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Laser Ablation Resistance Behavior of Organosilicone Composite Coating on Various Substrates
Abstract
In modern combat, laser weapons are widely used due to their high precision, velocity and heat detriment. Hence, it is of great importance to fabricate protective coating on the surface of core components, i.e. gasoline tank and aerofoil. In this study, an organosilicone composite coating was prepared on steel and aluminum substrates through a simple spray process to resist laser ablation destroy. This composite coating consists of organic resin base and inorganic functional fillings, which were made up of glass powder with high melting point materials such as SiO2, BN and ZrO2 etc. Laser ablation resistance behavior was studied by means of oxyacetylene torch and laser irradiation. Results demonstrate that the coating presents excellent heat resistant behavior under 3000°C. Moreover, after impulse laser attack up to 105W/cm2, both substrates remain unhurt. As a result, this organosilicone composite coating can be used for anti-laser application in various fields.
... However, the reflection reduction of LST during laser irradiation should be mitigated for future applications [20]. For the energy consumption strategy, polymer materials such as organosilicons have been widely studied as anti-laser ablation materials owing to their good thermal consumption properties caused by their high pyrolysis endothermic enthalpies [21]. However, polymer materials have limited long-service applications. ...
During the fabrication of functional high-endothermic-enthalpy graphite/SiO2 composite coating, the oxidation and vaporization of raw materials have become serious issues in hyperthermal preparation environment. In this study, these issues were addressed through densification and modification of the feedstock powder. Then, the corresponding coating was prepared by optimized plasma-spraying parameters. By investigating the modified feedstock powder and the resulting splats and coatings by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy, we realized an optimized composite feedstock powder preparation process and an ideal coating structure. The compactness of the powder reached its optimum after treating at 1400 °C for 2 h. After heat treatment densification and Ni shell covering processes, the modified powder exhibited good oxidation resistance, vaporization resistance, and spreading performance during plasma spraying. Thus, a pure and dense composite coating was prepared. Positive laser resistance performance was observed during the initial laser ablation test, which proved that this modified graphite/SiO2 coating has good application potential in the laser protection field. Moreover, this study provides an experimental basis and a feasible method for difficult-to-spray composite coatings’ preparation, such as graphite/SiO2 composite.
... The outermost layer has a protective coating. According to thermomechanical properties, coating materials can be divided into reflection and ablation type [16][17][18][19]. By contrast, a new concept structure can be proposed based on the filled SPTC, which simultaneously considers laser resistance and load capability, as shown in Fig. 1(b). ...
A new function of filled sandwich panel with truss core, superior high-power laser resistance, is reported. When filled with carbon powder-reinforced silicone resin composite, which is an ablative material, the panel exhibits superior high-power laser resistance to monolithic plate with equal areal density. This paper revealed the detailed mechanisms and reproduced the process with numerical simulation. FIIR, SEM-EDS, and TG/DSC analyses on the virgin filler material and ablation residues are conducted to investigate the thermo-physicochemical process of the filler material during the laser ablation. Considering pyrolysis, oxidation, and phase change in the laser ablation process, a 3D numerical model is developed by using the finite element method. The temperature field and ablation morphology obtained from the numerical model agree with those from the experiment. The ablation evolution process, pyrolysis effect, and laser resistance mechanism of the filled sandwich panels with truss cores are evaluated based on the present model.
... Polymer matrix composites(PMCs) have been widely used in aerospace, marine and automobile industries during the past several decades resulting from their good engineering properties such as high specific strength and stiffness, lower density and so on [1,2]. However, the further utilization of PMCs in aerospace industry is threatened by the rapid development of laser weapons, due to the weak oxidation resistance, low operation temperature and poor antilaser ablation performance of the PMCs [3,4]. It has been authenticate that surface modification technologies enable to accomplish the feasibility and efficiency of protecting the PMCs substrates [5]. ...
Further utilization of polymer matrix composites (PMCs) in the aerospace industry is threatened by the development of laser weapons, resulting from weak oxidation resistance, low operation temperature and poor anti-laser ablation performance of the PMCs. Preparing an adhesive inorganic coating on the surface of components is an effective method to improve the laser irradiation resistance. Anti-laser ablation coatings composed of ZrO2 as pigment and sodium silicate as binder with different curing agents (including SiO2 and Na2SiF6) are fabricated on the PMCs substrate with brush painting. Influence of the different curing agents on anti-laser ablation of the coatings at the laser wavelength of 1064 nm is investigated. The rear surface temperature of substrate with coatings, containing SiO2 and Na2SiF6, decreases from 240 to 60 and 70 °C, respectively, when testing at 1000 W for 5 s. After irradiation test at 1000 W for 10 s, the coating with SiO2 as curing agent shows slight molten state on the surface, while the coating with Na2SiF6 is broke down, because coating containing SiO2 possesses more compact microstructure and fewer cracks than that with Na2SiF6.
In this study, laser ablation-resistant composite coating consisting of zirconium diboride (ZrB2) particulate and silicon carbide (SiC) whisker with zirconia (ZrO2)-sol binder was prepared to meet requirements of anti-laser ablation ability. Laser ablation behavior of as-prepared coating was investigated under varying laser powers. Results revealed that the highest back-surface temperature of coated aluminum substrate was only 150 °C when irradiated at a power density of 6.3 kW/cm² for 10 s, which is below the maximum allowable temperature of the aluminum alloy substrate (200 °C). After ablation for 10 s, the mass ablation rate of the composite coating was 4.45 mg/s. Apparently, the composite coating exhibited outstanding ablation resistance against high-intensity continuous laser irradiation. At initial stage of ablation, combination of self-healing effect of liquid ZrO2-SiO2 layer and volatilization of B2O3 provide effective joint protecting mechanism. With increasing ablation time, ZrO2 ceramic barrier layer, product of the pyrolysis of ZrO2 gel and ZrB2 filler, becomes progressively more important in maintaining excellent laser ablation resistance behavior, which is normally effective at around ablation pit.
In this work, an organic double-layer protective coating (ODC) was fabricated through a simple spray process on aluminum and steel. The coating is built as double-layer structure of heat resist base layer and reflective surface layer. Laser with power 103~104 Wcm-2 was set to ablate samples for 4s, while the temperature of panels’ back were being measured. Also, reflectivity of the coating was tested. Results demonstrated that reflectivity of ODC was up to 94%, and the panels were less apt to be ablated by laser radiation after coated, while the temperatures measured were substantially lower compared to blank panels with respect to the coating structure and composition.
Structure–property relations in polydimethylsiloxane (PDMS) containing segmented copolymers with model hard segments capable of forming hydrogen bonding, such as urea, N-methylurea and urethane have been investigated. High molecular weight silicone containing copolymers with these hard segments were prepared from PDMS oligomers with number average molecular weights ranging from 890 to 3750 g/mol. Due to major differences in the solubility parameters between PDMS and polar hard segments, all copolymers are expected to display good microphase separation. It was demonstrated that mechanical and thermal properties of these copolymers are directly linked to the strength of the hydrogen bonding in the hard segments. As expected, siloxane–urea copolymers displayed much higher tensile strengths when compared with siloxane–N-methylurea and siloxane–urethane copolymers with similar compositions.
The recognition of the potential for enhanced fracture toughness that can be derived from controlled, stress-activated tetragonal (t) to monoclinic (m) transformation in ZrO2-based ceramics ushered in a new era in the development of the mechanical properties of engineering ceramics and provided a major impetus for broader-ranging research into the toughening mechanisms available to enhance the fracture properties of brittle-matrix materials. ZrO2-based systems have remained a major focal point for research as developments in understanding of the crystallography of the t→m transformation have led to more-complete descriptions of the origins of transformation toughening and definition of the features required of a transformation-toughening system. In parallel, there have been significant advances in the design and control of microstructure required to optimize mechanical properties in materials developed commercially. This review concentrates on the science of the t→m transformation in ZrO2 and its application in the modeling of transformation-toughening behavior, while also summarizing the microstructural control needed to use the benefits in ZrO2-toughened ceramics.
Current developments of high power laser diode-pumped solid-state lasers such as disk rod laser, disk/slab laser, fiber laser and heat-capacity laser at home and abroad are investigated. Focusing on the problem of thermal effects in solid-state lasers which limits the increment of the output average power and degrades the output beam quality, the advantages and disadvantages of kinds of lasers are compared. Current techniques to decrease or compensate for the effects of the useless heat are summarized, and the probable techniques to reduce the laser's thermal effects are pointed out.
Based on their mechanical performance, carbon-carbon composites have been identified as attractive structural materials for aeropropulsion applications where temperatures may exceed 2000 degree C. However, these applications involve extended periods of operation in oxidizing environments. As a result, the development of reliable oxidation protection is crucial to utilizing the full potential of carbon-carbon composites. The present paper discusses the fundamentals of oxidation protection.
The Airborne Laser (ABL) is an airborne, megawatt-class laser system
with a state-of-the-art atmospheric compensation system to destroy enemy
ballistic missiles at long ranges. This system will provide both
deterrence and defense against the use of such weapons during conflicts.
This paper provides an overview of the ABL weapon system including: the
notional operational concept, the development approach and schedule, the
overall aircraft configuration, the technologies being incorporated in
the ABL, and the current program status.
Carbon–phenolic (C–Ph) composites are well fabricated to meet the requirements of thermal protection system by introducing ZrB2 particles. TG analysis demonstrates that the existence of ZrB2 particles could obviously aggrandize the char yield of phenolic, although it does not enhance the thermal stability of phenolic. What is more, the employed method of introducing ZrB2 could notably improve ablation resistance and insulation performance of C–Ph composites, which is mainly owing to the formation of ZrO2 and B2O3. As depicted in the microstructure, the ablation rate of matrix is evidently higher than carbon fibers in the C–Ph composites. However, the ablation rate of carbon fibers is identical to matrix in Z C–Ph composites.
Northrop Grumman Corporation has made significant progress in the development of compact, high power, continuous operation solid state lasers for military applications during the past six years. The Joint High Power Solid State Laser (JHPSSL) program is nearing completion of its third phase; its key objective is to demonstrate a 100kW solid state laser with excellent beam quality. Northrop's unique scalable architecture coherently combines modular 15kW lasers to produce power levels of 100kW and beyond with excellent beam quality and run times. This paper describes the JHPSSL program history, Northrop's high power solid state laser architecture and our demonstrated results.
A series of heat-insulating and ablating simulation tests were carried out using oxyacetylene flame to simulate the rocket engine exhaust flame, which was aiming at seeking for solution to the overheating and erosion- and ablation-induced failure of small scientific supersonic craft actuator caused by the engine exhaust flame. Thus the flowing fields of the rocket engine exhaust flame were analyzed by means of numerical simulation. The effectiveness of various organic resin coatings and ceramic coating in preventing the ablation of the actuator was investigated based on the simulation tests, rocket engine bench test, and field trial launch test. The temperature changes of the inner wall of the coated actuator during the field launch test were monitored using a data remote-sensing system and compared to that by numerical calculation. It was found that the flowing fields of the rocket engine exhaust flame could be readily analyzed using the numerical simulation method. The phenolic resin and silicone coatings had excellent ability to prevent the actuator from overheating and ablation. Specifically, the silicone coating of a thickness about 0.5 mm was able to keep the temperature on the inner wall of the actuator during the field launch test below 70 °C and hence could be suggested as the first choice to acquire satisfactory ablation and erosion protection of the actuator.
Moisture-cured polyurethane is one of the commercially important polymers, which is widely used in sealants, coatings, and reactive hot-melt adhesives. A series of moisture-cured polyurethane/polysiloxane (PUSR) copolymers were successfully prepared using a two-step solution polymerization procedure. Both amine-terminated polysiloxane (PDMS) and polyester diol were together used as mixed soft segments to react with 4,4′-diphenlymethane diisocyanate (MDI), and the alkoxysilane was used as end-capping agents. The effects of structure variation of building blocks such as the polyester diol structure and NCO/OH ratio on the properties and morphology of PUSR copolymers were studied. The tensile properties, dielectric behavior, thermal stability, surface, and water-repellency properties were investigated. The results showed that the properties and morphology of PUSR copolymers were greatly affected by the variations in molecular architecture. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Laser defense and countermeasure system for aircraft
- Milling
Science and technology of directed energy weapons
- Aps Study Group