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Laser ablation mechanism and performance of glass fiber-reinforced phenolic composites:An experimental study and dual-scale modelling

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Chinese Journal of Aeronautics 2024年第8期37卷 470-485页

作者： Ran BI Pengfei SHEN Longyu ZHU Zhengzheng MA Chuyang LUO Yongfeng LI Lijian PAN Shanghai Key Laboratory of Lightweight Composite Donghua UniversityShanghai 201620China Shanghai High Performance Fibers and Composites Center(Province-Ministry Joint) Center for Civil Aviation CompositesDonghua UniversityShanghai 201620China AVIC Composite Corporation Ltd Beijing 101300China

Both experimental and simulation approaches were employed to investigate the laser ablation mechanism and performances of Glass Fiber Reinforced Phenolic Composites(GFRP).During the ablation process,the difference in thermal conductivities of the glass fibers and the resin matrix as well as their discrepant physical and chemical reactions form a conical ablation *** formation of a residual carbon layer effectively mitigates the ablation rate in the thickness direction.A higher power density results in a faster ablation rate,while a longer irradiation time leads to a larger ablation pit *** account for the variation in thermal conductivity between the fiber and resin,a macro-mesoscale model was developed to differentiate the matrix from the fiber *** element analysis revealed that laser irradiation leads to phenolic decomposition,glass fiber melting vaporization,and residual carbon skeleton *** dual-scale model exhibits precise prediction capabilities concerning the laser ablation process of GFRP,and its accuracy is confirmed through the comparison of simulation and experimental results for the GFRP laser ablation *** model provides a feasible method for performance evaluation and lifetime prediction of GFRP subjected to continuous wave laser irradiation.

关键词： Polymer-matrix composites Continuous-wave laser Microstructural analysis ablation mechanism Finite element method

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Efficient fabrication of light Cf/SiHfBOC composites with excellent thermal shock resistance and ultra-high-temperature ablation up to 1800℃

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Journal of Advanced Ceramics 2023年第11期12卷 2062-2074页

作者： Yang Lyu Zhihong Han Guangdong Zhao Yuan Cheng Shanbao Zhou Xinghong Zhang Guiqing Chen Wenbo Han National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and StructuresHarbin Institute of TechnologyHarbin 150080China School of Chemistry and Materials Science Heilongjiang UniversityHarbin 150080China

In this paper,a high-yield Hf-modified SiHfBOC ceramic precursor was developed,and a high-pressure assisted impregnation pyrolysis method was proposed to achieve the preparation of 3D PyC–Cf/SiHfBOC *** high-pressure assisted impregnation method significantly improves impregnation filling effect of the precursor in and between fiber bundles compared to dozens of traditional impregnation *** undergoing just 9 precursor infiltration pyrolysis(PIP)cycles,the composites achieved relative density of approximately 90%and density of 1.64 g/cm^(3).The critical temperature difference of the 3D PyC–Cf/SiHfBOC composites after the shock of room temperature(RT)–1000℃is as high as 650℃,which is twice that of traditional ceramic materials,showing good thermal shock *** the effect of Hf modification,a dense HfO_(2)–SiO_(2)oxide layer(thickness of 93μm)was formed in situ on the surface of the 3D PyC–Cf/SiHfBOC composites,effectively preventing further erosion of the composite matrix by high-temperature oxidation *** in the ultra-high-temperature oxygen-containing environment at 1800℃,it still exhibits an excellent non-ablative result(with a linear ablation rate of 0.83×10^(−4)mm/s).This work not only enriches the basic research on lightweight ultra-high-temperature ceramic composites converted from Hf ceramic precursors,but also provides strong technical support for their applications in ultra-high-temperature non-ablative thermal protection materials for high-speed aircraft.

关键词： 3D PyC-C/SiHfBOC composites precursor infiltration pyrolysis(PIP)method thermal shock resistance ablation resistance ablation mechanism

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Plasma and nanoparticle shielding during pulsed laser ablation in liquids cause ablation efficiency decrease

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Opto-Electronic Advances 2021年第1期4卷 1-13页

作者： Sarah Dittrich Stephan Barcikowski Bilal Gökce Technical Chemistry I and Center of Nanointegration Duisburg Essen(CENIDE) University of Duisburg-EssenUniversitaetsstr.745141 EssenGermany

Understanding shielding cross-effects is a prerequisite for maximal power-specific nanosecond laser ablation in liquids(LAL).However,discrimination between cavitation bubble(CB),nanoparticle(NP),and shielding,e.g.,by the plasma or a transient vapor layer,is ***,CB imaging by shadowgraphy is performed to better understand the plasma and laser beam-NP interaction during *** comparing the fluence-dependent CB volume for ablations performed with 1 ns pulses with reports from the literature,we find larger energy-specific CB volumes for 7 *** increased CB for laser ablation with higher ns pulse durations could be a first explanation of the efficiency decrease reported for these laser systems having higher pulse ***,1 ns-LAL shows superior ablation ***,a CB cascade occurs when the focal plane is shifted into the *** effect is enhanced when NPs are present in the *** minute amounts of NPs trapped in a stationary layer decrease the laser energy significantly,even under liquid ***,this local concentration in the sticking film has so far not been *** presents an essential obstacle in high-yield LAL,shielding already the second laser pulse that arrives and presenting a source of satellite ***,measures to lower the NP concentration on the target must be investigated in the future.

关键词： shadowgraphy power-specific productivity flow dynamics ablation mechanism

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ablation Processes for HfC-Coated 2.5D Needle-Punched Composites Used for Aerospace Engines Under Hypersonic Flight Conditions

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Transactions of Nanjing University of Aeronautics and Astronautics 2024年第5期41卷 645-655页

作者： ZHANG Ziyi SHI Zhenyu NI Jing WANG Jilai ZHANG Chengpeng Key Laboratory of High Efficiency and Clean Mechanical Manufacture(Ministry of Education) Shandong UniversityJinan 250061P.R.China School of Mechanical Engineering Shandong UniversityJinan 250061P.R.China State Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Mechanical EngineeringHebei University of TechnologyTianjin 300130P.R.China School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310012P.R.China

The working environment of aerospace engines is extremely harsh with temperature exceeding 1700℃and accompanied by thermal coupling *** this condition,the materials employed in hypersonic aircraft undergo ablation issues,which can cause catastrophic *** to the excellent high-temperature stability and ablation resistance,HfC exhibits outstanding thermal expansion coefficient matching that of C/SiC composites.2.5D needle-punched C/SiC composites coated with HfC are prepared using a plasma spraying process,and a high-enthalpy arc-heated wind tunnel is employed to simulate the re-entry environment of aircraft at 8 Mach and an altitude of 32 *** plasma-sprayed HfC-coated 2.5D needle-punched C/SiC composites are subjected to long-term dynamic testing,and their properties are ***,after the thermal assessment ablation experiment,the composite retains its overall structure and profile;the total mass ablation rate is 0.07445 g/s,the average linear ablation rate in the thickness direction is-0.0675μm/s,and the average linear ablation rate in the length direction is 13.907μm/*** verify that plasma-sprayed HfC coating exhibits excellent anti-oxidation and ablation resistance ***,the microstructure and ablation mechanism of the C/SiC composites are *** is believed that this work will offer guideline for the development of thermal protection materials and the assessment of structural thermal performance.

关键词： 2.5D needle-punched C/SiC composites ablation mechanism arc-heated wind tunnel experiment high enthalpy flow

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