为了考察纳秒激光脉冲宽度对激光加工中熔体体积的影响。基于双温方程, 采用有限元方法, 考虑激光的时空分布, 数值模拟了高斯分布的纳秒脉冲激光辐照1060铝合金表面时, 微坑中熔体体积随脉冲宽度的变化。在低能量密度条件下, 轴向辐照中心下方0~0.4 μm的区域内, 脉冲宽度较小的激光产生的晶格温度高于脉冲宽度较大的激光辐照产生的温度, 而在0.4 μm以下的位置, 脉宽越小, 晶格温度越低；在所考察的脉冲宽度范围内, 中心点处熔体厚度随激光脉冲宽度的升高呈近乎正比增加。结果表明, 在脉冲宽度控制下, 纳秒激光可以控制温度场的空间分布, 而纳秒激光加工中的熔体体积可以通过控制激光脉冲的宽度来控制。这一结论可用于解释C K?rner 等人所提出的纳秒激光加工模型：激光脉冲能量的增大将导致激光与材料作用时间延长从而导致更多的熔体。同时, 将为激光微孔加工中重铸层厚度的研究提供参考。

In order to investigate the effect of nanosecond laser pulse width on melt volume in laser processing, based on the double temperature equation, the finite element method is used to consider the spatiotemporal distribution of the laser, and the volume of the melt in the micro-pit changes with the pulse width when the Gaussian pulse laser irradiation of 1060 aluminum alloy surface is numerically simulated. The results show that under the condition of low energy density, laser irradiation with small pulse width, in the area 0~0.4 μm below the axial irradiation center, the lattice temperature is higher than the temperature generated by laser irradiation with greater pulse width, and the melt thickness at the center point increases with the increase of laser width in the range of pulse width investigated. The above results show that the spatial distribution of temperature field can be controlled by nanosecond laser under the control of pulse width, and the volume of melt in nanosecond laser processing can be controlled by controlling the width of laser pulse.