Patent ID: 8916091

Claim:
A method for producing a semi-finished product for producing a stent, the semi-finished product being obtained from a shape memory alloy, comprising the following steps: producing a powder from the shape memory alloy by gas atomization, separating the produced powder based on particle size into a first group of particles having a size range up to a first size and a second group having a size range greater than said first size, said first size being at least 75 μm; separating the second group of particles into a third group of particles having a size range between said first size and a second size and a fourth group of particles having a size range greater than the second size, said second size being between 100 μm and 150 μm, the third group having a distribution of particles between said first size and said second size; filling the third group of particles into an hot isostatis pressing (HIP) capsule comprising an outer tube having an inner tube disposed centrally therein and compacting said fraction, and subjecting the HIP capsule to an HIP process, thereby producing the semi-finished product, said semi-finished product being tubular, wherein the shape memory alloy is a NiTi alloy having a ratio of Ni to Ti between 45 atom % to 55 atom % and 55 atom % to 45 atom %, the NiTi alloy comprising a further alloying element selected from Cu, Nb, Zr, Pt or Pd.