1. A stent comprising a cobalt-based alloy is disclosed. The cobalt-based alloy is free of nickel (Ni), and comprises 10-35 weight % metal member selected from the group consisting of platinum (Pt), gold (Au), iridium (Ir), osmium (Os), rhenium (Re), tungsten (W), palladium (Pd), tantalum (Ta), and combinations thereof； 16-21 weight % chromium (Cr)； 0-12 weight % molybdenum (Mo)； 0-3 weight % iron (Fe)； and balance cobalt (Co). A stent comprising a molybdenum free cobalt-based alloy is also disclosed, comprising 10-35 weight % metal member selected from the group consisting of platinum (Pt), gold (Au), iridium (Ir), osmium (Os), rhenium (Re), tungsten (W), palladium (Pd), tantalum (Ta), and combinations thereof； 20-24 weight % chromium (Cr)； 0-12 weight % nickel (Ni)； 0-3 weight % iron (Fe)； and balance cobalt (Co).
