Ultrafine-grained titanium for medical implants
AssigneeThe Regents of the University of California
InventorsYuntian T. Zhu, Terry C. Lowe, Ruslan Z. Valiev, Vladimir V. Stolyarov, Vladimir V. Latysh, Georgy J. Raab
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Abstract
We disclose ultrafine-grained titanium. A coarse-grained titanium billet is subjected to multiple extrusions through a preheated equal channel angular extrusion (ECAE) die, with billet rotation between subsequent extrusions. The resulting billet is cold processed by cold rolling and/or cold extrusion, with optional annealing. The resulting ultrafine-grained titanium has greatly improved mechanical properties and is used to make medical implants.
Claims50
A medical implant comprising ultrafine-grained titanium made by the process comprising the steps of:
- (a) placing a coarse-grained titanium billet into a lubricated first channel of a preheated equal channel angular extrusion die and extruding the billet through a second channel of the die that intersects with the first channel;
- (b) rotating the extruded billet a chosen amount around its longitudinal axis and extruding the rotated billet again;
- (c) repeating step (b) a chosen number of times;
- (d) subjecting the product of step (c) to cold processing;
- and
- (e) fabricating the medical implant from the product of step (d).
A medical implant, comprising ultrafine-grained titanium having an ultimate strength of about 860-1100 MPa and yield strength of about 795-1050 MPa.
A method of producing ultrafine-grained titanium, comprising the steps of:
- (a) placing a coarse-grained titanium billet into a lubricated first channel of a preheated equal channel angular extrusion die and extruding it through a second channel of the die that intersects with the first channel;
- (b) rotating the extruded billet a chosen amount around its longitudinal axis and extruding the billet again;
- (c) repeating step (b) a chosen number of times;
- and
- (d) subjecting the product billet of step (c) to cold processing to produce said ultrafine-grained titanium.
Ultrafine-grained titanium having an ultimate strength of about 860-1100 MPa and yield strength of about 795-1050 MPa.
A device comprising ultrafine-grained titanium made by the process comprising the steps of:
- (a) placing a coarse-grained titanium billet into a lubricated first channel of a preheated equal channel angular extrusion die and extruding the billet through a second channel of the die that intersects with the first channel;
- (b) rotating the extruded billet a chosen amount around its longitudinal axis and extruding the rotated billet again;
- (c) repeating step (b) a chosen number of times;
- (d) subjecting the product of step (c) to cold processing;
- and
- (e) fabricating the device from the product of step (d).
A device comprising ultrafine-grained titanium, the titanium having an ultimate strength of about 860-1100 MPa and a yield strength of about 795-1050 MPa.
Dependencies are inferred from the claim text.