Simulation and experiment of laser cladding layer for repairing brake disc in heavy-duty vehicles.

The damage to brake discs in heavy-duty vehicles caused by uneven wear is usually repaired with milling method, which reduces their radius and accordingly shortens their service life. Laser cladding repair can maintain the radius, thereby gradually becoming a promising method for brake disc repair, but the complexity of the laser cladding process causes the cladding layer to generate defects that decrease the repair quality. Here, we studied the regulation mechanism of laser power, beam diameter and scanning speed in the cladding layer's quality via simulation and experiment. Simulation results showed that with the increase of laser power and the decrease of beam diameter or scanning speed, the molten pool's temperature and flow rate, and the cladding layer's residual stress have varying degrees of increase. We then fabricated laser cladding samples (Ni60/WC on ductile iron) and acquired their micromorphology, dilution rate and microhardness, and analyzed their regulation mechanism. Experiment results exhibited that the cladding process with laser power 1400 W, beam diameter 3 mm and scanning speed 10 mm/s can make the cladding layer have a better quality. This study provides an available reference for the laser cladding repair of uneven wear in brake discs from heavy-duty vehicles.