Air Products has introduced a new thermal spray cooling technology to the North American market that uses cryogenic nitrogen vapour to maintain parts temperature, during thermal spray coating applications.
The technology can enable the user to apply coatings faster and at a lower cost than traditional cooling methods. Exposing a part to too much heat can negatively impact coating adhesion, substrate and coating hardness, fatigue life, corrosion resistance and dimensional tolerances.
Dr Rana Ghosh, project manager for cryogenic cooling applications at Air Products, commented, “Air Products recognized that thermal spray applicators needed a better solution to maintaining part temperature.”
“In response, we developed a thermal spray cooling technology that can maintain a part's temperature within a much tighter range during the spray operation versus traditional cooling methods, by varying the cooling intensity to match the heat generated in the spraying process. Use of our technology can improve part quality, lower costs by reducing powder and process gas waste and enable the use of inexpensive flexible masking, and allow better utilization of the thermal spray equipment and booth,” added Ghosh.
One method used by thermal spray applicators to keep part temperatures within a closely set range is forced air cooling combined with inter-pass breaks. This traditional practice has its drawbacks though, as it increases downtime and reduces productivity, as well as wasting powder and process gases.
During spray application using Air Products’ technology however, the cryogenic vapour jet follows the thermal spray plume to maintain the part's temperature within the specified range. The part is continuously monitored by a thermal imaging camera and/or infrared sensors that provide temperature feedback to the computer-controlled cooling nozzles, which allows the cooling system to automatically maintain the substrate temperature set by the operator.
Compatible with existing thermal spray systems, Air Products' technology offers a variety of system designs for application-specific use and can be used in the aerospace, automotive, and heavy industries.