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A D V A N C E D M A T E R I A L S & P R O C E S S E S | O C T O B E R 2 0 1 9 5 0 FEATURE element, superelastic tip, and a joint method to combine stainless steel with nitinol. The possibility of integrated high strength and superelastic properties in a single wire can elim- inate the need for device-level joint construction (e.g., Pal- ermo’s solder and glue [7] ), quality inspection overhead, and potentially less continuous property and handling transition. To explain briefly, the taper shown in Fig. 1was applied to the example herewith good results in “felt” property transition down the length of the core wire. The prototype composite wire discussed here is further distinct from results of Jalisi [8, 9] in that the core wire comprises only two elements with a su- perelastic core rather than a relatively stiff one. CONCLUSION Results of thiswork show it is possible to integratedissim- ilar metals to achieve a functionally driven design. While the 35N LT and Nitinol combination performs well, other materials can be successfully combined. Table 1 shows a variety of ma- terials and their purpose where performance can be realized across high-strength species and relatively elastic species with integration into a single composite wire. ~SMST Formore information: Jeremy Schaffer is director of research and development, Fort Wayne Metals, 9609 Ardmore Ave., Fort Wayne, IN 46809, 260.747.4154, email: jeremy_schaffer@ fwmetals.com , fwmetals.com . DFT wire and 35N LT are registered trademarks of Fort Wayne Metals. MP35N is a registered trademark of SPS Tech- nologies Inc. TABLE 1 − DFT MATERIAL COMBINATION POSSIBILITIES TO COMBINE DISTINCT HIGH STRENGTH AND ELASTIC PROPERTIES Possible tube materials Purpose Possible core materials Purpose CoCr (e.g., L605) High strength and elastic stiffness, corrosion and fatigue damage resistance Nitinol Superelasticity, torque response, kink resistance CoNiCr (e.g., MP35N, 35NLT, FWM 1058) High strength and elastic stiffness, corrosion and fatigue damage resistance Nitinol ternary alloy (e.g., NiTiHf, NiTiZr, NiTiNb, NiTiCo, NiTiCr Relative high stiffness/ plateau superelaticity, torque response, kink resistance Refractory metals including W-Re, Mo-Re, W, and Rh High strength and elastic stiffness, stress fatigue damage resistance Superelastic Beta-Ti alloy (e.g., TiNbZrSn, Ti-Ta, Ti-Mo) Superelasticity, torque response, tissue compatibility, kink resistance Titanium alloys (e.g., CP Ti, Ti 6-4, Ti Beta C, Ti Beta III) Tissue compatibility, high strength, fatigue damage resistance Multielement array of superelastic alloys including Ni-Ti, NiTi-X-, NiTi-X-Y, and Ti-Beta Configurability, superelasticity, kink resistance, deployability Platinum alloys including Pt-Ir Tissue compatibility, electrocorrosion resistance at tissue interface, high elastic stiffness References 1. R.J. Warren, et al., Coronary Angioplasty for Chronic Total Occlusion Reduces the Need for Subsequent Coronary Bypass Surgery, Amer. Heart Jour. , 120.2, p 270-274, 1990. 2. S.D. Tomasello, et al., The Innovation of Composite Core Dual Coil Coronary Guide-Wire Technology: A Didactic Coro- nary Chronic Total Occlusion Revascularization Case Report, J. Saudi Heart Assoc., 26.4, p 222-225, 2014. 3. G. Sianos, et al., Theory and Practical Based Approach to Chronic Total Occlusions, BMC Cardiovascular Disorders, 16.1, p 33, 2016. 4. J.A. Schaffer, E.A. Nauman, and L.A. Stanciu, Cold-Drawn Bioabsorbable Ferrous and Ferrous CompositeWires: An Eval- uation of Mechanical Strength and Fatigue Durability, Metall. Mater. Trans. B, 43.4, p 984-994, 2012. 5. R.M. Abrams, et al., Guidewire with Superelastic Distal Portion, U.S. Patent No. 5,341,818, 30 Aug 1994. 6. B. Reynolds, et al., Composite Guidewire, U.S. Patent No. 7,074,197, 11 July 2006. 7. T.J. Palermo, et al., Super-Elastic Composite Guidewire, U.S. Patent No. 5,769,796, 23 June 1998. 8. M.M. Jalisi, et al., Guidewire Having Braided Wire Over Drawn Tube Construction, U.S. Patent No. 6,142,975, 7 Nov 2000. 9. M.M. Jalisi, et al., Composite Guidewire Withdrawn and Filled Tube Construction, U.S. Patent No. 8,226,577, 24 July 2012. 1 2