Deposition of a TiC/Ti coating with a strong substrate adhesion using a high-speed plasma jet

Abstract

Titanium carbide coatings have many applications due to their large number of useful properties such as the increase of the resistance to wear, corrosion, and oxidation of the substrate. However, poor adhesion of TiC coatings to metal substrates is known as one of the main problems. This paper shows the possibility of depositing TiC/Ti coating with a thickness of 10 to 30 μm on copper substrates using a high-speed plasma jet, which is generated by a coaxial magneto-plasma accelerator. The formation of cubic titanium carbide with a small amount of pure titanium is confirmed by XRD and SAED results. EDX analysis indicates both the presence of an intermixing zone near the boundary between the substrate and coating, where their particles mix together during the crystallization process, and the deep penetration of titanium particles into the substrate structure due to the high speed of the plasma flow (~ 3 km/s). These processes lead to the formation of a coating with a strong adhesion to substrate. The critical adhesion strength is equal to 5200 MPa. However, the presence of pure titanium particles influences the hardness of the coating, slightly decreasing the coating hardness to ~ 1900 HV and increasing the hardness of the substrate top layers up to 95 HV.