Abstract:

High Velocity Oxygen Fuel (HVOF) is one of the excellent approaches used to coat lamellar graphite cast irons with wear-resistant Cr3C2-25%NiCr Chromium Carbide-Nickel Chrome and WC-12%Co tungsten carbide with good qualities. In this research, -45 +5 μm Cr3C2-25%NiCr and WC-12%Co sintered powder is used to coat the surfaces of the brake discs, which are made of lamellar graphite cast iron, that contact with the pads.  Performance of the discs, which are covered with these powders, in terms of wear and braking characteristics are studied. The microstructure of the Cr3C2-25%NiCr and WC-12%Co coating, which is applied by using the HVOF spraying method, is characterized at each step by scanning with electron microscopy. Braking performance and coated surface wear testing is performed with SAE J2430, TS 555 and TS 9076 brake-on-disk tester. Wear mass loss values are examined by applying different loads at the sliding distance. Test results show that the amount of wear of the coated sample is reduced in comparison to the uncoated sample. As a result of this study, the effects on the microstructure, mechanical properties and abrasive wear behaviour of coatings deposited by using the Cr3C2-25%NiCr and WC-12%Co powder and an ethane-fuelled, high-velocity oxygen-fuel spray process are revealed.

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