One of the unique advantages of the kinetic spray process is its ability to mix constituents that would normally react with each other to form coatings. We have used this attribute to produce composite coatings with different rare earth iron alloys (REFe 2 ) and several ductile matrices. Composite coatings of Terfenol-D ((Tb 0.3 Dy 0.7 )Fe 1.9 ) and SmFe 2 were combined with ductile matrices of aluminum, copper, iron, molybdenum, tantalum, and nickel. Evidence of an induced magnetic coercivity was measured for the REFe 2 - Mo and Fe composite coatings. Coatings were produced on flat substrates and shafts. Coating morphology as well as the physical, magnetostrictive and magnetic properties of these coatings will be discussed.

This paper presents a novel approach to metallize plastic surfaces. The approach has the ability to control the electrical resistance of a metallized surface by selecting the appropriate high-melting temperature metal or alloy to be thermally sprayed. Early stages of this study concluded that twin-wire arc thermal spray of high melting temperature metals do not form continuous adhering coatings on plastic surfaces. In addition, kinetic spray deposition of metals such as copper and tin on plastic surfaces also did not provide continuous uniform metallic coatings except on a few selected plastics such as Ryton and Ultem. Rather, the kinetic sprayed particles become embedded and isolated within the plastic substrate surface when using appropriate spray conditions. By combining the kinetic and thermal spray processes we developed a novel approach to metallize plastics. The kinetic spray process is used to prepare the plastic surface with anchoring sites to later accept thermally sprayed high-melting temperature metals or alloys that provide the metallization.

An analysis of physical and mechanical properties of coatings produced by kinetic and cold spray processes is presented. Adhesion, hardnesses, porosities, critical velocities and other properties of aluminum and copper coatings from both spray methods will be analyzed and discussed, including SEM and optical micrographs. Similarities and differences between each of the coating methods and their effects on the resulting coatings are presented. A brief history and discussion of the bonding mechanisms for larger particle coatings produced by the kinetic spray method is provided.