This article provides a high-level overview of thermal spray technologies and their applications and benefits. It is intended to educate members of government, industry, and academia to the benefits of thermal spray technology. The article describes the value of thermal spray technology with examples of application success stories. A few applications critical to thermal spray and market growth are briefly discussed. The article also summarizes the key research areas in thermal spray technology.

This article provides a brief description of commercially important thermal spray processes and gives examples of applications and application requirements. The processes covered are flame, wire arc, plasma, high-velocity oxyfuel processes, detonation gun, and cold spray methods. Examples are provided of the applications in aerospace, automotive, and medical device industries as well as the use of thermal spray as an additive manufacturing technique.

This article summarizes the results of work completed by the ASM Thermal Spray Society Advisory Committee to identify key research challenges and opportunities in the thermal spray field. It describes and prioritizes research priorities related to emerging process methods, thermal spray markets and applications, and process robustness, reliability, and economics.

This article presents best practices for the metallographic preparation of specimens produced via thermal spray coating methods. It outlines typical metallographic preparation process flow, highlighting important considerations for obtaining a clear and representative specimen suitable for characterization via examination techniques, such as optical or electron microscopy. The process flow includes preliminary resin infiltration, sectioning, mounting, grinding, and polishing. To aid in the identification and resolution of common issues during subsequent specimen analysis, the article presents common issues, along with causes and mitigation strategies. It describes the processes involved in the interpretation of the thermal spray coating microstructure.

Thermal barrier coatings (TBCs) are applied using thermal spray coating (TSC) processes to components that are internally cooled and operated in a heated environment. The TSC microstructures are prone to interactions with common metallographic procedures that may result in artifacts and misinterpretation of the TSC microstructure. This article aims to aid in identifying metallographic TSC artifacts, specifically in the air plasma spray zirconia-based TBC, including both of its common constituents, the bond coating and the top coating. Artifacts that result from specific sectioning and mounting practices, as well as from different polishing times, are presented. Additionally, the article discusses the factors in optical microscopy and scanning electron microscopy that affect microstructure interpretation.

Abradable coatings (such as Ni-4Cr-4Al/bentonite) are used throughout jet engines, primarily as sacrificial coatings into which moving components wear. This article presents the Accepted Practice for sample preparation of abradable coatings for metallographic analysis, based on round robin testing by several laboratories.

Molybdenum thermal spray coatings are used in aerospace and other industries for wear resistance applications. Metallographic sample preparation of molybdenum coatings presents unique challenges. The purpose of the investigation described in this article is to determine Accepted Practices for sample preparation to better understand the process related microstructures of thermal spray molybdenum powders. The committee followed a round robin approach to assess metallographic sample preparation by a variety of laboratories. The article summarizes the results of the committee’s work.

This article, prepared under the auspices of the ASM Thermal Spray Society Committees on Accepted Practices, describes a procedure for evaluating residual stresses in thermal spray coatings, which is an extension of the well-known layer removal method to include the Young’s modulus and Poisson’s ratio properties of the thermal spray coating material and the substrate. It presents questions and answers that were selected to introduce residual stresses in thermal spray coatings. The article describes equipment and the laboratory procedure for the modified layer removal method and provides the description of the residual stress specimen. It also describes the procedures for applying or installing bonded resistance strain gages, the dimensions of the test specimen, the procedure for removing layers, and the method for interpreting the data to evaluate residual stresses. The spreadsheet program, “ MLRM for Residual Stresses ,” is available as a supplement to this document.

This article addresses critical aspects in bond testing of thermal spray coatings and provides step-by-step guidance for obtaining representative and reproducible test results based on ASTM C633 and other applicable industry standards. It clarifies details of ASTM C633 requirements and provides examples of the best practice confirmed by hundreds of tests performed worldwide, adopted by numerous industrial standards, and requested to comply with international technical standardization and certification organizations such ISO, AS, SAE, and Nadcap.

This chapter discusses the importance of failure analysis and the role it plays in a society driven by technological advancement. It explains why failure rates are highest in the early and later stages of the life of any product and shows the extent to which failure rates increase when products are subjected to an aggressive operating environment.

This chapter discusses some of the ways that the lessons learned from failures have benefitted society, leading to improved product designs, better materials, safer industrial processes, and more robust codes and standards. It also provides several examples of how the technology and procedures associated with aviation security have been upgraded in the wake of air disasters.

In 1924, the American Society for Testing and Materials (ASTM) organized the symposium "Corrosion and Heat Resisting Alloys, and Electrical Resistance Alloys." It was the beginning of a major role that ASTM played in the history of stainless steel. This chapter provides information on the papers presented at the 1924 symposium. It also describes the role of ASTM in stainless steel standardization after the 1924 symposium.

The design stresses for most pressure-containing structural application, which are based upon minimum mechanical properties designated in the specifications published by the American Society for Testing and Materials (ASTM). This chapter reviews metallurgical characteristics and their influence on the properties and performance of structural carbon and low alloy steels and contains a summary of the relevant features of the ASTM product specifications.