Medical instruments and devices and parts thereof using shape memory alloys
AssigneeMemry Corporation
InventorsWilfried Van Moorleghem, Anja Serneels, L. McDonald Schetky
Life of this patent
Estimating the term…
Abstract
Fabrication of metal medical instruments and devices from a shape memory alloy which provides greater flexibility in design and avoids the need for substantial cold working of the alloy which is required in other methods. The new process provides a ductile alloy for ease of forming and a unique heat treatment which renders the fabricated orthodontic and medical components highly elastic, with a high resistance to kinking and with good corrosion resistance. In addition, this new process produces orthodontic and medical components useful over the temperature range of from −20 to +40 degrees C.
Claims24
In a medical or orthodontic component or device having at least a portion thereof fabricated from Ni—Ti based shape memory alloy, the improvement comprising:
- (a) said alloy being more than 50 atomic % nickel;
- (b) said alloy having been solution treated at a temperature of 650 to 1100° C. for 10-60 minutes;
- (c) after cooling, said alloy having been aged by heating it at a temperature of approximately 350° C. for 10-60 minutes;
- (d) said portion being characterized by:
- (i) having pseudoelastic properties without cold working,
- (ii) having greater than 2.5% elasticity over a temperature range of −20° C. to +40° C., and
- (iii) allowing large plastic deformations during the fabrication of said portion.
A method of making at least a component of a medical or orthodontal instrument or device, comprising:
- (a) fabricating said component of an alloy which includes
- (i) an alloy of NiTi with a higher nickel content than an equiatomic Ni/Ti ratio in a Ni—Ti shape memory alloy,
- (ii) and which has been solution treated at a temperature of 650 to 1100° C. for 10-60 minutes;
- and
- (b) aging said component after it is fabricated, by heating it at a temperature of approximately 350° C. for 10-60 minutes,
- said portion being characterized by:
- having pseudoelastic properties without could working,
- having greater than 2.5% elasticity over a temperature range of −20° C. to +40° C., and
- allowing large plastic deformations during the fabrication step before the desired pseudoelastic properties are established.
Dependencies are inferred from the claim text.