<p>Due to the intrinsic brittleness of γ-TiAl alloy, defects and residual stresses are easily introduced during processing, significantly affecting its service performance. To reveal the plastic deformation mechanism during machining, this study employed nanoscratching experiments and crystal plasticity finite element (CPFE) simulations to investigate the effect of scratch parameters and grain boundaries on the nanoscratching behavior of bicrystalline γ-TiAl alloy. The variation mechanisms of scratch force and depth, the distribution of cumulative shear strain under different normal loads, and the plastic deformation behavior at each grain boundary were examined. The results indicate that higher normal loads lead to greater scratch forces and depths, while higher scratch speeds result in reduced scratch forces and depths. The mechanical response at grain boundaries undergoes abrupt changes due to different crystal orientations between adjacent grains. There is a pronounced interaction between cumulative shear strain and grain boundaries; the influence of grain boundaries becomes more significant with increasing load. A higher scratch speed aids in reducing material wear. The interaction between dislocations and grain boundaries, and the type of grain boundary, substantially alters the plastic deformation during scratch. These research results support high-quality surface processing of γ-TiAl alloy and improve its performance.</p> Graphical Abstract <p></p>