The HVOF (high velocity oxy-fuel) process efficiently uses high kinetic energy and controlled thermal output to produce dense, low-porosity coatings that exhibit high bond strengths (some of which exceed 83 MPa, or 12,000 psi), low oxides, and extremely fine as-sprayed finishes. The coatings have low residual internal stresses, and therefore, can be sprayed to a thickness not normally associated with dense, thermal spray coatings. This process uses an oxygen-fuel mixture. Depending on user requirements, propylene, propane, hydrogen, or natural gas can be used as the fuel in gas-fueled spray systems and kerosene as the fuel in liquid-fueled systems. The coating material in powder form is fed axially through the gun, generally using nitrogen as a carrier gas. The fuel is thoroughly mixed with oxygen within the gun and the mixture is then ejected from a nozzle and ignited outside the gun. The ignited gases surround and uniformly heat the powder spray material as it exits the gun and is propelled to the workpiece surface. As a result of the high kinetic energy transferred to the particles through the HVOF process, the coating material generally does not need to be fully melted. Instead, the powder particles are in a molten state and flatten plastically as they impact the workpiece surface. The resulting coatings have very predictable chemistries that are homogeneous and have a fine granular structure.

TSS Regional Events

Aerospace Coatings Symposium
October 15-16 2008
Sheraton Bradley Hotel, Bradley (Connecticut) International Airport
Learn about some of the latest developments in thermal spray and other surface engineering technologies designed specifically for use in the aerospace industry.

Pre-Event Seminar
Materials and Processes for High Temperature Gas Turbine Components
October 13-14, 2008
Sheraton Bradley Airport
Instructor: Dr. Donald Boone, President, BWD Turbines Ltd., Walnut Creek, Calif.
Seminar focuses on thermal spray and other surface modification processes critical to the aerospace industry.

Symposium on Improving Reliability and Consistency in Thermal Spray
December 2-3, 2008
Hyatt Regency Montreal, Quebec, Canada
Presentations by invited speakers covering reliability and consistency of thermal spray processes and coatings, and poster session.

Sponsorships Available for Both Events
To learn more about tabletop exhibiting and sponsorship opportunities, or to discuss customizing a program to meet your specific needs, contact Kelly Thomas, Exposition Sales Manager (440-338-1733)