在Z形扫描轨迹换向处，其热积累较严重，较高的温度引发了较大的热膨胀变形和较大的热应力。随着激光加热结束，系统逐渐冷却收缩，可以发现Z形扫描方式最终稳定的热应力和热变形都要明显小于单向扫描方式（热变形由1.60 μm减小到1.16 μm，热应力由468 MPa减小至438 MPa）。

The heat accumulation is more serious at the direction reversal of the Z-scan track, and the higher temperature leads to larger thermal expansion deformation and larger thermal stress. With the end of laser heating, the system gradually cools and shrinks. It can be found that the final stable thermal stress and thermal deformation of Z-scanning mode are significantly smaller than those of unidirectional scanning mode (the thermal deformation decreases from 1.60μm to 1.16μm, and the thermal stress decreases from 468MPa to 438MPa).