Thermal spray is an effective process for the fabrication of a metal matrix composite (MMC), where a zirconium diboride reinforcement is embedded in a molybdenum matrix to enable the combining of favorable properties in a new composite. The combination of two leading materials in the category of ultra-high-temperature ceramics (UHTCs) is due to a very high melting point (Mo: 2623 °C and ZrB2: 3245 °C), high thermal conductivity (Mo: 139 W/m°C and ZrB2: 24 W/m°C), good thermal shock resistance, low coefficient of thermal expansion (Mo: 5.35 µm/m°C and ZrB2: 5.9 x 10-6 K-1), retention of strength at elevated temperatures and stability in extreme environments. Thermal spraying of the Mo/ZrB2 composite possesses a non-linear behavior that is influenced by many coating variables. This characteristic makes finding the optimal factor combination difficult. Therefore, an effective and strategic statistical approach incorporating systematic experimental data is needed to optimize the process. In this study, the L9 orthogonal array in the Taguchi approach was utilized to optimize the spraying distance (SD), number of passes (NP), pressure (P) and coat-face temperature (TCF) using a dummy fiberglass substrate. The performance was evaluated based on the coating density (Cd) of the surfaces. Based on confirmation tests, our Taguchi analysis determined the ideal process parameters, which considerably enhanced the coating process. From the output response of the ANOVA, the most influential parameters for achieving a high coating density (Cd) were determined to be SD = 20 cm, NP = 24, P = 4 bar and TCF = 330 °C ((SD.)1-(NP.)3-P2-(S.T.)3). These observations show that the coating density (Cd) was significantly influenced by the coat-face temperature, followed by the number of passes, spraying distance and pressure with the following contributions 6.29, 17.89, 17.42 and 3.35%, respectively.

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Different parameters primarily influenced the spray process. Table 1 shows the parameters and their levels that were used in this study. The main process variables affecting the in-flight particle temperature and velocity were the fuel flow, spraying distance and oxygen flow. In addition, the porosity and corrosion resistance of the coatings were significantly impacted by the spray distance [8].

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Surface Smoothness and Hardness:Longer spraying distances result in smoother and cleaner coatings, enhancing the aesthetic and functional surface properties.

Coating Thickness and Porosity:Increasing the number of passes during the TS process results in a thicker coating, which can provide better protection and durability.

Particle Velocity and Kinetic Energy:Increased oxygen and acetylene fuel rates elevate particle velocity, improving the coating'ss density and bonding strength. This ensures a more uniform and cohesive coating layer.

Enhanced Performance:Surface modification through TS coatings significantly improves the performance of engineering components by providing superior wear resistance, corrosion resistance, and thermal insulation.

Cost-Effectiveness:TS coatings allow for the use of less expensive base materials by enhancing their surface properties, leading to cost savings in material selection and replacement.

Adaptability to Harsh Conditions:TS coatings are ideal for environments with corrosive elements, high wear rates, or extreme temperatures. This adaptability makes them suitable for a wide range of industries, including automotive, aerospace, and energy.

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The difference between the experimental data and the targets was converted by Taguchi's loss function into a S/N ratio, or a ratio of the mean to standard deviation. Taguchi employs a signal and noise to symbolize the desired and unwanted values for the response. In order to get the S/N ratio, Equation (1) was employed, and the obtained results are shown in Table 4. The S/N ratio was separated into three groups based on the desired level of response: the-medium-the-better, the-larger-the-better and the-lower-the-better [22]. The larger-the-better level of the Cd was characteristic of the responses in this study.

Growing Industrial ApplicationsThermal spray coatings are crucial for enhancing surface properties such as wear resistance, corrosion resistance, thermal insulation, and fatigue resistance. Industries with demanding operating conditions, like aerospace and automotive, increasingly rely on these coatings for critical components.

Material AdvancementsWith the development of new materials like yttria-stabilized zirconia (YSZ) and molybdenum coatings, TS processes are gaining traction. These materials provide superior thermal stability, corrosion resistance, and wear resistance, essential for high-performance applications.

Optimization of Process ParametersThe optimization of TS process parameters, such as spraying distance, gas pressure, and coat-face temperature, directly impacts the quality of the coatings. The use of methodologies like Taguchi techniques for process optimization can significantly improve coating properties, leading to higher adoption rates in industries that require precision and reliability.

Economic BenefitsTS coatings enable the use of cheaper base materials by improving their surface properties, offering economic benefits. This cost-effectiveness is particularly attractive in industries where material costs are a significant concern.Innovative Applications

Research and DevelopmentContinuous research and development in optimizing TS process parameters and exploring new coating materials will further enhance the market potential. The ongoing studies to understand the effects of TS process parameters on microhardness and other properties will likely lead to improved performance and broader application scopes.