# US 6,258,182 B1 · Pseudoelastic β titanium alloy and uses therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,258,182 B1 - Document ID: US6258182B1 - Status: Granted - Kind: B1 - Application number: 09/263,658 - Filed: 1999-03-05 - Granted: 2001-07-10 - Earliest claimed: 1998-03-05 - Assignees: Memry Corporation - Inventors: L. McDonald Schetky; Ming H. Wu; Chi-Yuan Loi; Charles J. Burstone - Web page: https://patentgrep.com/patent/US6258182B1 ## CPC - C22F 1/006: {Resulting in heat recoverable alloys with a memory effect} - A61L 31/022: {Metals or alloys} - C22C 14/00: Alloys based on titanium - A61B 17/0642: {for bones, e.g. for osteosynthesis or connecting tendon to bone} - A61B 17/866: {Material or manufacture} - A61B 2017/00867: {shape memory effect} - A61C 5/42: Files for root canals; Handgrips or guiding means therefor - A61C 7/20: Arch wires (A61C7/28 takes precedence) - A61C 8/0012: {characterised by the material or composition, e.g. ceramics, surface layer, metal alloy (use of specific materials A61K6/00)} - A61F 2/82: Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents (stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07) - A61L 2400/16: Materials with shape-memory or superelastic properties - C22F: CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass, C23F17/00) - A61L: METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES (preservation of bodies or disinfecting characterised by the agents employed A01N; preserving, e.g. sterilising, food or foodstuffs A23; preparations for medical, dental or toiletry purposes A61K) - C22C: ALLOYS (treatment of alloys C21D, C22F) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract The disclosed β titanium alloys contain alloying elements of molybdenum between 10.0 and 12.0 weight percent, aluminum between 2.8 and 4.0 weight percent, chromium and vanadium between 0.0 and 2.0 weight percent, and niobium between 0.0 and 4.0 weight percent. Orthodontic arch wires and appliances of nickel-free β titanium alloys having pseudo-elastic properties associated with stress-induced martensitic transformation. These arch wires and appliances were found to possess a high strain recovery up to 3.5% strain of deformation, a lower stiffness yielding relatively constant force for tooth movement and improved formability over that of pseudo-elastic nitinol. Eyeglasses having parts made of such materials can be welded. Stents made of this material avoid problems which a certain percentage of the population have when nickel is included within alloys used in the human body. Other medical devices which are used in the body also have this benefit. One of the main benefits of this alloy, is that a certain percentage of the population is sensitive to the presence of Ni and for this reason there has been interest in obtaining a non-NI alloy exhibiting the above super elastic and chemical properties. ## Claims ### Claim 1 A substantially nickel-free β titanium alloy comprising: (a) between 10.0 and 12.0 wt. % molybdenum; (b) between 2.8 and 4.0 wt. % aluminum; (c) chromium and vanadium each between 0.0 and 2.0 wt. %; and (d) between 0.0 and 4.0 wt. % niobium; and (e) the balance titanium, there being at least one element selected from the group consisting of chromium, vandadium, and niobium. ### Claim 2 (depends on 1) An alloy as defined in claim 1 characterized by exhibiting pseudo-elasticity in the range of −25°C. to 50° C. ### Claim 3 (depends on 2) An alloy as defined in claim 2, which exhibits shape memory effect when deformed at room temperature and subsequently subjected to heating. ### Claim 4 (depends on 2) An alloy as defined in claim 2 which exhibits pseudo-elasticity between 25 and −25° C. ### Claim 5 (depends on 4) An alloy as defined in claim 4, which has a strain recovery of approximately 2.7% when tensile loaded to 4% strain at room temperature in the as-solution treated condition. ### Claim 6 (depends on 2) An alloy as defined in claim 2 formed into an orthodontic arch wire, springs, implants or endodontic files. ### Claim 7 (depends on 2) An alloy as defined in claim 2 formed into eyeglasses. ### Claim 8 (depends on 2) An alloy as defined in claim 2 formed into a medical device for use within a living body. ### Claim 9 (depends on 8) An alloy as defined in claim 8 wherein said medical device is chosen from the following group: (1) a stent; (2) a catheter introducer; (3) oral pins and/or plates used in maxillofacial reconstructive procedures; (4) oviduct clamp; and (5) bone staples. ### Claim 10 (depends on 1) An alloy as defined in claim 1 capable of being cold worked up to 20% without significantly reducing the pseudo-elastic performance, whereby it is capable of being cold formed into various shapes at ambient temperature while retaining the high spring-back characteristics of the pseudo-elastic phenomenon. ### Claim 11 (depends on 1) An alloy as defined in claim 1 which exhibits pseudo-elasticity at ambient and/or body temperature. ### Claim 12 (depends on 11) An alloy as defined in claim 11, which has a strain recovery up to approximately 3.5% when tensile loaded to 4% strain at room temperature in the as-solution treated condition. ### Claim 13 (depends on 11) An alloy as defined in claim 11 characterized by exhibiting almost complete elastic behavior when deformed up to 4%, thereby permitting the designing of medical instruments and devices which are resistant to permanent deformation. ### Claim 14 (depends on 1) An alloy as defined in claim 1, comprising, molybdenum of 10.2 wt. %, aluminum of 2.8 wt. %, vanadium of 1.8 wt. %, niobium of 3.7 wt. % and the balance of titanium and exhibiting pseudo-elasticity in the range of 25 and −25° C. ### Claim 15 (depends on 1) An alloy as defined in claim 1, comprising molybdenum of 11.1 wt. %, aluminum of 2.95 wt. %, vanadium of 1.9 wt. %, niobium of 4.0 wt. % and the balance of titanium and exhibiting pseudo-elasticity in the range of 50 and −25° C. ### Claim 16 (depends on 1) An alloy as defined in claim 1, which has been subjected to a heat treatment consisting of solution heating between 780 and 880 degrees C. ### Claim 17 (depends on 1) An alloy as defined in claim 1 formed into an eyeglass part. ### Claim 18 A method for making a substantially nickel-free β titanium alloy, comprising the steps of alloying together: (a) between 10.0 and 12.0 wt. % molybdenum; (b) between 2.8 and 4.0 wt. % aluminum; (c) chromium and vanadium each between 0.0 and 2.0 wt. %; and (d) between 0.0 and 4.0 wt. % niobium; and (e) the balance titanium, there being at least one element selected from the group consisting of chromium, vanadium, and niobium. ### Claim 19 (depends on 18) A method as defined in claim 18, further comprising cold working the alloy up to 20% without significantly reducing the pseudo-elastic performance, whereby the alloy is capable of being cold formed into various shapes at ambient temperature while retaining the high spring-back characteristics of the pseudo-elastic phenomenon. ### Claim 20 (depends on 18) A method as defined in claim 18, further comprising the step of forming the alloy into an orthodontic arch wire. ### Claim 21 (depends on 18) A method as defined in claim 18, further comprising the step of forming the alloy into at least one part for eyeglasses. ### Claim 22 (depends on 18) A method as defined in claim 18, further comprising the step of forming the alloy into a medical device for use within a living body. ### Claim 23 (depends on 22) A method as defined in claim 22, wherein said medical device is chosen from the following group: (1) a stent; (2) a catheter introducer; (3) oral pins and/or plates used in maxillofacial reconstructive procedures; (4) oviduct clamp; and (5) bone staples. ### Claim 24 (depends on 18) A method as defined in claim 18 further comprising subjecting the alloy to a heat treatment consisting of solution heating between 780 and 880 degrees C. ### Claim 25 (depends on 18) A method as defined in claim 18 further comprising the step of forming the alloy into an eyeglass part.