Abstract: A dense, self-sintered silicon carbide/carbon-graphite composite material and a process for producing the composite material is disclosed. The composite material comprises a silicon carbide matrix, between 2 and 30 percent by weight carbon-graphite, and small amounts of sintering aids such as boron and free carbon. The silicon carbide has an average grain size between 2 and 15 .mu.m, and the carbon-graphite has an average grain size between 10 and 75 .mu.m, the average grain size of the carbon-graphite being greater than the average grain size of the silicon-carbide. The composite material has a density of at least 80 percent of theoretical density as determined by the rule of mixtures for a composite material. This density is achieved with minimal microcracking at a high graphite loading with large graphite particles. The composite material exhibits good lubricity and wear characteristics, resulting in improved tribological performance.

Abstract: The improved method of making a frangible, biodegradable clay target includes forming a plastic mixture by uniformly blending together clay, water and binder wherein the binder consists of about 1-2 percent of sodium silicate and about 0-1 percent of dextrin, by weight of the mixture, the total concentration of binder not exceeding about 2 percent, by weight of the mixture. The water is present in a concentration not in excess of 10 percent, by weight of the mixture and clay forms the remainder of the mixture. The mixture is charged into a forming press and hot pressed and dried at about 300.degree.-400.degree. F. to a finished, non-fired greenware frangible, biodegradable clay target. The improved composition is as set forth above.