Glassy Alloys as Potential Bearing Surfaces for Orthopaedic Implants
John A. Tesk, C E. Johnson
Glassy (amorphous) metals have some unique properties that may renderthem attractive candidates for the coating of metal-implant bearing surfaces. Metastable glasses of metal alloys, with uniform compositions and homogeous structures that are not attainable under usual quasi-euasi-equilibrium processing conditions, can often be made to produce alloys with exceptional corrosion resistance and high hardness. The absence of secondary phases argues for resistance to abrasive and asperity- initiated wear. One method of producing glassy alloys is electrodeposition. Glassy coatings from nanometers to millimeters thick can be produced. Unique compositions, such as single-phase, amorphous, cobalt-phosphorus alloys (3,9) or glass-like coatings of cobalt-chromium-carbon (6,7) alloys (those referred to by this name throughout the text have layers of amorphous chromium and cobalt that are known to have carbon dispersed throughout the chromium), can be made.