Effect of Temperature on Segregation and Deformation Mechanism of α+Ti2Cu Alloy during Semi-Solid Forging

摘要:

以新型阻燃钛合金Ti14 (α＋Ti2Cu)为对象，研究了合金在不同温度半固态锻造过程中的偏析和偏聚现象及由此导致的变形机制的变化。结果表明，半固态温度影响液相含量和分布，随着温度的升高液相在晶界由不连续分布转变为连续分布析出，并最终形成了网状结构分布。锻造过程中由于液相和应力的共同作用出现了宏观偏析现象，液相在压力作用下的流动在晶界处产生了宏观液相/固相分离现象，靠近试样中心固相离子集中；这种现象导致了锻造过程中变形机制的变化，中心区仍旧是固相粒子的塑性变形为主变形机制，靠近试样外边缘主变形机制转变为固相粒子的相对滑移，通过唯象模型对其过程进行讨论

Abstract:

The segregation behavior and the deformation mechanism of Ti14, a new typical burn resistant α+Ti2Cu alloy were investigated, during semi-solid forging at different temperatures. The results reveal that semi-solid temperature will affect the content and the distribution of liquid phase evidently. Upon increasing of temperature, the liquid phase distribution transforms from discontinuity to continuity at grain boundaries, and finally a type of net-structure is formed. Moreover, the macro-segregation of liquid and solid phases occurs during the semi-solid forging, which leads to a change of the main deformation mechanism from center to edge of the sample. The relationship of macro-segregation of liquid/solid phases and the main deformation mechanism was also discussed by a phenomenological model.