Apr 20th, 1:00 PM - 4:00 PM
Investigation of Residual Stress Induced Cracking in Thick TiOx Coatings
Dr. Peter Müllner
NxEdge remanufactures titanium oxide (TiOx) cylindrical sputter targets (C-Mag) for the architectural glass industry. TiOx is sputtered onto glass substrates to reduce UV transmission and resist scratching. The rotating C-Mag target is advantageous to glass manufacturers because it allows for longer deposition times. Remanufacture is accomplished by thermally spraying new TiOx onto used target substrates; unfortunately, a significant number of NxEdge’s TiOx targets crack after manufacture. Axial cracking of the TiOx indicates residual stress between the structural stainless steel substrate and the TiOx coating. As part of this work, hardness and porosity were evaluated for TiOx samples exposed to different processing histories in an attempt to correlate change in properties and microstructure to component reliability. Additionally, a battery operated strain gauge capable of in-situ measurements of strain has been developed. The design and preliminary testing of the strain gauge is presented.