One of the most important alternative groups of material for super alloys, are titanium aluminides. Some properties like high melting point, high resistance to oxidation, creep and corrosion, high strength from room temperature to high temperature, low density and high strength to weight ratio cause these intermetallics have a specific position for application in aerospace and power plant. There are two major methods for the production of these compounds. The first one is liquid synthesis methods that have some limitations like high temperature and energy as a result of high melting point of Ti. The second one is solid synthesis methods. The most usual solid method is mechanical alloying. However this method doesn't need high temperature but it has some limitations like low capacity of mills, long time of process and subsequent heat treatments. So the main purpose of this research is investigated for the method of production of TiAl that contains both thermal and mechanical activation simultaneously, by using high temperature ball milling. In this research, pure powders of Ti and Al are mixed by stoichiometric ratio in range of the formation of TiAl compound. This mixture was milled in 700, 800 and 900°C (between melting points of Al and Ti) for times of 6, 12 and 18 hours. In order to investigating the effect of temperature and time, XRD, SEM and EDS tests were conducted on reaction products. Then for investigating about the mechanism of this process, some tests like DTA and isothermal test were used. According to the results of this project, TiAl intermetallic was achieved by 18 hours milling of 50%at.Ti- 50%at.Al powder mixture at 900°C. Finally, the results are shown that the first producted compound is Al 3 Ti. After that other Ti-Al intermetallics will form by diffusion. Therefore, the most important parameter in forming of TiAl is diffusion coefficient. Key words Titanium Aluminides, Thermal Activation, Mechanical Activation, Hot milling
