Effect of copper on the localized corrosion resistance of Ni-Ti shape memory alloy.
An electrochemical study aiming at the evaluation of corrosion parameters using potentiodynamic and potentiostatic techniques ("scratch" and modified ASTM F746) was conducted in 0.9% NaCl on wires from equiatomic Ni-Ti and ternary Ni44Ti51Cu5 superelastic alloys with Ti90Mo10 as a reference material. The results obtained using potentiostatic tests, that simulate better the behavior of material in service conditions than potentiodynamic ones, indicate that both Ni-Ti and Ni-Ti-Cu wires exhibit low corrosion potentials (approximately 50-150 mV versus SCE) inferior to that of Ti-Mo alloy. The latter proved to be immune to localized corrosion attacks up to 800 mV.
Rondelli
G
G
CNR-TEMPE, Milano, Italy. rondelli@tempe.mi.cnr.it
Vicentini
B
B
D000497:Alloys; D003300:Copper / Q000737:chemistry*; D003343:Corrosion; D004355:Drug Stability; D004548:Elasticity; D004563:Electrochemistry / Q000379:methods; D009532:Nickel / Q000737:chemistry*; D011199:Potentiometry / Q000379:methods; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*
D000497:Alloys; C040654:titanium nickelide; D003300:Copper; D009532:Nickel; D014025:Titanium