A fabrication process for vacuum-deposited strain gauges on thermally sprayed Al₂O₃

Abstract

Electrically insulating films of Al2O3 were deposited using thermal spray technology followed by the sputter deposition of a strain gauge pattern using shadow masking techniques. For the first time, a thin film strain gauge of chromium was successfully fabricated on thermally sprayed Al2O3 insulation. X-ray diffraction (XRD), scanning electron microscopy (SEM) and profilometer characterization techniques were used to examine structure and surface morphologies of the Al2O3 coatings. A gauge factor of around 2 was found for chromium film as well as hysteresis and creep for loads exceeding 1700 micro strain. The results are discussed.

A fabrication process for CrN/TiAlN multi-layered strain gauges on mild steel

“…Mechanical masks with strain gauge pattern apertures were cut from 0.2 mm thick stainless steel shim using a Coherent AVIA 3ω Nd:YAG laser with two galvo mirror beam scanners. The mask preparation and laser parameters used were as described in a previous study [8]. Figure 1 shows the mask/substrate assembly that was used and coating layers that were deposited.…”

“…The greatest challenge for vapour deposited strain gauges on steel substrates is the preparation of a defect free, high quality electrically insulating film [8,9]. Cathodic arc evaporation can be used to deposit high quality insulators by evaporating from metal cathodes in a reacting gas.…”

Direct Fabrication of a Copper RTD over a Ceramic-Coated Stainless-Steel Tube by Combination of Magnetron Sputtering and Sol–Gel Techniques

“…Some authors have used thin-film layers to isolate a metallic substrate via reactive magnetron sputtering with SiO 2 and Al 2 O 3 [ 37 , 38 ], or YSZ/Al 2 O 3 multilayered films [ 39 ]. Others have used thermally sprayed alumina [ 40 ] and sol–gel deposition, or have applied Chemical Vapor Deposition (CVD) to fabricate SiO x films [ 41 ]. In this work, an advanced thick ceramic coating was applied.…”