This book provides a comprehensive review of the effects of key factors ranging from powder characteristics to process parameters, substrate preparation, and post-treatment methods on the coated substrate surface by different thermal spray techniques. Thermal spray techniques have gained significant attention in various industries due to their ability to deposit protective coatings on substrates. These coatings enhance the surface properties of substrates, such as wear resistance, corrosion resistance, and thermal insulation. However, the quality and performance of the coated substrate surface are influenced by several key factors. The book discusses the influence of parameters such as powder characteristics, process parameters, substrate preparation, and post-treatment methods on the coating microstructure, adhesion, and overall performance. The review aims to contribute to a better understanding of the factors that affect the coated substrate surface and provide insights for future research and optimization of thermal spray processes.