为了深入研究聚甲基丙烯酸甲酯(PMMA)的CO2激光辐照融化特性, 依据热传导和能量守恒原理, 建立低功率 CO2激光辐照融化理论分析模型, 解析计算CO2激光辐照融化PMMA的激光参数阈值, 分析激光参数与温度变化相互关系, 采用数码显微系统、SEM扫描电镜和XRD分析仪, 测试分析PMMA试样的融化形貌和组织特征变化。结果表明, 激光功率密度31.8~47.7 W/cm2可以满足PMMA融化且不发生热分解, 实验结果与激光融化阈值理论计算基本相符, 可为PMMA的CO2激光融化机制及其成型工艺研究提供参考依据。

In order to study the melting characteristics of polymethylmethacrylate(PMMA) by CO2 laser irradiation, according to the heat conduction and energy conservation principle, the theoretical model of PMMA melting was established by low-power CO2 laser radiation. The laser parameters threshold of PMMA melting was calculated and the relationship between sample temperature change and laser parameters was analyzed. By the use of digital microscopy systems, SEM and XRD instruments, the melt morphology and tissue features of PMMA sample were discussed. The results show that laser power density 31.8 to 47.7 W/cm2 could make PMMA melt and does not occur thermal decomposition, and the experimental results is consistent with the theoretical calculations of laser melting threshold, which provides reference for CO2 laser melting mechanism and molding technology of PMMA.