Previous efforts to spray-form metal structures using conventional plasma spray have usually resulted in shapes which had very limited ductility because of excessive porosity and oxidation. It has recently been shown that the spray of metals in a near-vacuum environment virtually eliminates these limitations. The vacuum plasma spray-form process can thus be used to manufacture certain metal shapes which are difficult or impossible to form by conventional processes such as casting or forging. This is particularly true for refractory metals because their high melting point makes casting and forging difficult. The vacuum plasma spray-form process has many other advantages for the manufacture of shaped-charge liners. For instance, the process is a relatively cool process, in that the mandrel being sprayed can kept below 250. Shapes can thus be formed to a high degree of dimensional accuracy, L*A which eliminates or reduces theAmount of post-deposition finishing required. The process is also amenable to high-production output, and parts formed by the process are characterized by fine grain size, freedom from segregation, and microstructural uniformity. This proposal outlines a plan to compare the metallurgical and mechanical properties of several vacuum plasma spray-formed refractory metals to those of the same refractory metals manufactured using conventional techniques, and to manufacture twelve 81-mm shaped charge liners for government analysis. The demonstrated capability of the vacuum plasma spray process to form refractory metal shapes will have important commercial implications. The process can also be used to form refractory metal shapes for the aerospace, chemical, and nuclear industries, among others.
