ČESÁNEK Zdeněk VZU Plzeň

Spoluautoři HOUDKOVÁ Šárka, SCHUBERT Jan, KAŠPAROVÁ Michaela

HVOF (High Velocity Oxygen Fuel) thermal spraying technology is commonly used for component surface protection against abrasive wear. Alloy- and cermet-based coatings meet demands on high abrasive wear resistance. Wear resistance is in many cases decisive property for proper component functioning. The suitable materials for particular applications are usually selected according to their different hardness. From this reason, the present work is focused on comparison of abrasive wear resistance and hardness of alloy- and cermet-based coatings. The coatings sprayed on steel substrates were subjected to the abrasive wear test according to modified method ASTM G-65 (Rubber Wheel/Dry Sand Abrasion Test). Abrasive sand Al2O3 with grain size (212-250) µm was used. Stellite 6, NiCrBSi, CrC-NiCr, CrC-CoNiCrAlY, WC-Co powders were used to prepare sample sets subjected to the test. It is shown, that the abrasive wear resistance is not directly proportional to the hardness. The difference in microstructure between cermets and alloys coatings in relation to wear mechanism plays the essential role.