Optimized Design for a Device to Measure Thermal Contact Conductance During Friction Stir Welding
Optimized Design for a Device to Measure Thermal Contact Conductance During Friction Stir Welding
复制标题
DOI：
10.1007/s10765-020-02746-0
复制
发表时间：
2020-10-27
影响因子：
2.2
通讯作者：
Munro, Troy
中科院分区：
文献类型：
--
作者：
Ellis, Daniel;Goodson, Matthew;Munro, Troy
搅拌摩擦焊（FSW）是一种固态焊接工艺，由于其能够以比熔焊更少的热输入产生高质量的焊缝，因此在各种行业中的使用越来越多。虽然FSW的建模已经进行了至少15年的积极努力，但两个输入参数，即摩擦系数和传热系数，仍然是难以测量的可调量。这种信息的缺乏损害了FSW模型的预测能力。虽然工具和工件之间的摩擦建模仍然是一项复杂的任务，但热传递的测量应该是可能的，但由于难以使用热电偶访问相关接口，因此尚未得到充分解决。本文提出了一种多层频域热反射法（FDTR）测量旋压模具与工件间传热系数的方法和传感器设计。由于焊接工艺的限制，需要多层结构用于可用的测量，以最大化从调制加热表面通过热传递界面进入焊接工件的热流。分析二维热四极模型被证明是有用的，在确定层的属性。使用COMSOL对特定刀具设计的多层结构进行了验证和优化。该过程可用于确定理想的传感器结构，以在摩擦搅拌焊接过程中最大化来自FDTR测量的信号。
Friction stir welding (FSW) is a solid-state welding process that is finding increasing use in a variety of industries, owing to its ability to create high-quality welds with less heat input than fusion welding. While the modeling of FSW has been an active effort for at least 15 years, two input parameters, namely the friction coefficient and the heat transfer coefficient, are still adjustable quantities that are difficult to measure. This lack of information compromises the predictive capability of FSW models. While the modeling of friction between the tool and workpiece remains a complex task, the measurement of heat transfer should be possible, but has not been adequately addressed because of the difficulty of accessing the relevant interface with thermocouples. This paper presents a multi-layered frequency-domain thermoreflectance (FDTR) method and transducer design to measure the heat transfer coefficient between the spinning tool and the workpiece. Due to constraints of the welding process, a multi-layered structure is needed for a useable measurement to maximize the heat flow from the modulated heating surface through the heat transfer interface into the welded workpiece. An analytical 2D thermal quadrupole model is shown to be useful in determining layer properties. A multi-layered structure for a specific tool design is validated using COMSOL and optimized. This process can be used to determine the ideal transducer structure to maximize the signal from an FDTR measurement during a friction stir welding process.