌摩擦焊　切入点：隔热搅拌头　出处：《浙江理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：搅拌摩擦焊是一种焊接过程中被焊材料不发生熔化的固相焊接技术,具有能量利用率高、焊接过程不产生有害气体、不产生废料等优点,并解决了传统熔焊易产生焊接缺陷、焊接接头强度低等缺点,其尤其适合用于焊接如铝合金、镁合金等硬度及熔点较低的金属。目前针对搅拌摩擦焊的研究主要集中在焊接工艺参数的优化设计、搅拌头设计、焊接过程中材料流动机理、产热机理,以及其对被焊材料组织和性能的影响等方面。本文利用实验和计算机模拟相结合的方式研究搅拌摩擦焊接过程中搅拌头向主轴方向的传热,设计制作隔热搅拌摩擦焊接搅拌头,减少焊接过程中搅拌头向主轴的传热,降低主轴温度,同时减少焊接时的热损耗,提高焊接热效率。本文借助有限元数值模拟,设计了一种有利于减少传热的新型搅拌头结构,并采用等离子喷涂法对搅拌头夹持柄部位喷涂Y2O3稳定的Zr O2热障涂层减少其向主轴方向传热,分别使用常规搅拌头和本研究所设计的隔热搅拌头对5mm厚6061-T6铝合金板进行焊接实验,测量焊接过程中搅拌头、机床主轴以及焊接试板的温度场,研究隔热搅拌头的隔热效果并计算焊接热效率。实验结果表明,在搅拌头旋转速度800 r/min,焊接速度30 mm/min的情况下,使用常规搅拌头焊接主轴外表面稳态温度最高为82.8℃,使用隔热搅拌头最高为43.1℃,温度降低显著,有限元数值模拟结果表明,在以上条件下,使用常规搅拌头焊接向主轴方向传热功率为88.4W,使用隔热搅拌头传热功率42.2W,传热量减少逾50%;在搅拌头旋转速度800 r/min,焊接速度200 mm/min的情况下,使用常规搅拌头焊接焊核区最高温度约430℃,使用隔热搅拌头焊核区最高温度约460℃,温度提升30℃左右,使用常规搅拌头向上传热功率84.8W,使用隔热搅拌头向上传热功率43.3W,此时常规搅拌头焊接热效率为92.2%,隔热搅拌头热效率为96.0%,热效率提升3.8%。本文还通过有限元模拟对将隔热搅拌头设计用于钢材焊接时可能产生的效果做了初步探讨,模拟结果认为搅拌头隔热可使钢材搅拌摩擦焊主轴温度大幅下降,使其焊接热效率得到显著提升。
[Abstract]:Friction stir welding (FSW) is a kind of solid phase welding technology in which the welding material is not melted. It has the advantages of high energy utilization, no harmful gas and no waste in the welding process. It is especially suitable for welding metals with low hardness and melting point such as aluminum alloy, magnesium alloy, etc. At present, the research on friction stir welding mainly focuses on the optimization design of welding process parameters and the design of stir head. Material flow mechanism, heat generation mechanism, In this paper, the heat transfer of the friction stir welding head to the main axis is studied by means of the combination of experiments and computer simulation, and the heat insulation friction stir welding stir head is designed and manufactured. The heat transfer from the mixing head to the spindle is reduced, the temperature of the spindle is reduced, and the heat loss during welding is reduced, and the welding heat efficiency is improved. In this paper, a new type of mixing head structure is designed with the help of finite element numerical simulation, which is helpful to reduce heat transfer. Plasma spraying method was used to spray Y _ 2O _ 3 stabilized ZrO _ 2 thermal barrier coating on the clamping handle of mixing head to reduce heat transfer in the direction of main axis. The welding experiments of 6061-T6 aluminum alloy plate with 5mm thickness were carried out by using the conventional mixer and the heat insulation mixer designed by our institute. The temperature field of the mixing head, the spindle of the machine tool and the welding test plate during the welding process were measured. The heat insulation effect of the heat insulation mixer was studied and the welding heat efficiency was calculated. The experimental results show that the highest steady state temperature of the outer surface of the spindle welded by conventional mixing head is 82.8 鈩，

本文编号：1631496