High temperature sensor assembly

许多工业工厂和发电设施将受益于在关键位置安装超声波传感器，以监测危险条件，如因腐蚀而导致的墙体变薄。这种传感器必须承受高达700摄氏度的温度。现在有了能够承受这种温度的传感器组件，但将这些组件连接到一个功能单元中会带来一个问题：界面热应力会导致键合线失效，因为每个传感器组件在温度升高时会以不同的速度膨胀。在本项目中，我们针对与我们的工业合作伙伴的需求相关的特定材料和温度范围(20-700摄氏度)，开发了一种粘合协议来解决这个问题。将为每个候选材料确定最佳固化周期、焊接线厚度和装配顺序。用每种粘结剂制成的换能器原型将在感兴趣的整个温度范围内进行物理强度和超声波性能评估。将通过扫描电子显微镜对接合线横截面进行破坏性检查，以评估不成功的接合操作的失败机制，以帮助开发解决方案。提交给工业合作伙伴的最终解决方案将是推荐的粘结剂、相关的固化周期、装配细节(包括任何辅助操作的夹具)以及测试计划的详细结果。

Many industrial plants and electrical power generation facilities would benefit from having ultrasonic sensors installed at critical locations to monitor for hazardous conditions such as wall thinning from corrosion. Such sensors must endure temperatures of up to 700 degrees Centigrade. Transducer components capable of withstanding such temperatures are now available, but bonding the components together into a functional unit poses a problem: interfacial thermal stresses cause the bond lines to fail, because each transducer component expands at a different rate as its temperature is raised. In this project, we develop a bonding protocol to address this issue, targeted towards the specific materials and temperature range (20 - 700 C) that are pertinent to the needs of our industrial partner.The bonding agents that are candidates for this task are six industrial adhesive agents and braze materials. An optimal curing cycle, bondline thickness, and assembly sequence will be determined for each candidate. Transducer prototyppes made with each bonding agent will be assessed for physical strength and ultrasonic performance over the full temperature range of interest. Destructive examination of the bondline cross section will be carried out by Scanning electron Microscope to assess the failure mechanism of unsuccessful bonding operations to aid in developing a solution. The final solution to be delivered to the industrial partner will be the recommended bonding agent, the associated curing cycle, assembly details including any jigs to aid the operation, and detailed results of the testing program.