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Abstract

Due to the inappropriate assumption with the neglect of evaporation effect in previous research, a linear penetration behavior with a significant deviation from the experimental result was usually proposed in the lower energy density region. To remedy the defect, the evaporation mass determined from the difference between the melting rate and flow expulsion by pressure difference is reconsider in this study. With a 2-D quasic-steady model based on the enthalpy theory, the uniform penetration velocity estimated from the Stefan boundary condition provides a special advantage in calculating efficiency. Meantime, the divergent iteration has been effectively avoided by setting up a non-uniform distribution of grids in the numerical scheme; which also enables a successful prediction of nonlinear penetration behaviors, such as the material removal rate and penetration velocity versus incident energy density. Compared with the experimental data of Allmen [1], present model shows a good agreement for copper drilling in higher energy density region (> 7 × 1010 w/m2 ), where the relative errors between the calculated and experimental data are no more than 10%. Even the linear drilling result in lower energy density region has been further improved in this study.

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