WORKSHOP SUMMARY

The NIST Metallurgy Division has initiated a research program to investigate coatings produced by thermal spray (TS) techniques. The focus of this research is the development of measurement tools that will aid in the understanding and/or control of the plasma spray process. This process uses plasma jets (generated by either DC or AC arcs) to melt or soften coating feed-stocks and then propel this material onto various substrates. The geometry and operating parameters of the plasma jet hardware, or "gun", depend on the intended function of the resulting TS coated part. Currently TS coatings are produced by skilled technicians, however, it is now being adapted for automatic control using robotics. Intelligent Processing incorporating expert systems will probably be employed in most advanced systems. This move to robotics is not only to reduce costs, but to improve the reliability of spray coatings and thus enable the use of coatings in high volume applications such as automotive components and property critical devices such as the proposed high-efficiency gas turbines.

Recently a number of advances have been made in new measurement systems, sensors, and modeling techniques that can lead to improved design and control of thermal spray processes. The objectives of this workshop were to present descriptions of some of these advances and their industrial applications, demonstrate some of the systems currently available or under development at NIST, and provide a forum to allow discussion of the current industrial measurement needs for thermal spray coatings.

NISTIR 6460 Related Links:

• NISTIR 6460: Thermal Spray Coatings Workshop in Adobe Acrobat PDF (7.2 MB)
• NIST 18-hole gas atomizer movie in QuickTime format (2.2 MB) or AVI format (3.5 MB)
• Superheated Ni splat in QuickTime format (900 kB) or AVI format (2.3 MB)
• Side view of undercooled splat in QuickTime format (670 kB) or AVI format (1.7 MB)
• LENS side view in QuickTime format (360 kB) or AVI format (645 kB)
• Schlieren strobe of twin wire arc spray in QuickTime format (1.2 MB) or AVI format (4.6 MB)