Glass-ceramic-metal composites for making graded seals in prosthetic devices

The possibility of using glass-ceramic-metal composites as graded seals between dense cores of prostheses and a porous glass-ceramic coating, which would promote a direct bond with the bone has been investigated, particularly with respect to thermal and elastic properties. Before binding them to a core, bulk composite materials have been prepared in order to study their properties.These materials have been obtained from powdered mixtures of a calcium alumino-phosphate glass (CAP) with increasing volume fractions (3.5–50%) of various metals or alloys: titanium, 316 L stainless steel, cobalt-chromium 788 alloy. They have been synthesized by hot pressing immediately followed by a heat treatment to obtain ceramicization of the glass matrix.Elastic and thermal properties have been determined. The values of elastic moduli and average linear thermal expansion coefficients lie within those of glass-ceramic CAP and those of the corresponding metal. Mechanical properties have been also measured. The material can withstand about four times the body weight when materials are bound to a more rigid metal or alloy.