Microstructure And Wear Resistance Of Al_xCrFeCoCu_yNi High Entropy Alloy Coating By Argon Arc Cladding

The high entropy alloy that has been widely concerned breaks through the shackles of traditional alloy design theory,and is widely concerned and studied for its simple structure and excellent properties.High-entropy alloy coating can effectively improve the surface properties of metal materials,and can further broaden the scope of use of metal materials.In this study,Al_xCrFeCoCu_yNi（x=0,0.5,1.0,1.5,2.0,2.5,y=0,0.2,0.2,0.2,0.4,0.6,x,y is molar ratio）high wear-resistant and high entropy alloy coating was prepared using Al,Cr,Fe,Co,Cuand Ni metal powders as raw materials and argon arc cladding technology.With the help of metallographic microscopy,scanning electron microscope,X-ray diffractometer,microhardness meter,friction and wear testing machine and other instruments,the influence of argon arc cladding process parameters and Aland Cuelement content on the coating microstructure and properties of Al_xCrFeCoCu_yNi high entropy alloy was studied.Based on the calculation of the parameters of mixed enthalpy,mixed entropy,valence electron solubility and atomic radius difference of the alloy system,the coating composition of AlCrFeCoCuNi high entropy alloy is designed.By adjusting the argon arc cladding process parameters to regulate the microhardness and forming effect of the coating,the coating coating is 110 A,the argon flow rate is 10 L/min,the cladding speed is 8 mm/s,and the preset coating thickness is 1.2 mm,and the coating is relatively flat,the microhardness is high,and the combination of the coating and the matrix is metallurgically combined.In order to improve the wear resistance of the coating,the effect of Alcontent on the microstructure and properties of The AlCrFeCoCuNi high entropy alloy coating was studied.When the Almolar ratio is between 0 and 0.5,the coating is FCC crystal structure,with the increase of Alcontent,the coating crystal structure is transformed by the FCC phase BCC phase,and the Almolar ratio is 1.0～2.0,the coating is composed of FCC,BCC1,BCC2phases When the Almolar ratio exceeds 2.0,the coating is composed only of the BCC phase;the coating microstructure is composed of isometric crystals and gray grain boundaries,and with the increase of The Alcontent,the structure has a tendency to refine;the wear resistance of the coating increases with the increase of the Alcontent,and when the Almolar ratio is 2.5,the wear resistance of the coating is nearly 10 times higher than that of the matrix,and the wear mechanism of the coating transition from adhesive wear to abrasive wear.However,when the Almolar ratio exceeds 1.5,the Al_xCrFeCoCuNi high entropy alloy coating undergoes a tough and brittle transformation,so the Almolar ratio of 1.5 is used as the optimal ratio for the Al_xCrFeCoCuNi high entropy alloy coating.In order to further improve the wear resistance of the coating,the content of Cuelement is optimized,and the addition of Cuelement is conducive to generating a strong FCC phase to prevent the coating from cracking.When the Cumolar ratio is 0-0.2,the coating performance is better wear resistance,the microhardness of the coating decreases with the increase of the Cumolar ratio,while the friction coefficient gradually increases,and the wear resistance is gradually reduced,where the Cumolar ratio is 0,the microhardness is 808 HV_0.5,the friction coefficient is only about 0.34,and the wear resistance is nearly 15.5 times higher than that of the substrate.However,when the Cumolar ratio is 0,the coating undergoes a tough and brittle transformation,so the Cumolar ratio of 0.2 is used as the optimal ratio for Al_1.5CrFeCoCu_yNi high entropy alloy coatings.Finally,Al_1.5CrFeCoCu_0.2Ni high entropy alloy coating was obtained,which has the best comprehensive performance and can be used as the optimal ratio for the modification of argon arc cladding on the surface of 45 steel.