Fort Wayne Metals Research Products Corporation

Adam J Griebel

Jeremy E Schaffer

Song Cai

Jeremy E Shaffer

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.

Magnesium-based absorbable alloys

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.

Nickel-titanium-yttrium alloys with reduced oxide inclusions

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.

Growing community of inventors

Fort Wayne, IN, United States of America

Adam J Griebel