Abstract: Plastic deformation of TiAI and TiAI-V intermetallic compounds has been studied by com- pression experiment at various temperatures and strain rates.Results show that the plastic deformation in distinct temperature range is principally controlled by the mechanisms of Peierls-Nabarro,cross slip and creep of dislocations.For TiAI-V alloy deformed at a range of 600—700 K,the negative strain rate dependence of flow stress was observed,i.e.,the more the plastic strain is.the more the negative dependence will be.A possible mechanism of the anomaly could be interpreted by thermal activation of dislocation cross slipping.The effects of temperature and strain rate on work-hardening exponent were also studied and discussed.

Key words: TiAl, intermetallic compound, strain rate, cross-slip