2007 年 48 巻 553 号 p. 156-160
The frictional behaviour of magnesium alloy AZ31B (Mg-3%Al-1%Zn) is evaluated by a tapered plug penetration test under dry conditions. The cemented tungsten carbide (WC) plugs, polished to exhibit a mirror-like surface, are coated with diamond-like carbon (DLC) and TiAlN by physical vapor deposition (PVD). The cylindrical hollow billets of AZ31B heated to a temperature of 200 °C are penetrated by the tapered plugs. Coating a tool with DLC is effective in preventing AZ31B from adhering to the tool surface. To examine the deformation behaviour of the billet during plug penetration, finite element simulation is carried out. From the simulation and experimental results, the coefficients of shear friction of WC-AZ31B and DLC-AZ31B are estimated to be about 0.30 and 0.25, respectively.