Investigation of Microstructure and Corrosion of TiNbTaZrMo High-Entropy Alloy in the Simulated Body Fluid

摘要

Microstructures and corrosion of TiNbTaZrMo(Ti_(20)Nb_(20)Ta_(20)Zr_(20)Mo_(20))High-Entropy Alloy(HEA)were investigated in the Simu-lated Body Fluid(SBF).Microstructure of this alloy was investigated by X-Ray Difiraction(XRD)and Scanning Electron Microscopy(SEM)techniques.Our observations confirmed the presence of two bcc phases as the major matrix as well as another minor phase in themicrostructure of the alloy.Concentration of some elements,such as tantalum,niobium,and molybdenum in the dendritic branches and thepresence of zirconium and titanium in the inter-dendritic branches were clearly evidenced by Energy Dispersive X-ray(EDX)analysis.Given importance of corrosion of implant alloys in the human's body,elctrochemical impedance and cyclic polarization tests werepcerformed on the alloy in SBF.Through the corrosion tests,corrosion potential,current,and resistance were obtained as E_(corr)=-0.42 V,i_(corr)=0.34μA·cm^(-2),and R_(p)=27.44 k ohm·cm^(2),respectively.The results revealed that the rate of corrosion in TiNbTaZrMo HEA is about 26 times better than that of Ti_(6)Al_(4)V alloy.Also,both alloys had no pitting corrosion in the SBF solution.