Wear Mechanism of Wear Resistant HVOF Thermal Spray Coating: Chromium Carbide Nickel Chrome on 304 AISI Steel

摘要

One of the common ways to overcome wear is by surface modification which is a coating process. The application of cermet of chromium (Cr carbide) in Nickel-Chromium (Ni-Cr) matrix is widely used as coating material since it provides high wear resistant. Besides, thermal spray process is widely known as the most suitable technique to produce cermet coating. In this study, chromium carbide-nickel chrome (Cr3C2- NiCr) powder is used as the feedstock. High Velocity Oxy Fuel (HVOF) thermal spraying is used to deposit the coating on mild steel substrate to study the behaviour of wear of the coating. The wear test is conducted by using TABER Linear Abrasion Wear Test machine. The wear rate of both coated and uncoated pin is measured by measuring the weight loss of the samples. The Cr3C2-NiCr coated pins have shown less weight loss than the uncoated pins. The lifetime prediction of Cr3C2-NiCr coated pins is higher than the uncoated pins at different time duration and applied loads. The results showed that the wear resistant properties of Cr3C2-NiCr coated pins are higher than the uncoated pins. Scanning Electron Microscopic (SEM) integrated with Energy-dispersive X-ray spectroscopy (EDS) are used to determine the microstructure of Cr3C2-NiCr coating. The microstructure of Cr3C2-NiCr coated pin after the wear testing showed no presence of crack and the wear track was homogenous.