关键词: 镍基单晶高温合金, 分子动力学, 铣削力, 各向异性, 表面质量

Abstract: In order to research the milling force characteristics of DD5 Ni-based single crystal superalloy with crystallographic anisotropy, based on the molecular dynamics simulation, P-N force calculated expression, directional cutting method and slot milling experiments, and based on the preliminary exploration on single crystal alloy milling deformation mechanism, the milling forces along the feed direction of tools were qualitatively modeled, the slot bottom surface quality milled along the different crystal directions on the (001) crystal plane were evaluated. The research results show that the single crystal material removal is depended on the stacking fault structure destruction and chip atoms climb along the slip system, and the milling starts to enter into the stable processes when the bulk stacking fault structures are destoried. Based on the slip system and effective resolved shear stress theories, it is found that the milling force are fluctuated between the range of 18~27 N, the milling force, surface roughness, the adjacent tool feed track spacing and micro peak-valley height difference increase from the crystal direction ［110］ to ［470］, ［100］ and ［740］, ［010］. Therefore, during the milling processes of DD5 Ni-based single crystal superalloy, the milling along the ［110］ crystal direction may show the best performance.

Key words: Ni-based single crystal superalloy, molecular dynamics, milling force, anisotropy, surface quality