Investigating the effect of the addition of WC into NiTi for stent application

Abstract

Abstract. Nitinol is used for self-expandable stents used in biomedical applications considering their excellent properties of being superelastic and biocompatible. Minimally invasive implants need to be securely positioned in the human body with the property of being visible with the help of X-rays. Limited radiopacity of nitinol implants requires additional markers on the implants to facilitate accurate placement of the implant. This study explores the path of adding different concentrations of tungsten carbide (WC) to nickel-rich nitinol powder. Tests were conducted by compacting the mixed powders with a hydraulic press and then furnace sintering the green samples, with varying pressures and temperatures, to produce the solid parts. The mechanical properties of density and hardness of the sintered samples were measured and compared. An increase in hardness from 76 HV to 150 HV indicated that better mechanical properties could be achieved. Fully dense samples without any pores were obtained. These results show potential for the introduction of WC to nitinol for additively manufactured parts.