Techniques are disclosed related to wires that may be used within a medical device. According to one example, a wire may include a core formed of a material having a resistivity of less than 25 micro-ohm-cm and a layer of a biocompatible beta titanium alloy surrounding the core. As one example, the beta titanium alloy has an elastic modulus ranging from 30 GigaPascals (GPa) to 90 GPa and comprises at least two elements from a group consisting of titanium, molybdenum, niobium, tantalum, zirconium, chromium, iron and tin. In one embodiment, the core may be formed of silver, tantalum, a tantalum alloy, niobium, a niobium alloy, platinum, a platinum alloy, palladium, or a palladium alloy. In some examples, one or more wires may be incorporated into a coil or a cable and one or more such coils or cables may be carried by a medical device such as a medical electrical lead.