分析研究了双相TiAl基合金室温塑性变形的协调问题,表明γ相中易开动的变形系统少,不能满足多晶体塑性变形协调的必要条件是这类合金室温塑性差的主要原因.在此基础上,分析了这类合金室温塑性与晶粒尺寸的关系,表明拉伸断裂应变(ε_f)与晶粒直径间的关系可近似描述为ε_f=a/(d+b). The coordination problem of room temperature plastic deformation of TiAl-based alloys is analyzed and studied. It is found that the reason that room temperature plasticity of these alloys is poor is the necessary condition that the deformation system of γ phase is not easy to start and can not meet the requirements of plastic deformation of polycrystalline. , The relationship between room temperature plasticity and grain size was analyzed. It is shown that the relationship between tensile strain (ε_f) and grain diameter can be approximated as ε_f = a / (d + b).