Microstructural and tribo-mechanical investigation of as-cast Ti-Zr binary alloys

Abstract

Titanium and its alloys are proved to be very successful in manufacturing of various types of automotive and aircraft parts. It is also used in manufacturing of some sophisticated medical instruments and medical implants purposes. Investigated titanium binary alloys in this research were Ti-5Zr and Ti-20Zr respectively. The casting process was used in an electric arc furnace to produce titanium alloys with addition of zirconium content (5% and 20%) in two different proportions separately. The primary aim of this research work was to evaluation of microstructural characterization and investigation of tribo-mechanical properties. XRD method was used to analyze present phases and both alloys showed martensitic hcp α' Ti structures complied with α Ti structures. FESEM was engaged to study microstructures and EDS showed that analyzed alloys have identical chemical compositions. Microhardness property was improved with the increment in Zr concentration. Resulted hardness for Ti-5Zr alloy was 305HV, while hardness was increased to 316HV for Ti-20Zr alloy. Tribological properties of binary Ti-Zr alloys were assessed with the help of a typical ball on plate set under the dry condition and at room temperature. In this case also higher Zr contain Ti binary alloy favored better tribological effects and this can be attributed from resulted COF values of Ti-Zr binary alloys. At the low load (15 N), COF values were 0.35 and 0.29 for Ti-5Zr and Ti-20Zr alloys respectively. Whereas at the high load (30 N), COF values were 0.36 and 0.34 for Ti-5Zr and Ti-20Zr alloys respectively. However, it was quite evident that adhesive wear was dominant for these Ti-Zr binary alloys.