Abstract: A magnesium alloy contains a small amount of lithium, zinc, calcium, and manganese. For example, the magnesium alloy may include between 1-5 wt. % lithium, between 0.2-2.0 wt. % zinc, between 0.1-0.5 wt. % calcium, and between 0.1-0.8 wt. % manganese. These alloying elements are all nutrient elements, such that the present alloy can be safely broken down in vivo, then absorbed and/or expelled from the body. Li, Zn, Ca and Mn each contribute to solid-solution strengthening of the alloy. Ca also acts as a grain refiner, while Zn and Ca both form strengthening and corrosion-controlling intermetallic compounds. Optionally, the alloy may also include a small amount of yttrium for added strength and corrosion resistance.

Abstract: A nickel-titanium alloy is made to be wholly or substantially free of titanium-rich oxide inclusions by including yttrium in an amount up to 0.15 wt. %, with the balance of the alloy being nickel and titanium in approximately equal proportion. For example, a NiTiY alloy may have a composition including, in weight percent based on total alloy weight: between 50 and 60 wt. % nickel; between 40 and 50 wt. % titanium; and between 0.01 and 0.15 wt. % yttrium. The resulting alloy is capable of being drawn into various forms, e.g., fine medical-grade wire, without exhibiting an unacceptable tendency to develop surface defects or to fracture or crack during cold drawing or forging. The resulting final forms exhibit favorable fatigue strength and fatigue-resistant characteristics.

Abstract: A nickel-titanium alloy is made to be wholly or substantially free of titanium-rich oxide inclusions by including yttrium in an amount up to 0.15 wt. %, with the balance of the alloy being nickel and titanium in approximately equal proportion. For example, a NiTiY alloy may have a composition including, in weight percent based on total alloy weight: between 50 and 60 wt. % nickel; between 40 and 50 wt. % titanium; and between 0.01 and 0.15 wt. % yttrium. The resulting alloy is capable of being drawn into various forms, e.g., fine medical-grade wire, without exhibiting an unacceptable tendency to develop surface defects or to fracture or crack during cold drawing or forging. The resulting final forms exhibit favorable fatigue strength and fatigue-resistant characteristics.

Abstract: A group of substantially nickel-free beta-titanium alloys have shape memory and super-elastic properties suitable for, e.g., medical device applications. In particular, the present disclosure provides a titanium-based group of alloys including 16-20 at. % of hafnium, zirconium or a mixture thereof, 8-17 at. % niobium, and 0.25-6 at. % tin. This alloy group exhibits recoverable strains of at least 3.5% after axial, bending or torsional deformation. In some instances, the alloys have a capability to recover of more than 5% deformation strain. Niobium and tin are provided in the alloy to control beta phase stability, which enhances the ability of the materials to exhibit shape memory or super-elastic properties at a desired application temperature (e.g., body temperature). Hafnium and/or zirconium may be interchangeably added to increase the radiopacity of the material, and also contribute to the superelasticity of the material.

Abstract: A nickel -titanium alloy is made to be wholly or substantially free of titanium-rich oxide inclusions by including yttrium in an amount up to 0.15 wt. %, with the balance of the alloy being nickel and titanium in approximately equal proportion. For example, a NiTiY alloy may have a composition including, in weight percent based on total alloy weight: between 50 and 60 wt. % nickel; between 40 and 50 wt. % titanium; and between 0.01 and 0.15 wt. % yttrium. The resulting alloy is capable of being drawn into various forms, e.g., fine medical-grade wire, without exhibiting an unacceptable tendency to develop surface defects or to fracture or crack during cold drawing or forging. The resulting final forms exhibit favorable fatigue strength and fatigue-resistant characteristics.

Abstract: A group of substantially nickel-free beta-titanium alloys have shape memory and super-elastic properties suitable for, e.g., medical device applications. In particular, the present disclosure provides a titanium-based group of alloys including 16-20 at. % of hafnium, zirconium or a mixture thereof, 8-17 at. % niobium, and 0.25-6 at. % tin. This alloy group exhibits recoverable strains of at least 3.5% after axial, bending or torsional deformation. In some instances, the alloys have a capability to recover of more than 5% deformation strain. Niobium and tin are provided in the alloy to control beta phase stability, which enhances the ability of the materials to exhibit shape memory or super-elastic properties at a desired application temperature (e.g., body temperature). Hafnium and/or zirconium may be interchangeably added to increase the radiopacity of the material, and also contribute to the superelasticity of the material.

Abstract: A composite wire product includes a biodegradable parent material which forms the bulk of the cross-sectional area of the wire, and a central fiber or filament of a slower-degrading or non-biodegradable material runs throughout the length of the wire. This central filament promotes the mechanical integrity of an intraluminal appliance or other medical device made from the wire product throughout the biodegradation process by preventing non-absorbed parent material from dislodging from the central filament. Thus, the present wire design enables the creation of medical devices that are designed to improve in flexibility toward a more natural state over the course of healing, while also controlling for the possibility of non-uniform in vivo erosion.

Abstract: A bioabsorbable material composition includes magnesium (Mg), lithium (Li) and calcium (Ca). Lithium is provided in a sufficient amount to enhance material ductility, while also being provided in a sufficiently low amount to maintain corrosion resistance at suitable levels. Calcium is provided in a sufficient amount to enhance mechanical strength and/or further influence the rate of corrosion, while also being provided in a sufficiently low amount to preserve material ductility. The resultant ductile base material may be cold-worked to enhance strength, such as for medical applications. In one application, the material may be drawn into a fine wire, which may be used to create resorbable structures for use in vivo such as stents.