COMPARISON THE VANADIUM CARBIDE COATING CREATED VIA PLASMA ELECTROLYTIC SATURATION AND TERMO REACTIVE DIFFUSION

Abstract

One of the most important hardening methods of tool steel is the use of carbide coatings, in which during this process, vanadium diffuses to the specimen’s surface and reacts with carbon. During the Plasma Electrolytic Saturation (PES) Process, the vanadium element diffuses with the help of plasma and increases up to around 1000°C as a result of the temperature, providing conditions for the creation of vanadium carbide. On the other hand, the thermo reactive diffusion (TRD) method during which the specimen is placed inside a salt bath containing the vanadium for a long period of time and the vanadium carbide coating is formed. In this paper, an attempt is made to study the formed coating with the method of plasma electrolytic saturation in addition to comparing the coatings formed by these two methods and obtain some vanadium carbide that created with TRD is purer than PES but that is thinner than plasma method, hardness of coating that created with TRD is about 2500 HV but in TRD is 1100 HV finally. In some PES samples the temperature increase slowly and the maximum temperature is about 120°C, in this condition, the coating is non- diffusion. The hardness of PES coating is about 1100 HV so we can use that in industrial molds.