Optimisation of HVOF Spray Process Parameters to Achieve Minimum Porosity and Maximum Hardness in WC-10Ni-5Cr Coatings

Abstract

High-velocity oxy-fuel (HVOF) spray coating plays a major role in many surface treatment methods, which tend to improve erosion and corrosion resistance properties. HVOF is well known for its dense and high-quality coating ability. This is due to the less in-flight exposure time, which tends to have less oxide content because of its high-velocity properties. Among the number of process parameters, porosity and hardness are predominant factors while considering wear rate and corrosion behaviour analysis. The current study aims to optimise HVOF process parameters to obtain low levels of porosity and high hardness values in the WC-10Ni-5Cr coating sprayed on 35 Mo Cr steel. The flow rates of oxygen, LPG, coating powder feed rate and spray distance are selected in this study as these have a superior influence on the final condition of the coating. Statistical tools such as the design of experiments (DoE), analysis of variants and response surface methodology (RSM) were used to achieve the desired results. As per the result analysis, the oxygen flow rate has a higher effect on the porosity value and microhardness value of the coating.

Influence of Post-Heat Treatment on the Characteristics of FeCrBMnSi Coating on Stainless Steel 304 Substrate Prepared by Twin Wire Arc Spray (TWAS) Method at Various Stand-off Distance

“…Percentage) and maximum hardness (1325.26 HVx) [53]. Furthermore, a study found that the presence of the lowest porosity causes the Fe-based amorphous coatings to have the highest hardness [50]. These findings show that decreasing porosity leads to an increase in coating hardness.…”

“…Porosity causes inadequate coating cohesion and reduces the ability to endure indentation loads, resulting in a decrease in hardness. Furthermore, porosity in the coating can result in rising corrosion rates and wear [50]- [52]. The porosity of a coating is inversely related to its hardness.…”

Optimization and Fabrication of Binder-Free Nickel-Copper Phosphate Battery-type Electrode Using Microwave-Assisted Hydrothermal Method

“…The determination coefficient (R 2 ) is the measurement to determine the goodness of fit of the model. 60,61 The R 2 value always lies between 0 and 1, and a value higher than 0.75 represents a good fit for model. 62 The R 2 of the model showed a value of 0.9942, which was higher than 0.75, indicating the obtained results were well-matched with model prediction.…”

Optimizing Friction Welding Parameters in AISI 304 Austenitic Stainless Steel and Commercial Copper Dissimilar Joints

“…Surface plots and contour plots, which are indicators of potential independence of variables, have been established for the proposed empirical relation by taking into account two variables in the middle level and two variables in the x-and y-axes in order to obtain the affecting nature and optimized condition of the process on the UTS. The prediction of the response (UTS) for any zone of the experimental domain can be assisted by these response contours [34].…”