基于飞秒激光表面修饰的石英玻璃润湿性分析

Analysis on the wettability of fused silica glass surface modified by femtosecond Laser

采用飞秒激光高速扫描的方法对熔石英表面进行多级微纳结构制备,其中一级结构为周期性微纳条纹结构,二级结构为蚀刻沟槽,三级结构为沟槽交叉形成的阵列结构.通过数值计算分析了飞秒激光高速扫描下熔石英的烧蚀阈值,揭示了高速飞秒激光诱导熔石英表面微纳结构的机理.对修饰后的熔石英微观形貌观察和润湿性试验表明,当飞秒激光重复频率1 MHz,扫描速度1000 mm/s,55%峰值功率时,熔石英表面沟槽间距为30μm的正交阵列具有最优的润湿性.与未处理的熔石英相比,Bi2O3-50%B2O3(质量分数,%)钎料在修饰后熔石英表面的润湿角降低了8°,有效改善了熔石英玻璃的钎焊能力.

A femtosecond laser high-speed scanning method is used to prepare hierarchical micro-nano structures on the surface of fused silica.One-scale is periodic micro-nano structure,two-scale is the ablation groove and triple-scale is the gridding structure comprised by bi-direction grooves.The mechanism of micro-nano structure fabricated by femtosecond laser scanning at high speed was revealed through numerical calculations.The wettability test shows that micro-nano structure with the period of 400~500nm which obtained under 1 MHz,1000 mm/s,55%peak power and 30μm the orthogonal groove spacing has the best wettability.The contact angle of Bi2O3-50%B2O3 solder can be reduced by 8°than that of unmodified fused silica which is beneficial to reduce the residual stress of the brazed joint.