Corrosion resistance of a laser spot-welded joint of NiTi wire in simulated human body fluids.
The purpose of this study was to investigate corrosion resistance of a laser spot-welded joint of NiTi alloy wires using potentiodynamic tests in Hank's solution at different PH values and the PH 7.4 NaCl solution for different Cl- concentrations. Scanning electron microscope observations were carried out before and after potentiodynamic tests. The composition of a laser spot-welded joint and base metal were characterized by using an electron probe microanalyzer. The results of potentiodynamic tests showed that corrosion resistance of a laser spot-welded joint of NiTi alloy wire was better than that of base metal, which exhibited a little higher breakdown potential and passive range, and a little lower passive current density. Corrosion resistances of a laser spot-welded joint and base metal decreased with increasing of the Cl- concentration and PH value. The improvement of corrosion resistance of the laser spot-welded joint was due to the decrease of the surface defects and the increase of the Ti/Ni ratio.
Yan
Xiao-Jun
XJ
Department of Materials Engineering, Dalian University of Technology, Liaoning, Dalian, 116024, People's Republic of China. dreamto2008@sohu.com
Yang
Da-Zhi
DZ
D000497:Alloys / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001826:Body Fluids / Q000737:chemistry*; D003343:Corrosion; D004563:Electrochemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007834:Lasers; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry*; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
D000497:Alloys; D001672:Biocompatible Materials; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium