It has been just over 100 years since Swiss Inventor Max Ulrich Schoop filed his first patents for a thermal spray device and process. The first thermal spray processes, electric arc wire spray and combustion wire spray, really created the industry that was then known as “metallizing.” The process, at that time, consisted basically of a metallic coating feedstock melted using arc or combustion process as a heat source, then atomizing and propelling the melted feedstock to a substrate material to form a coating. Of course, like most industrial processes, metallizing continued to evolve. The eventual developments that allowed the use of feedstock materials such as ceramics and carbides made the term metallizing obsolete; hence, the term “thermal spray” is now used to refer to this family of processes. And a family of processes it is. While the common method of the entire family is to use some sort of heat source to melt or soften the material and propel the atomized feedstock to form a coating, differences in the types of feedstock materials (powders, wires, rods) and the heat sources used form the different classes and subclasses of thermal spray processes that continue to evolve and grow today. In this regard, thermal spray as a growing family of processes parallels welding. What also parallels welding is the level of technology and process automation. As what we can do with computerized systems, process controls, and feedback systems evolves — sometimes at quite a rapid rate — application equipment that we might have classified as “automated” several decades ago might now be reclassified as “semiautomated.” In addition, manufacturing of both thermal spray application equipment and the feedstock materials grows ever more rigorous, driven by both customer demand for better reliability, repeatability, cost control, and advancing technology. What is most exciting is the breadth of industries that use thermal spray. Even though the global market size of thermal spray is a fraction of the size of the welding industry, there are many applications where thermal spray is critical to the functioning of a part or system. The permutation of the variety of applications versus the types of surface challenges that thermal spray can solve seems almost limitless. Our industry is always facing new application challenges and coming up with new materials and application techniques to solve them. So while the goal of thermal spray is always to apply a functional coating, the choice of thermal spray process, feedstock material, and application technique used to create that surface is dictated by the functional purpose of the coating, the service environment, and, of course, financial factors. Some of these surfaces have to withstand the harshest of complex corrosion and wear conditions. Others produce very specialized surfaces for insulation, conduction, frictional coefficients, or decorative enhancement. Still, others are used to control or restore dimensions. It is the mission of the AWS C2 Committee on Thermal Spraying to lead our evolving industry with new advances and thermal spray techniques, as well as publishing documents with basic information that guide companies just getting into thermal spray. Unlike welding, which has many different AWS committees for its various processes, equipment, and materials, C2 handles all matters related to thermal spray. Fortunately, we have a membership and advisor roster comprised of very energetic, talented, and knowledgeable individuals who cover many different facets of our industry. While our ranks have grown over recent years, thanks in large part to the efforts of past Chair David Lee, we always welcome additional members. If currently interested in volunteering, contact Secretary Jennifer Rosario at jrosario@aws.org. As a result of all the many reasons previously mentioned, the committee has found that most of our specifications have required extensive revisions, and in a few cases, some adjustment of the publication focus. Of course, we have been hard at work doing just that. Nonetheless, to further promote and guide our evolving industry, the committee is also considering new thermal spray guidelines and specifications. The C2 committee is dedicated to meeting the needs of the thermal spray industry with relevant publications that reliably provide guidance and direction. We certainly look forward to our industry’s continued evolution. If your company uses thermal spray or is thinking about using thermal spray, we invite you to join us as our guest. Better yet, consider joining our team as a member. EDITORIAL Thermal Spray Gets Used by a Breadth of Industries while the AWS C2 Committee Continues to Lead with New Advances Karen Sender Chair, AWS C2 Committee on Thermal Spraying “It is the mission of the AWS C2 Committee on Thermal Spraying to lead our evolving industry with new advances and thermal spray techniques, as well as publishing documents with basic information that guide companies just getting into thermal spray.” 6 WELDING JOURNAL / AUGUST 2015 WJ
Welding Journal | August 2015
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