Microstructures and Properties of Laser-Cladded FeCoCrNiAlTi High-Entropy Alloy with Intensive Repair Potential

As a key step in intensive additive repair, the design of intensive repair materials immediately needs to be explored. In this work, an intensive additive repair study based on laser cladding technology was performed using a self-designed Fe20Co25Ni31Cr8Al9Ti7 high-entropy alloy (HEA) powder and three types of substrates widely used in field equipment (namely, Q235, 17CrNiMo6H, and 304 stainless steel). The results revealed that the HEA repair layer (HEA-RL) consists of a dominant FCC phase and a small amount of BCC phase, and the microstructure shows the columnar-to-equiaxed grain transition behavior. The metallurgical bonding between the HEA-RL and the three substrates has almost no defects. Compared with the three substrates, the HEA-RL has a much higher microhardness (~340 HV) and decent corrosion resistance. Therefore, the underlying mechanisms for the microstructure and performance of the HEA-RL were also discussed. This work provides a new idea for the design of intensive repair materials.