Adhesion (bond-strength) testing of thermal spray coatings is performed in accordance with ASTM C 633-01 “Standard Test Method for Adhesion or Cohesion Strength of Thermal Spray Coatings.” The test measures the force required to separate a thermal spray coating from its substrate. Depending on its bond strength, the coating can fail at any of several locations including the coating-substrate interface, within the coating, and at the interface between the coating and the bonding agent. For some coatings (such as HVOF WCCo), the adhesive strength of the coating is typically greater than the strength of the bonding agent. The two most common bonding agents are FM-1000 and EC-2214.  FM-1000 comes in the form of a wafer, while EC-2214 is a liquid. Both bonding agents are applied between the coating and a mating metallic slug. After curing, the coating is subjected to increasing tensile load until failure. While FM-1000 can be used for any coating, EC-2214 should only be used for dense coatings. Because it is a liquid, it is possible for EC-2214 to penetrate a porous coating and bond to the substrate. As a result, artificially high bond strength values could be measured.

Source: Doug Puerta, KHA Metallurgical, Portland, Oregon

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)