Correlation of Surface and Interfacial Temperature During Differential Ultrasonic Spot Welding
Correlation of Surface and Interfacial Temperature During Differential Ultrasonic Spot Welding
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DOI：
10.1016/j.jajp.2023.100142
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发表时间：
2023-04
影响因子：
4.1
通讯作者：
Kaytie M. Barkley;Jaden S. Arner;T. Pike;P. Diwakar;Cassandra M. Birrenkott
中科院分区：
文献类型：
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作者：
Kaytie M. Barkley;Jaden S. Arner;T. Pike;P. Diwakar;Cassandra M. Birrenkott
超声波点焊已成为热塑性聚合物(TP)和热塑性基复合材料(TPMC)的一种极具吸引力的连接方法。在USW工艺中，要连接的材料受到高频机械振动，导致分子间和表面摩擦，从而在连接界面加热和熔化材料。界面重新定型，导致两种材质之间的连接。在USW中，有必要将机械振动集中在所需的焊接位置。实现这一点的一种常见方法是在材料之间的界面处加入能量指示器(ED)以优先熔化。然而，加入EDS会使制造过程变得复杂，特别是对于较大的恒厚聚合物片材。在这项工作中，使用了差动超声点焊(DUS)，它使用不同直径的平喇叭和砧座来在所需的连接位置处引发层板之间的摩擦加热。这项工作调查了DUS与更传统的USW设置的有效性。此外，通过在DUS过程中分别使用红外成像和热电偶(TC)测量表面和界面的温度，研究了焊接过程热分布背后的驱动因素。将热分布与DUS过程的物理属性相耦合的目的是最终确定热分布中存在的可变性是否可能与众所周知的关节面积和强度变化有关。
Ultrasonic spot welding (USW) has become an attractive joining method for thermoplastic polymers (TP) and thermoplastic matrix composites (TPMC). In the USW process, the material to be joined is subjected to mechanical vibrations of high frequency, causing intermolecular and surface friction which heat and melt the material at the joint interface. The interface resolidifies, resulting in a joint between two materials. In USW, it is necessary to focus the mechanical vibrations at the required weld location. A common method to accomplish this is to incorporate an energy director (ED) at the interface between materials to melt preferentially. However, incorporating EDs complicates the manufacturing process, particularly for large constant thickness polymer sheets. In this work, differential ultrasonic spot welding (DUS) is used which employs a flat horn and anvil of different diameters to initiate frictional heating between laminates at the desired joint location. This work investigates the effectiveness of DUS compared to a more traditional USW setup. Additionally, by measuring temperature at both the surface and the interface during DUS using infrared imaging and a thermocouple (TC), respectively, the driving factors behind the thermal profile of the welding process are examined. The goal of coupling the thermal profile to physical attributes of the DUS process is to eventually determine if variability present in the thermal profile may be tied to well-known joint area and strength variabilities.