Tribological Properties of Hybrid Process DLC Coating against Magnesium Alloy

The tribological properties of hybrid process DLC (Diamond-like carbon) coating against magnesium alloy are examined in order to understand the basic friction and wear properties of DLC coatings against magnesium alloy and partially to simulate the drawing process in real transfer press line. The tests are conducted using simple ball or pin on disc system with various combination of uncoated/DLC-coated WC-Co (cemented carbide) and AZ31B specimen in room/elevated temperature and dry/lubricated environments. As the result, DLC coating has excellent tribological properties against AZ31B magnesium alloy at 250/260°C, which is the actual hotworking drawing condition of AZ31B sheet, in both dry and lubricated environment. DLC coating prevents possible adhesion between AZ31B and WC-Co at elevated temperature in less lubricated or nearly dry contact condition.