Volume 9, Issue 2 (February 2012)
Adhesion of Thermally Sprayed Metallic Coating
An adhesion testing device was built, based on the ASTM C 633-79 standard, to study the deposition of metallic coatings produced by the HVOF (high velocity oxygen fuel) thermal spray process with the materials 1342 VM, 1350 VM, and 8812, and by the arc spray (AS) process with the materials STELLIT 6 PM SD 38 EF, 97 MXC, and 140 MXC. This type of test is widely used as a tool to determine the influence of the conditions of the thermal spray technique, substrate surface and abrasive blasting on the strength, and adhesion of the sprayed layer on the substrate. The sprayed coatings were characterized based on their hardness, metallographic characteristics, and roughness measurements. They also underwent adhesion tests, and the fracture surfaces of each material were analyzed, revealing mixed results, i.e., different types of fractures involving cohesive fracture, adhesive failure, and adhesive fracture, according to the type of coating produced.