双磨粒微切削单晶γ-TiAl合金的材料去除机制研究

Study on material removal mechanism of single crystal γ- TiAl Alloy by double abrasive micro cutting

摘要:

为了分析磨削过程中单晶γ-TiAl合金的材料去除机制，建立了双磨粒磨削Ti-Al合金的分子动力学模型。揭示了金刚石磨粒的横向间距和纵向间距对单晶γ-TiAl合金材料去除机制的影响。研究结果表明：单晶γ-TiAl合金的微切削过程中伴随有温度、势能、位错的变化以及晶格结构的转变；切削力、切削温度、势能以及去除效率随着横向间距的增加而增大，但受纵向间距的影响较小；晶格转变的原子数随横向间距的增加而增大，随纵向间距的增加而减小；随着横向间距和纵向间距的增加，位错数量、位错总长度以及位错密度会相应增大。

Abstract:

In order to analyze the material removal mechanism of single crystal γ-TiAl alloy in grinding, the molecular dynamics model of Ti-Al alloy ground by two abrasive grains was established. The influence of lateral and longitudinal spacing of the diamond abrasive on the material removal mechanism of the single crystal γ-TiAl alloy was revealed. The results showed that the microcutting process of single crystal γ-TiAl alloy is accompanied by the change of temperature, potential energy and dislocation, as well as lattice phase transition. Cutting force, cutting temperature, potential energy and removal efficiency increase with the increase of lateral spacing, but are less affected by longitudinal spacing. The number of lattice phase transition atoms increases with the increase of lateral spacing and decreases with the increase of longitudinal spacing. With the increase of laterial and longitudinal spacing, the number of dislocations, total length of dislocations, and density of dislocations will increase accordingly.