Effect of High-Speed Powder Feeding on Microstructure and Tribological Properties of Fe-Based Coatings by Laser Cladding

Abstract

In order to improve the wear resistance of 27SiMn steel substrate, Fe-based alloy coatings were prepared by laser cladding technology in the present study. In comparison to the conventional gravity powder feeding (GF) process, high-speed powder feeding (HF) process was used to prepare Fe-based alloy coating on 27SiMn steel substrate. The effect of diversified energy composition of powder materials on the microstructure and properties of coatings were systematically studied. X-ray diffractometer (XRD), optical microscope (OM) and scanning electron microscope (SEM) were used to analyze the phase structure and microstructure of Fe-based alloy coatings, and the hardness and tribological properties were measured by the microhardness tester and ball on disc wear tester, respectively. The results show that the microstructure of conventional gravity feeding (GF) coatings was composed of coarse columnar crystals. In comparison, owing to the diversification of energy composition, the microstructure of the high-speed powder feeding (HF) coatings consists of uniform and small grains. The total energy of the HF process was 75.5% of that of the GF process, proving that high-efficiency cladding can be achieved at lower laser energy. The refinement of the microstructure is beneficial to improve the hardness and wear resistance of the coating, and the hardness of the HF coating increased by 9.4% and the wear loss decreased to 80.5%, compared with the GF coating. The wear surface of the HF coating suffered less damage, and the wear mechanism was slightly adhesive wear. In contrast, wear was more serious in the GF coating, and the wear mechanism was transformed into severe adhesive wear.

Improvement of Microstructure and Properties of Q235 Steel by Iron-Based Laser Cladding Coating

“…e amorphous shape and low interface energy of amorphous alloy powder provide good wettability properties to the matrix material. Moreover, it melts uniformly during cladding [9][10][11][12][13].…”

Wear performance of FeCuMoTiV high entropy alloy coatings by laser cladding

“…The methods of preparing high-entropy alloy coatings include laser cladding, plasma cladding, magnetron sputtering, plasma spraying, etc Among them, laser cladding is the most effective means of preparing large-area coatings, which has been widely used in surface modification of materials [21][22][23]. Highentropy alloy coatings prepared by laser melting and cladding usually exhibit good metallurgical bonding and slight dilution with the substrate, which is favorable for engineering applications [24][25][26][27].…”

Microstructural Evolution, Hardness and Wear Resistance of WC-Co-Ni Composite Coatings Fabricated by Laser Cladding

“…Laser cladding achieves good metallurgical bonding, lower dilution of the cladding layer, and lower distortion than conventional methods, such as arc welding and thermal spraying [12,13], but involves rapid temperature changes, which affect the mechanical properties and dimensional stability of the cladding layer. These rapid temperature changes can finally cause excessive heat-affected zones, cracks, and pore defects [14][15][16].…”