High temperature sensor assembly

点击翻译按钮获取中文摘要

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.