Laser cladding of iron-base alloy on Al-Si alloy and its relation to cracking at the interface

The present study established the basic operating range and diagram for cladding, by means of a laser, a cast Al-Si alloy substrate with an iron-base material, Considering that the main difficulty was interface cracking during this processing, the factors affecting the interface cracking ratio (ICR) were investigated from two aspects: the laser processing parameters (e.g., laser power, traverse speed, powder-feed rate, preheating temperature of the substrate, tempering temperature) and the material factor, including the composition of clad. The substrate temperature and the tempering temperature were found to be important for controlling ICR, and the content of Al and Ni in the clads also had significant influence on ICR. The intermetallic compounds formed in the interface region were analyzed to understand the effect of Ni content on ICR. Clads of thickness from 1.2 to 1.5 mm that were crack free and had good fusion were achieved by controlling the substrate temperature or adjusting the Al content in the clads.