片状石墨增强树脂基复合材料的耐激光烧蚀性能研究

doi:10.3724/SP.J.1077.2012.00157

摘要/Abstract

摘要：

采用刷涂的方法制备了一种新型的片状石墨增强钡酚醛树脂基复合材料, 并采用重频激光辐照的方法, 对其耐烧蚀性能进行了研究. 研究结果表明: 片状石墨增强钡酚醛树脂基复合材料在平均功率密度为1700 J/cm²的重频激光辐照下的热烧蚀率为32.8 μg/J, 耐激光烧蚀性能明显高于碳纤维增强的钡酚醛树脂基复合材料和钡酚醛树脂; 片状石墨增强钡酚醛树脂基复合材料中的片状石墨呈近平行的层状分布方式, 在激光辐照过程中能对入射激光起到平面反射作用, 从而有效地降低激光辐照的能量沉积; 片状石墨的片型对复合材料的耐烧蚀性能有影响, φ0.5 mm的片状石墨增强的复合材料的耐激光烧蚀性能最好.

关键词: 片状石墨, 激光烧蚀, 重频激光, 热烧蚀率, 烧蚀机理

Abstract:

The carbon fiber reinforced phenolic resin composite is widely used as a thermal protection material because of its excellent thermal ablation. A novel flake graphite reinforced barium-phenolic resin composite was made by roller coating technology and its thermal ablation capability under long pulse laser irradiation was studied. The results show that the thermal ablation rate of the flake graphite reinforced barium-resin composite is 32.8 μg/J at 1700 W/cm² irradiation power density, which is much lower than that of the carbon fiber reinforced barium-resin composite or barium-phenolic resin obviously. The anti-ablative mechanism of the flake graphite reinforced barium- phenolic resin composite is investigated by the observation of its microstructure and the calculation of the laser energy coupling with the material. It is found that the flake graphite is arrayed homogeneous alignment as sandwich among the composite. When the laser radiation gets on the composite, the flake graphite plays as a mirror and reflects part of the laser, and then the laser radiation energy deposition on the composite is reduced. It is also found that the size of the flake graphite also affects the ablation capability. The composite with the flake graphite diameter of about 0.5 mm has the lowest thermal ablation rate.

Key words: flake graphite, laser ablation, millisecond pulse laser, thermal ablation rate, ablation mechanism

中图分类号:

TQ127

于庆春, 万红. 片状石墨增强树脂基复合材料的耐激光烧蚀性能研究[J]. 无机材料学报, 2012, 27(2): 157-161.

YU Qing-Chun, WAN Hong. Ablation Capability of Flake Graphite Reinforced Barium-phenolic Resin Composite under Long Pulse Laser Irradiation[J]. Journal of Inorganic Materials, 2012, 27(2): 157-161.

图/表 8

Table 1 Physical property of adopted material

Samples	Reinforcement	Reinforcement type	Mass fraction of reinforcement/%	Density/ (g·cm^-3)	Porosity /%
0^#	-	-	-	1.20	0.7
32^#	Flake graphite	F32	67.93	0.92	34.8
50^#	Flake graphite	F50	57.52	1.13	18.1
80^#	Flake graphite	F80	56.02	1.19	12.9
C_f^#	Carbon fiber	T300	62.05	1.34	7.5

图1 片状石墨增强钡酚醛树脂基复合材料热烧蚀率随激光平均功率密度的变化曲线

Fig. 1 Thermal ablation rate of three kinds of flake graphite reinforced barium-phenolic resin composites vs average power density

图2 钡酚醛树脂的热烧蚀率随平均功率变化曲线

Fig. 2 Thermal ablation rate of barium-phenolic resin vs average power density

图3 碳纤维增强钡酚醛树脂基复合材料热烧蚀率随重频激光平均功率密度的变化曲线

Fig. 3 Thermal ablation rates of carbon fiber reinforced barium- phenolic resin vs average power density

图4 复合材料烧蚀断面示意图片状石墨增强钡酚醛树脂基复合材料与碳纤维增强钡酚醛树脂基复合材料的基体相同, 但碳纤维增强钡酚醛树脂基复合材料的热烧蚀率是50#片状石墨增强钡酚醛树脂基复合材料热烧蚀率的2.2倍. 通过计算激光烧蚀过程中的能量转化, 分析了两种复合材料的烧蚀机理. 为了建立数学模型, 作以下三点假设: ①烧蚀坑为倒圆锥形; ②烧蚀坑内的复合材料全部烧蚀; ③烧蚀影响区内只有基体发生质量迁移, 增强体没有质量变化. 采用以下公式进行计算: ①烧蚀坑质量=圆锥烧蚀坑体积×复合材料密度; ②增强体烧蚀质量=烧蚀坑质量×增强体质量分数; ③基体烧蚀质量=烧蚀质量-增强体烧蚀质量; ④烧蚀热量=增强体烧蚀质量×增强体气化焓+基体烧蚀质量×基体烧蚀热; ⑤激光辐照能量=激光器输出功率×辐照时间=烧蚀热量+反射能量+辐射能量. 计算数据如表2所示, 从表中数据可以计算出: 50#片状石墨增强钡酚醛树脂基复合材料烧蚀所消耗的能量仅是碳纤维增强钡酚醛树脂基复合材料的52.6%; 50#片状石墨增强钡酚醛树脂基复合材料反射与辐射的能量是碳纤维增强钡酚醛树脂基复合材料的2.5倍. 在激光烧蚀过程中, 辐照区温度迅速上升, 当辐照区温度达到碳的气化温度后, 辐照表面温度相近, 由于辐射系数与温度的4次方成正比, 两种复合材料因极高温度产生热辐射而散失的能量也相近. 所以, 片状石墨增强的复合材料在激光烧蚀过程中对激光的反射能力比碳纤维增强的复合材料强, 这与片状石墨的反射性能和复合材料层状结构有关.

Fig. 4 Abridged general view of the ablation composites profile

Table 2 Comparison between flake graphite reinforced barium-phenolic resin and fiber carbon reinforced barium-phenolic resin with laser energy coupling

Composite	Average power energy /(W·cm^-2)	Laser energy/J	Mass ablation of composite /g *	Mass ablation of reinforcement/g	Ablation energy/J**	Reflected and radiation energy/J
50^#	1454.3	895.0	0.0273	0.0021	309.5	585.5
C_f^#	1332.4	820.0	0.0537	0.0037	588.3	231.7

图5 片状石墨与碳纤维反射率随波长的变化曲线

Fig. 5 Reflectance ratio of flake graphite and carbon fiber vs incident wavelength

图6 不同尺寸片状石墨增强钡酚醛树脂的切面结构

Fig. 6 Optical microscope images of the profile surfaces of flake graphite reinforced barium-phenolic resin

参考文献 14

[1]	Dudeja J P, Kalsey G S. Shipborne laser weapon system for defence against cruise missile. Defence Science Journal, 2000, 50(2): 231-240.
[2]	Lavan M. High energy laser systems for short rang defense. Acta Physica Polonica A, 2009, 115(6): 959-963.
[3]	马永龙, 许中胜, 王鹏. CO2舰载激光反导武器研究. 船舶电子工程, 2009, 29(11): 176-180.
[4]	任宁, 刘敬民, 秦凤英. 美国高能激光武器民展现状及远景规划. 红外与激光工程, 2008, 37: 375-378.
[5]	张俊华, 李锦文, 魏化震, 等. 高性能酚醛树脂基烧蚀复合材料的研究. 纤维复合材料, 2009, 15(1): 15-19.
[6]	穆景阳, 万红, 白书欣. 长脉冲激光辐照下环氧树脂的热烧蚀规律. 强激光与粒子束, 2008, 20(1): 36-39.
[7]	陈博, 万红, 穆景阳, 等. 重频激光作用下碳纤维/环氧树脂复合材料热损伤规律. 强激光与粒子束, 2008, 20(4): 547-551.
[8]	陶杰, 承涵, 陈照峰, 等. 聚碳硅烷复合涂层抗激光烧蚀研究. 宇航材料工艺, 2008(2): 39-42.
[9]	Liu H T, Cheng H F. Effects of the fiber surface characteristics on the interfacial microstructure and mechanical properties of the KD SiC fiber reinforced SiC matrix composites. Materials Science and Engineering A, 2009, 525(1): 121-127.
[10]	李雅娣, 吴平, 马喜梅, 等. 氧化锆涂层在激光防护上的应用. 表面技术, 2008, 37(3): 71-73.
[11]	张凌峰, 任凤章, 刘勇, 等. 激光冲击ZrO2陶瓷后微观分析. 材料科学与工艺, 2009, 17(6): 774-776.
[12]	Jyoti Prasad Gogoi, Nidhi S Bhattacharyyna. Sythesis and microwave characterization of expanded graphite/novolac phenolic resin composite for microwave absorber applications. Composites B, 2011(42): 1291-1297.
[13]	尹昌平. 共注射RTM制备承载/隔热/防热一体化复合材料. 长沙: 国防科学技术大学博士论文, 2009.
[14]	孙承纬,陆启生,范正修,等. 激光辐照效应. 北京, 国防工业出版社, 2002: 65-70.