Thermocouple Slip Ring Assembly For High Temperature Measurements in Electron Beam Physical Vapor Deposition Chamber

Thermal barrier coatings (TBCs) increase the thermal capability and enhance efficiency of gas turbines and jet engines. Their industrial and commercial importance has motivated researchers to investigate more effective material compositions. Extensive research has been conducted at UC Santa Barbara on TBC’s applied to substrates via electron beam physical vapor deposition (EB/PVD). Characterization of new TBC’s depends on many factors, one of which being temperature of application. Current temperature measurement technology implemented at UCSB uses a stationary thermocouple for substrate temperature measurements and is insufficiently accurate. The two main difficulties are due to the substrate’s necessity to be continuously spinning in order to have a uniform coating and the high operating temperatures during the EB/PVD process. Thus, the project goal is to design and create a thermocouple slip ring assembly that will allow temperature measurements to be taken with high accuracy in the EB/PVD chamber. A customized slip ring will be made using ceramics and the same material as the thermocouple leads, Chromel/Alumel. Doing so ensures the measurement signal is not distorted and minimizes errors produced from wire junctions. Completion of the project will allow researches gain valuable information that will advance their search for a improved alternative to modern TBC materials.