Bidirectional improvement of strength and ductility of CoCrFeNiTi (Co40Cr16Fe35Ni8Ti1) high-entropy alloys suitable for coronary stents

Bio-high entropy alloys: Progress, challenges, and opportunities

“…Chen et al ( Chen S. M. et al, 2022 ) used the first-principles approach combined with a thermodynamic model to study phase decomposition in alloys by considering HEA as various pseudo-binary systems, as shown in Figure 10 , which predicts that phase decomposition in Hf-Nb-Ti-Zr alloys with a BCC structure occurs at temperatures below the critical temperature of 1298 K. The HEA decomposes most favorably into NbTa-rich and HfZr-rich BCC phases, while the BCC-rich HfZr phase is transferred to the hexagonal compact stacking structure (HCP) phase at low temperatures. ( Chen X. et al, 2022 ; Chen Z. W. et al, 2022 ). In addition, the effects of solid solution and precipitation strengthening mechanisms on the strength of HEA were calculated based on the predicted phase decomposition results, combined with experimental data.…”

Research progress of metal biomaterials with potential applications as cardiovascular stents and their surface treatment methods to improve biocompatibility

“…The study found that the high-entropy alloy either approached or outperformed 316L SS in various mechanical properties, exhibiting higher fatigue life, which was beneficial for reducing the failure rate of stent implants. Chen et al [ 59 ] designed a new Co 40 Fe 35 Cr 16 Ni 8 Ti 1 HEA for coronary stents, which met the mechanical property and corrosion resistance requirements of common coronary stent materials on the market. This alloy exhibited good elongation and its yield strength and tensile strength reached 588 and 932 MPa, respectively, offering novel insights for the development of high-performance coronary stent materials.…”