【摘要】 利用光学显微镜及透射电镜考察了β′Cu-Zn合金中温区等温转变。发现其转变产物平衡相α与贝氏体α₁在TTT图中具有各自独立的C曲线。在两C曲线交叉点温度以下的转变初期,可得到单相的亚稳贝氏体α₁,而延长等温时间,α₁将部分甚至完全退化为α。初期形成的α₁内部具有完整的层错亚结构,其体转变激活能仅约为Zn扩散激活能的1/2。更多还原

【Abstract】 The isothermal transformation within the medium temperature range in a β’Cu-Zn alloy is investigated by optical microscope and TEM. The equilibrium phase α and the bainite α1 possess their own C-curves. The metastable single-phase bainite α1 can be obtained only at the early stage below the intersection of the two C-curves. α1 may degenerated into α partially or completely during longer isothermal transformation. The bainite el formed at early stage has stacking faults and its overall activation energy is only one half of the diffusional activition energy of zinc, which infers that the β’→α1 reaction in a Cu-Zn alloy should be carried out by shear mechanism.更多还原