This paper aims at developing an empirical relation to predict the porosity and micro-hardness, by means of High Velocity Oxy Fuel (HVOF) sprayed WC-10Co-4Cr coatings. For determining the coating performance, process parameters such as flow rate of LPG fuel, flow rate of oxygen, spray distance, flow rate of carrier gas and feed rate of the coating powder play a significant role. Five-factors, five-level central composite rotatable design (CCD) was employed in this analysis to reduce the number of experiments by covering all possible combinations of the process variables. A mathematical model was established to assess the porosity and microhardness of the coatings including HVOF process parameters and the appropriateness of the model was examined using analysis of variance. Using RSM, process parameter optimizations were conducted. The coatings produced using optimized process variables had a minimum porosity level of 0.2 Vol. percentage and a maximum hardness of 1325.26 HV_x compared to other coatings. This has been confirmed by the developing response graphs and also by plotting contours. The optimization of HVOF parameters using RSM, as well as the correlation of spray variables with properties of the coating, enables the recognition of the framework of the characteristics to attain the preferred consistency of WC-10Co-4Cr coatings. Analysis of Sensitivity is also performed to determine the most significant process parameter for the HVOF operation.

本文旨在通过使用高速氧燃料 (HVOF) 喷涂 WC-10Co-4Cr 涂层开发一种经验关系来预测孔隙率和显微硬度。对于决定涂层性能，LPG 燃料流量、氧气流量、喷涂距离、载气流量和涂层粉末进料速度等工艺参数起着重要作用。在该分析中采用了五因素、五级中央复合可旋转设计 (CCD)，通过涵盖过程变量的所有可能组合来减少实验次数。建立数学模型来评估涂层的孔隙率和显微硬度，包括 HVOF 工艺参数，并使用方差分析检查模型的适用性。使用 RSM，进行了工艺参数优化。使用优化的工艺变量生产的涂层的最小孔隙率为 0.2 Vol。百分比和最大硬度 1325.26 HV_x与其他涂层相比。这已被开发的响应图和绘制的等高线所证实。使用 RSM 优化 HVOF 参数，以及喷涂变量与涂层性能的相关性，能够识别特征框架，以获得 WC-10Co-4Cr 涂层的优选一致性。还执行灵敏度分析以确定 HVOF 操作的最重要的工艺参数。