The Influence of high temperature exposure on the wear of selected HVOF sprayed coatings

Vliv vysoké teploty na mechanické vlastnosti a opotřebení HVOF stříkaných povlaků na bázi CrC a Ni/Co slitin byl hodnocen pomocí měření mikrotvrdosti, kohezní pevnosti, odolnosti proti abrazivnímu a adhezivnímu opotřebení. Bylo zjištěno, že povlak na bázi Stellite 6 vlivem působení vysoké teploty degraduje, zatímco povlaky na bázi NiCrBSi a CrCNiCr z tepelného ovlivnění profitují.The influence of high temperature exposure on the mechanical and wear properties of selected HVOF sprayed CrC and No/Co – based alloy coatings were tested. Comparison of as-sprayed and 600°C/116 h annealed coatings’ microhardness, cohesive strength, abrasive and adhesive wear resistance showed that the Co-based Stellite 6 coating’s wear properties were deteriorated by heat exposure despite of the increase of its hardness and cohesive strength. The heat exposure was found to be beneficial for both mechanical and wear properties of NiCrBSi self-fluxing coating. On the contrary, mechanical properties of Cr3C2-NiCr coating slightly decreased, while its wear resistance slightly increased as a result of high temperature exposure