Temperature Control for Friction Stir Welding of Dissimilar Metal Joints and Influence on the Joint Properties
Temperature Control for Friction Stir Welding of Dissimilar Metal Joints and Influence on the Joint Properties
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DOI：
10.4028/www.scientific.net/kem.767.360
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发表时间：
2018-04
期刊：
影响因子：
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通讯作者：
M. Krutzlinger;R. Marstatt;G. Costanzi;A. Bachmann;F. Haider;M. Zaeh
中科院分区：
文献类型：
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作者：
M. Krutzlinger;R. Marstatt;G. Costanzi;A. Bachmann;F. Haider;M. Zaeh
搅拌摩擦焊（FSW）是一种适用于铝与铜或铝与钛等异种金属的焊接技术。由于它是一种固态焊接工艺，通常不会超过固相温度，与熔焊工艺相比，金属间相的形成可以最小化。但在连接界面处仍形成金属间层。这一层决定了接缝的性能，如接缝强度或导电性。焊层厚度在纳米范围内，主要受焊接温度的影响，并遵循Arrhenius定律。加工温度主要取决于机床的转速和进给速度。本文研制了一种铝铜搭接温度控制系统。为此，采用PI控制系统通过调节转速来保持给定的焊接温度。因此，沿着整个焊缝确保了恒定的焊接温度，并且可以减轻工件几何形状、环境条件或材料变化等影响。为了验证所提出的恒定焊接条件，对一个典型焊接任务进行了6种不同温度水平（低、高）的实验。通过拉伸剪切试验、光学显微镜和电子显微镜对接头进行了研究。实验证明，温控FSW可以保证金属间化合物层厚度恒定。
Friction Stir Welding (FSW) is a suitable technology to join dissimilar metals such as aluminum and copper or aluminum and titanium. Since it is a solid state welding process, the solidus temperature is typically not exceeded and the formation of intermetallic phases can be minimized compared to fusion welding processes. However, an intermetallic layer is still formed at the joining interface. This layer determines the seam properties such as the joint strength or the electrical conductivity. The thickness of the layer is in the nanometer range and is mainly influenced by the welding temperature via an Arrhenius law. The process temperature mainly depends on the rotational speed and on the feed rate of the machine tool. In this study, a temperature control system for aluminum-copper lap joints was developed. A PI control system was used for this purpose to maintain the given welding temperature by adjusting the rotational speed. Consequently, a constant welding temperature was ensured along the entire seam and influences such as changes in workpiece geometry, environmental conditions, or material variations could be mitigated. Experiments with six different temperature levels (low – high) were conducted for one exemplary welding task in order to verify the proposed constant welding conditions. The joints were investigated by tensile shear tests as well as optical and electron microscopy. It was proven that temperature-controlled FSW ensures a constant thickness of the intermetallic compound layer.