Thermal spray coatings are material systems with unique structures and properties that have enabled the growth and evolution of key modern technologies (i.e., gas turbines, structurally integrated components, etc.). The inherent nature of these sprayed coatings, such as their distinctive thermal and mechanical properties, has been a driving force for maintaining industrial interest. Despite these benefits and proven success in several fields, the adoption of thermal spray technology in new applications (i.e., clean energy conversion, semiconductor thermally sprayed materials, biomedical applications, etc.) at times, however, has been hindered. One possible cause could be the difficulty in concurrently maintaining coating design considerations while overcoming the complexities of the coatings and their fabrication. For instance, a coating designer must consider inherent property anisotropy, in-flight decomposition of molten material (i.e., loss of stoichiometry), and occasionally the formation of amorphous materials during deposition. It is surmisable for these challenges to increase the risk of adoption of thermal spray technology in new fields. Nevertheless, industries other than those already mentioned have benefited from taking on the risk of implementing thermal spray coatings in their infrastructure. Benefits can be quantified, for example, based on reduced manufacturing cost or enhanced component performance. In this overview paper, a historical presentation of the technological development of thermal spray coatings in several of these industries is presented. Additionally, emerging industries that have not yet attained this level of thermal spray maturation will also be discussed. Finally, where applicable, the utility and benefits of multilayer functional thermal spray coating designs will be demonstrated.

热喷涂涂层是具有独特结构和性能的材料系统，促进了关键现代技术（即燃气轮机、结构集成部件等）的发展和演变。这些喷涂涂层的固有性质，例如其独特的热性能和机械性能，一直是维持工业利益的驱动力。尽管有这些好处并在多个领域取得了成功，但热喷涂技术在新应用（即清洁能源转换、半导体热喷涂材料、生物医学应用等）中的采用有时受到阻碍。一个可能的原因可能是难以同时保持涂层设计考虑因素，同时克服涂层及其制造的复杂性。例如，涂层设计者必须考虑固有特性各向异性、熔融材料的飞行中分解（即化学计量损失）以及沉积过程中偶尔形成的非晶材料。据推测，这些挑战会增加在新领域采用热喷涂技术的风险。然而，除了已经提到的行业之外，其他行业也从在其基础设施中承担热喷涂涂层的风险中受益。例如，可以根据降低的制造成本或增强的组件性能来量化效益。在这篇概述文件中，介绍了其中几个行业的热喷涂技术发展的历史。此外，还将讨论尚未达到热喷涂成熟水平的新兴行业。最后，在适用的情况下，将展示多层功能热喷涂涂层设计的实用性和优点。