Investigation of mechanical properties and oxidation resistance of CVD TiB2 ceramic coating on molybdenum

Abstract

TiB2 anti-oxidation ceramic coatings were successfully synthesised on a Mo substrate by using chemical vapor deposition (CVD). A scratch test was performed to measure the adhesion strength of the TiB2 ceramic coatings to the Mo substrate. The results indicated good adhesion between the two materials; the adhesion strength was 125 mN. Furthermore, high-temperature oxidation tests indicated that the CVD TiB2 ceramic coating protected the Mo substrate against oxidation up to 900 ℃. Isothermal oxidation experiments revealed that the Mo substrate covered with a 13-μm-thick TiB2 ceramic coating was protected against oxidation for a duration of 5 h. The oxidation kinetics followed a parabolic law for the first 2.5 h and a linear law in the next 2.5 h. Keywords: Titanium diboride, Coating, Chemical vapor deposition, Oxidation