Magnetic thin films formed in a glow discharge. Final report

Since this project is a continuation of a cooperative effort between UMR and General Motor Research Laboratories (GMR), it seemed fitting to provide some background information which was instrumental in the evolution of this program. A family of filled epoxies that can be cast-to-size into sheet metal stamping dies has been developed by GMR. Advantages of this material over commercial plastic tooling materials are a fast curing rate, high strength, and negligible volume shrinkage after curing. Superior Tooling And Molding Plastic (STAMP) tooling dies are considerably cheaper and faster to make than steel tooling dies; therefore, they are currently used for prototype applications throughout General Motors. With improvement of wear resistance, STAMP dies can be used for limited production applications involving 10,000 or 20,000 parts. GMR proposed to provide a thin (< 25 {micro}m) wear surface for the cast-to-size STAMP die to extend its wear performance. The objective of the University of Missouri-Rolla (UMR) research effort is to technically evaluate methodologies to coat STAMP material to appreciably improve wear resistance. This does not necessarily mean that various types of coatings will be developed and evaluated. Rather, the primary responsibility is to characterize the nature of the STAMP material and design engineered films which will lead to an optimized system. An example of this was the finding that a thin polymer layer existed on the surface of an as-cast STAMP die necessitating removal if satisfactory adherence and toughness were to be attained. The next important finding involved the influence of particle size on wear. The theme of the research approach was maintained throughout the course of the project, with improvements being made as the causes of failure were determined and appropriate corrections or improvements were made