Thermal Spray Technologies, Standards and Coating Applications

Introduction

Thermal spray technologies; developed in the 1900s and continuing to advance and expand rapidly today, encompass environmentally friendly coating methods with different spray capabilities, together with coating systems and equipment. The processes are fundamentally based on melting the coating material with heat input through a spray gun and accelerating it onto the surface. Depending on the thermal and kinetic energy of the process, coating methods are named as flame spray, plasma spray, arc spray and similar designations. Spraying operations can be performed in atmospheric (APS) or controlled atmosphere (VPS, LPPS), with coating materials in solid, solid particle or suspension (SSPS) form. In addition to having a wide range of materials, it has the potential to create coating layers on any type of substrate. Coating operations can be performed on-site or in open air within a booth. It is highly suitable for robotic applications and automation. Depending on spray gun characteristics and pipe diameter, coatings can be applied to hollow pipes. In industry, applications serve not only to protect many metallic material surfaces from aggressive atmospheric conditions, to impart surface resistance, and to restore and repair surfaces, but also enable modification of the surface's physical, chemical and electrical properties. In addition to coating materials produced in specific sizes and different forms through powder metallurgical methods, wear-resistant, corrosion-resistant and high-temperature-resistant coatings can be produced using metallic, ceramic or polymer-based coating materials in the form of wires or rods of different diameters. Coatings have different microstructural properties depending on spraying conditions, method and coating material characteristics, and generally have a heterogeneous structure. Today's most common application areas are: transportation, energy, mining, metal production, biomedical and electronics sectors.

Thermal Spray Market

As of 2015, the global market size of thermal spray coating technologies, including coating units, coating materials and coating applications combined, reached USD 7.58 billion. With a growth rate of 7.79%, it is expected to reach USD 11.89 billion in 2021. Among the most important driving forces in market development are increased thermal resistance of gas turbines as a result of rising energy production demand, protection of aircraft engine components and extension of turbine component life in air transport, reduction of friction in automotive parts, prevention of wear, and tribological improvements taking prominent positions. Another important factor is the growing need for environmentally friendly coating technologies, which is accelerating the increase in the usage rate of thermal spray coatings as an alternative to traditional coating methods. In particular, compared to electrolytic and chemical coatings (such as hard chromium), the thermal spray method (HVOF) provides wear-resistant, corrosion-resistant, non-porous, high-strength coatings. Similarly, as an alternative to galvanizing coating applications, zinc, aluminum, zinc-aluminum and zinc-magnesium-based coatings can be produced through thermal spray technique with high corrosion resistance.

Thermal Spray Advantages

In industrial applications, alongside expectations of reducing per-unit production costs, increasing part quality and reliability, and increasing process efficiency and profitability, there is growing need for applications requiring less maintenance and repair as a result of faster and increasingly higher-capacity operating conditions. Thermal spray technology provides versatile solutions at this point. In this context, development of new types of coating materials, advanced spray gun designs, and robotic coating applications make it possible to produce repeatable coatings of high quality and performance. Thermal spray technology has a versatile and rapidly evolving coating family. In this context, every day new coating materials are being developed in compositions and forms suited to the purpose, and in parallel, significant technological improvements are being observed in coating methods and systems, and in coating units. Beyond this, it has numerous application areas ranging from mega-scale steel structures, to ships, nuclear reactors, to large steel rolls.

Thermal Spray Themed Research, Conferences and Trade Fair Organizations

In leading developed countries worldwide, universities and research institutions conduct scientific and technological research on thermal spray technologies, carrying out comprehensive projects and important scientific activities that enhance surface properties. The International Thermal Spray Association (ITSA) was established in 1948, ASM Thermal Spray Society in 1994, and the European Thermal Spray Association (ETSA) in 2011. On the European continent, particularly Germany, France, Spain, Italy, Finland and Sweden, and on the American continent the United States, Brazil and Canada, and in the Far East India, Japan and China along with Russia are among the countries making important contributions to the development of thermal spray technologies. In industrial applications, thermal spray technologies have now become part of many companies' standards, leading to increased quality expectations and creating serious competition. Many countries are producing innovative surface solutions and continuing the search for new application areas and markets. Each year, an international thermal spray conference (ITSC) and trade fair are held in one of the American, Asian and European continents, and participation rates have shown an increase every passing year since the 1990s. ITSC-2015 was held in California, ITSC-2016 in China, and ITSC-2017 will be held in Düsseldorf, Germany. Dr. Ekrem Altuncu / ETSA / TESLAB - Sakarya University, Faculty of Technology, Metallurgy and Materials Engineering Department

Important web pages about thermal spray

Important web pages about thermal spray

1. http://www.asminternational.org/web/tss

2. http://etsa-thermal-spray.org/

3. http://www.thermalspray.org/

4. http://www.tssea.co.uk

5. http://www.gordonengland.co.uk/

6. http://www.gts-ev.de

7. http://www.chinathermalspray.org/

8. http://www.jtss.or.jp/

9. http://www.asiantss.com/

on of thermal spraying equipment - Part 1: General requirements. 9. EN 1395-2 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 2: Flame spraying including HVOF.

10. EN 1395-3 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 3: Arc spraying.

11. EN 1395-4 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 4: Plasma spraying.

12. EN 1395-5 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 5: Plasma spraying in chambers.

13. EN 1395-6 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 6: Manipulator systems

14. EN 1395-7 Thermal spraying - Acceptance inspection of thermal spraying equipment - Part 7: Powder feed systems.

15. EN ISO 14922-1 Thermal spraying - Quality requirements of thermally sprayed structures - Part 1: Guidance for selection and use.

16. EN ISO 14922-2 Thermal spraying - Quality requirements of thermally sprayed structures - Part 2: Comprehensive quality requirements.

17. EN ISO 14922-3 Thermal spraying - Quality requirements of thermally sprayed structures - Part 3: Standard quality requirements.

18. EN ISO 14922-4 Thermal spraying - Quality requirements of thermally sprayed structures - Part 4: Elementary quality requirements.

19. EN 13214 Thermal spraying - Thermal spray coordination - Tasks and responsibilities.

20. EN 15311 Thermal spraying – Components with thermally sprayed coatings – Technical supply conditions.

21. EN 15339-1 Thermal spraying - Safety requirements for thermal spraying equipment - Part 1: General requirements.

22. EN 15339-2 Thermal spraying - Safety requirements for thermal spraying equipment - Part 2: Gas control units.

23. EN 15339-3 Thermal spraying — Safety requirements for thermal spraying equipment Part 3: Torches for thermal spraying and their connection and supply units.

24. EN 15339-4 Thermal spraying — Safety requirements for thermal spraying equipment Part 4: Gas and liquid fuel supply.

25. EN 15339-5 Thermal spraying — Safety requirements for thermal spraying equipment Part 5: Powder and wire feed units.

26. EN 15339-6 Thermal spraying - Safety requirements for thermal spraying equipment - Part 6: Spray booth, Handling system, Dust collection, Exhaust system, Filter.

27. EN 15648 Thermal spraying - Component related procedure qualification

28. EN 582 Thermal spraying. Determination of tensile adhesive strength

29. EN 15340 Thermal spraying - Determination of shear load resistance of thermally sprayed coatings

30. EN ISO 14920 Thermal spraying - Spraying and fusing of self-fluxing alloys.