Methods for counteracting rebounding effects during solid state resistance welding of dissimilar materials

A multi-segment guidewire, the guidewire comprising:

• a first elongate portion of a first material, the first elongate portion comprising a smooth and flattened distal-most end;
• a second elongate portion of a second material having a higher modulus of elasticity than a material of the first elongate portion, the second elongate portion comprising a smooth and flattened proximal-most end;
• a solid-state deformation region including a junction of the distal-most end and the proximal-most end, each being free of any oxide layers, a distal end of the first elongate portion and a proximal end of the second elongate portion are joined without melting of the first material and the second material,
• wherein a heat affected zone is formed in the solid-state deformation region, the heat affected zone having an average thickness across the junction of the first elongate portion and the second elongate portion of less than about 0.20 mm, the heat affected zone having a first thickness toward a center of the solid-state deformation region, and in a direction aligned with a longitudinal axis of the multi-segment device, that is less than a second thickness toward a perimeter of the solid-state deformation region, and in the direction aligned with the longitudinal axis of the multi-segment device.