毫秒/纳秒激光致碳纤维环氧树脂损伤形貌研究

为了研究碳纤维环氧树脂在不同脉宽激光辐照下的损伤形貌，采用全自动变焦测量技术进行了实验验证，测量了碳纤维环氧树脂在毫秒/纳秒脉冲激光辐照下，损伤面积、损伤深度以及损伤形貌随激光能量密度的变化。结果表明，在毫秒脉冲激光作用下，材料损伤区域中心会产生一定的温度积累，损伤区域有一定的热效应，出现熔融、热解等现象，当激光能量密度为20.5J/cm2时，材料的损伤深度达到了47.3μm，材料表面析出的碳化物的高度为157.1μm，损伤深度以及表面碳化物的高度都随着能量密度的增大而增大；在纳秒激光作用下，光斑周围有明显的热反应区域，当能量密度大于47.3J/cm2时，表面的热反应区尤为明显，损伤面积随激光能量密度的增大明显增大，由于作用时间较短，损伤主要为表层损伤；树脂热解的气体向外膨胀，导致纤维结构断裂。研究结果为激光对碳纤维环氧树脂的损伤效果提供了实验依据。

Research of damage morphology of carbon fiber epoxy resin irradiated by millisecond/nanosecond pulsed laser

In order to study the damage morphology of carbon fiber epoxy resin irradiated by laser with different pulse widths, automatic zoom measurement technique was used to test the changes of the damage area, damage depth and damage morphology of carbon fiber epoxy resin with laser energy density. The results show that, under the action of millisecond pulsed laser, a certain temperature accumulation will be produced in the center of the damage region of the composite material. The damage region has some thermal effect, melting, pyrolysis and so on. When the laser energy density is 20.5J/cm2, the damage depth of the material reaches 47.3μm, and the height of carbide precipitated on the surface of the material is 157.1μm. The depth of damage and the height of surface carbonization increase with the increase of energy density. There are obvious thermal reaction regions around the spot under the action of nanosecond laser. When the energy density is greater than 47.3J/cm2, the thermal reaction area of the surface is particularly obvious. And the damage area increases obviously with the increase of laser energy density. Because of the short time, the damage is mainly surface damage and the outward pyrolysis gas expedition results in the fracture of fiber structure. The research results provide an experimental basis for laser damage effect on carbon fiber epoxy resin.