Study on mechanical properties of nickel-based tungsten carbide cladding layer based on plasma cladding process

Abstract

The Ni60+60%WC cladding layer was prepared on the surface of Q355 steel by plasma cladding process under different cladding currents. Through a metallographic microscope, microhardness test, shear strength test, and friction and wear test, the relationship between solidification structure and mechanical properties of Ni60+60%WC cladding layer was analyzed. Through experiments, it is concluded that when the current is 150-170 A, there is a good metallurgical bond between the cladding layer and matrix, and the bonding effect improves with the increase of the cladding current. The metallurgical bonding effect is poor when the current is 130 A or 140 A. When the cladding current is high, the hard tungsten carbide particles in the cladding layer show varying degrees of sinking phenomenon. Simultaneously, with the escalation of the cladding current, the tungsten carbide (WC) particles within the cladding layer decrease in size, and the ablation phenomenon becomes more obvious. When the cladding current is 130-160, the hardness of the obtained cladding layer increases to varying degrees compared to the matrix, with the highest hardness obtained with a current of 160 A. With an increasing distance from the cladding layer surface, there is an observed trend of hardness initially increasing and subsequently decreasing. In addition, as the cladding current goes up, the shear strength of the cladding layer goes down. The trend of abrasive resistance of cladding layers is the same as that of hardness. The abrasive resistance of the cladding layer increases with the increase of hardness.