Microstructural characters of TiAl intermetallics prepared with different processes

Fine-grain Ti/Al composite powder was prepared by mechanical alloying. TiAl intermetallics with various grain sizes were prepared by different compacting methods and reaction sintering as well as isothermal forging. The microstructural characters of TiAl alloys were analyzed. The effects of different processes on microstructures of TiAl intermetallics were studied. The results indicate that the processing of cold isostatic pressing, reaction sintering at 630°C and isothermal forging can effectively reduce the grain size of Ti/Al alloys, and the grain size of the TiAl intermetallics is between 5 and 8 μm. The lamellar TiAl intermetallics, which are nearly fully dense, can also be obtained by common cold pressing, reaction sintering at 1250°C and isothermal forging, but the grain size is 20~30 μm.