IMPROVED WEAR RESISTANCE OF IMPLANT TITANIUM ALLOY BY ION IMPLANTATION

TITANIUM ALLOYS OFFER SUPERIOR CORROSION RESISTANCE, MECHANICAL STRENGTH, LOWER ELASTIC MODULUS AND SPECIFIC WEIGHT, AND BIOCOMPATIBILITY. THE LOWER WEAR/ABRASION TOLERANCE OF TITANIUM, HOWEVER, HAS HAMPERED ITS FULL SCALE APPLICATION IN ORTHOPAEDIC SURGERY. FOR LONG TERM RELIABILITY OF THE TITANIUM IMPLANT, THE WEAR CHARACTERISTIC OF THE ALLOY MUST BE MODIFIED. ADVANCES IN THE TECHNOLOGY AND METALLURGY OF ION IMPLANTATION HAVE OPENED DOORS TO POTENTIAL APPLICATION IN SURFACE MODIFICATION OF MATERIALS. CURRENT LITERATURE DEMONSTRATES THAT TRIBOLOGICAL BEHAVIOR OF MATERIALS CAN BE IMPROVED, IN CERTAIN CASES DRAMATICALLY, BY USING THIS ION IMPLANTATION TECHNIQUE. IN THIS PROPOSAL, WE WILL ADDRESS THE APPLICATION OF THIS TECHNIQUE TO THE IMPROVEMENT OF WEAR RESISTANCE OF TITANIUM ALLOY. IT IS ANTICIPATED THAT A SUCCESSFUL PROGRAM WILL (1) ALLOW THE USE OF THE ALLOY IN HIGHER WEAR JOINTS LIKE KNEE, (2) PROVIDE A BETTER PROSTHESIS/BONE INTERFACE, AND (3) LEAD TO LOWER CORROSION RATES AND LESS METAL ION DISSOLUTION THAN COBALT ALLOY. IT CAN THEREFORE BE EXPECTED THAT IMPROVED WEAR RESISTANCE COUPLED WITH EXCELLENT MATERIAL PROPERTIES OF THE TITANIUM, WILL LENGTHEN THE LIFETIME, IMPROVE RELIABILITY OF THE IMPLANT DEVICES AND MAKE THE BENEFITS OF ORTHOPAEDIC SURGERY AVAILABLE TO YOUNGER PATIENTS WHO SUFFER DAMAGED OR DISEASED JOINTS. IN THIS FEASIBILITY STUDY, EXPERIMENTS WILL BE DESIGNED AND PERFORMED TO ESTABLISH THE TECHNICAL MERITS OF THE PROCESSING TECHNOLOGY. PHYSICAL METALLURGICAL PRINCIPLES AND PREVIOUS EXPERIENCES WITH OTHER ALLOY SYSTEMS WILL BE OUR GUIDE IN THIS EXPLORATORY RESEARCH.