Method of producing an implant

Abstract

A method for producing an implant, such as an intraluminal endoprosthesis, the method including producing a melt with a material composition of iron, sulfur at a concentration of more than 0.2% by weight and not more than 1% by weight, and at least one element selected from the group consisting of calcium, manganese and magnesium; producing a slab by cooling the melt in a mold at a predetermined cooling rate to produce a semi-finished part; and post-processing the semi-finished part to form the desired shape of the implant body.

What is claimed is: 
     
         1 . A method for producing an implant, optionally an intraluminal endoprosthesis, the body of which comprises at least predominantly a material with iron as the main constituent, comprising the following steps:
 a) producing a melt with a material composition comprising iron as a main constituent, sulfur as first minor constituent with a concentration of more than 0.2% by weight and not more than 1% by weight, optionally not more than 0.5% by weight, and a second minor constituent of at least one element selected from the group consisting of calcium, manganese and magnesium;   b) producing a slab by cooling the melt in an adequate mold at a predetermined cooling rate and, optionally, carrying out at least one hot forming step for producing a semi-finished part; and   c) post-processing the semi-finished part or slab, optionally by laser cutting, until the desired shape of the implant body is produced.   
     
     
         2 . The method of  claim 1 , wherein the second minor constituent is manganese, characterized in that the manganese is at least 0.5% by weight and not more than 3% by weight. 
     
     
         3 . The method of  claim 1 , wherein the second minor constituent is magnesium, characterized in that the magnesium is at least 0.3% by weight and not more than 1% by weight. 
     
     
         4 . The method of  claim 1 , further comprising oxygen at a concentration of 0.05% by weight and not more than 2% by weight and phosphorous at a concentration of 0.05% by weight and not more than 0.5% by weight. 
     
     
         5 . The method of  claim 1 , characterized in that cooling rate used in step b) is in a temperature range between 1200° C. and 700° C., and optionally at least 50 K/min and not more than 100 K/min. 
     
     
         6 . The method of  claim 1 , characterized in that the temperature for the hot forming step is above 550° C. and 900° C. 
     
     
         7 . The method of  claim 1 , characterized in that between steps b) and c), a tempering step is carried out optionally in a temperature range of 570° C. to 590° C., optionally over a holding time of 30 minutes for a semi-finished part in the form of a thin-walled tube. 
     
     
         8 . The method of  claim 1 , characterized in that subsequent to step c), a coating, optionally a coating containing a pharmaceutically active substance, is applied onto the implant body. 
     
     
         9 . The method of  claim 1 , characterized in that the semi-finished part is shaped to form an intraluminal endoprosthesis. 
     
     
         10 . The method of  claim 1 , further comprising carbon at a concentration of 0.1% by weight and not more than 0.5% by weight. 
     
     
         11 . The method of  claim 1 , further comprising chromium at a concentration of about 1% by weight.