Phase Relations Of Al-Ti-Zr Ternary System

Abstract:Ti-based alloys have excellent properties, e.g. relatively high specific strength, good oxidation resistance, good corrosion resistance, superior weldability, playing important roles in various fields, such as: aerospace materials, biomedical materials, ship materials as well as medicine and energy industry. Ti-based alloys are usually diffusion boned with other materials in application. The stability and reliability of the interface are vital to the joints, so it is of great importance to investigate the intermediate phases and their evolution at interface. In this work, phase relations of Al-Ti-Zr system are studied by combining diffusion couple technique and equilibrated alloy technique; interfacial reactions of TiAl alloys and Cu/Zr are investigated by diffusion couple technique.1. The isothermal section at1273K of the Al-Ti-Zr system was determined using equilibrated alloys. No ternary compound was detected. Experimental results show that there is a continuous solid solution P(Ti, Zr) which dissolves up to25.5at.%Al, and Ti can substitute Zr in most Al-Zr binary intermediate phases to a certain degree. Remarkable large solubility of Ti was identified in the (Zr, Ti)5Al3phase to be32.0at.%. The isothermal section consists of14three-phase regions,26two-phase regions and16single-phase regions.2. The isothermal section at1073K of the Al-Ti-Zr system was determined by combining diffusion couple and equilibrated alloys. Experimental results show that there is a continuous solid solution P(Ti, Zr) which dissolves up to16.3at.%Al, and Ti can substitute Zr in most Al-Zr binary intermediate phases to a certain degree. The isothermal section consists of14three-phase regions,27two-phase regions and16single-phase regions.3. Interfacial reactions in Ti-Al/Cu、Zr diffusion couples annealed at773K for5days and10days were experimentally studied.