Microstructure and Corrosion Behavior of Al-Cu-Fe Quasi-crystalline Coated Ti-6Al-4V Alloy

Different industries, including aerospace, marine, and automotive, widely use titanium alloys such as Ti-6Al-4V. Although, this alloy has excellent properties; it is highly susceptible to corrosion and has low thermal stability and tribological characteristics, limiting its application. In this research, after preparing the Al62.5Cu25Fe12.5 quasi-crystalline (QC) powder mixture and appropriate target, the magnetron sputtering method was employed to deposit the QC coating on the Ti-6Al-4V substrate. The powder mixture and AlCuFe thin films were annealed at 7000C for 2 h. The scanning electron microscope (SEM) analysis and X-ray diffraction (XRD) methods were used to investigate the microstructure and morphology of mixed powders and Al-Cu-Fe QC coatings. NaCl solution (3.5 wt.%) was utilized to conduct the electrochemical measurements. Al-Cu-Fe thin layer deposited on the Ti-6Al-4V alloy surface without any cracks. The XRD patterns related to the annealed powders and the coating after heat treatment indicated the presence of Cu3Al, AlFe3, and quasi-crystalline ternary phases of Al65Cu20Fe15, Al3Fe, AlTi2, and Al65Cu20Fe15 phases, respectively. Based on the polarization test results, the annealed coating at 700°C showed better electrochemical behavior than the Ti-6Al-4V substrate.