Corrosion Behavior of Ti-55Ni-1.2Co High Stiffness Shape Memory Alloys

Effect of cobalt addition on the corrosion behavior of near equiatomic NiTi shape memory alloy in normal saline solution: electrochemical and XPS studies

“…25 Application of NiTi alloys in medical device is a result of their high corrosion resistance and biocompatibility in combination with increased modulus and high stiffness, as already highlighted. 26 Furthermore, Fasching et al 27 investigated NiTi alloys containing 1-2% of cobalt and revealed that in comparison to NiTi alloys, NiTiCo has approximately 30% higher modulus, loading plateau and unloading plateau with similar biocompatibility and no reactivity in both investigated tests, namely: cytotoxicity and hemolysis. The yield strength improvement was also conrmed for NiTi alloys containing 2-10% Co addition.…”

“…29 In order for these alloys to be successfully used, the effect of cobalt on the corrosion resistance properties must be well dened. Huang et al 26 investigated the corrosion properties of these alloys in PBS solution, claiming similar behavior to cobaltless NiTi alloys and no effect of galvanic corrosion within stent. These studies however were carried out in mild environment, where pitting or crevice corrosion is not to be expected.…”

Effect of cobalt addition on thermal cycling behaviour of Ti50Ni(50−x)cox shape memory alloys

“…In contrast, the corrosion resistance of these alloys is impaired due to iron addition. In this context, NiTiCo alloys are more appropriate for this kind of application as adding Co does not in any way impair the corrosion behaviour of the binary NiTi SMAs [17][18][19].…”

Investigation and Composition Characterization of a “NiTi-like” Alloy Combining High Temperature Shape Memory and High Entropy

“…Indeed, their operating performances as functional and active materials are recognized and mastered [12,13]. Since the 2000s, the properties of this binary alloy have been improved by studying NiTi-X alloys when X can substitute Ni by Co, Cu, Pd, Pt [14][15][16][17], or substitute Ti by Hf, Zr [18][19][20] or both by Nb, Ta, Au [16,21,22].…”