Hard and Super Hard Coating Materials Used for Tribological Applications

Diamond like coating (DLC) and Cubic boron nitride (cBN) are the advanced coating materials used for coating automobile components and cutting tools. Diamond like coating are coated an coating thickness of 3 mm) on automobile components like camshafts, piston, piston rings , roller tappets, plungers (Common rail Diesel injection pump) and nano-composite materials by reactive magnetron sputtering method (PACVD) to increase the wear resistance properties by decreasing the friction, reduce CO2-emission and to improve fuel efficiency. Various test such as abrasive wear test (calo test), scratch test and Rockwell hardness test is carried out on coated components to check the properties of coating and results are enclosed, Reference [1]. Cubic boron nitride (cBN) coating materials are coated on cemented carbide and HSS tools to withstand high temperature stability, to increase wear resistance properties, increase the hardness of the cutting tool and to enhance longer life of the cutting tool. cBN layer of thickness (3 – 5mm) is deposited on the tool substrate at a temperature ≤ 650ºC by reactive sputtering system, and turning experiment is carried out on cnc inclined bed turning lathe by using the cBN coated tool, results are enclosed and it has been found that by coating cBN layer > 2 mm results in high potential for cutting tools, Reference [1 & 2].