scholarly journals Ablation Behavior of Silicone Rubber-Benzoxazine-Based Composites for Ultra-High Temperature Applications

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1844 ◽  
Author(s):  
Gao ◽  
Li ◽  
Li ◽  
Liu
Keyword(s):  
Thermal Stability ◽  
Ablation Rate ◽  
Shielding Effect ◽  
Zro2 Content ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Rubber Composite ◽  
Back Face ◽  
Ceramic Compounds ◽  
Face Temperature

A novel type of silicon rubber composite with benzoxazine resins (BZs) and ZrO2 was prepared. The ablative response of the composites was investigated. The results showed that the composites with BZs had superior thermal stability and higher resides compared to the pristine composites. The linear ablation rate of the composites decreased significantly with the increase in ZrO2 content. The maximum back-face temperature of the burnt samples was no more than 100 °C for the obtained composites. Three major ablation processes were carried out simultaneously during the ablation processing. These mainly involved the carbonization of the composite, and the formation of ceramic compounds such as SiC and ZrC, as well as the shielding effect of the ablated layer, which subsequently enhanced the ablation resistance of the composites.

Ablation and mechanical investigation of heat vulcanizing silicone rubber (HVSR) composite containing carbon fibers

2017 ◽  
Vol 37 (5) ◽  
pp. 521-528 ◽  
Author(s):  
Yanhui Liu ◽  
Jingyu Su ◽  
Zhengshuai Yin ◽  
Yong Li ◽  
Ye Zhi ◽  
...  
Keyword(s):  
Carbon Fibers ◽  
Silicone Rubber ◽  
Ablation Rate ◽  
Shielding Effect ◽  
Characterization Methods ◽  
Ablation Mechanism ◽  
Back Face ◽  
The Matrix ◽  
The Impact ◽  
Face Temperature

Abstract In this study, heat vulcanizing silicone rubber (HVSR) composites were prepared and the impact of the addition of carbon fibers (CFs) on the mechanical and ablation properties of the composite was demonstrated. It was found that with increasing content of CFs, the tensile property and the hardness of the composite increased significantly. The back-face temperature, the ablation rate and the ablation mechanism of the composite were discussed based on the data derived from several characterization methods, including oxygen-acetylene ablation device, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Along with the increasing of the content of CFs, the mass and linear ablation rates both decreased, but the back-face temperature increased. The interaction between ablation layer and the composite became intense due to the addition of the CFs, which led to the difficult peel-off of the ablation layer. Four layers can be formed after the oxygen-acetylene ablation of the composite including the surface layer, the carbonization layer, the pyrolysis layer and the matrix layer. The ablation mechanism was also proposed. It mainly involves the carbonization of the composite, the ceramization of SiC and the shielding effect of the ablated layer.

scholarly journals Preparation and Properties of C/SiC Composites Reinforced by High Thermal Conductivity Graphite Films

2020 ◽  
Author(s):  
Jiajia Zhao ◽  
Rong Cai ◽  
zhaokun Ma ◽  
Kaixuan Zhang ◽  
Hengliang Liang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mass Loss Rate ◽  
Ceramic Matrix Composites ◽  
Ablation Rate ◽  
High Thermal Conductivity ◽  
Matrix Composites ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Graphite Film ◽  
Sic Composites

Abstract Ablation resistance as one important factor affecting the service life of SiC ceramic matrix composites that is highly valued in aerospace science and technology. In this study, high thermal conductivity (HTC) graphite films and carbon fibers reinforced C/SiC composites simultaneously, fabricating by precursor infiltration and pyrolysis (PIP) technology, to improve the ablation resistance of C/SiC composites. Three C/SiC composites were prepared from different quantity ratios of 2D fiber cloth to HTC graphite film with values of 1:0, 1:1, and 1:10. The microstructure, mechanical properties, thermal conductivity and ablation performance of C/SiC composites after plasma ablation test at 1500 °C for 600 s were investigated. The results showed that with the increase of graphite films’ contents, the thermal conductivity of composites was increased from 9.78 W/(m·K) to 333.34 W/(m·K). Additionally, the mass loss rate reduced from 1.18 to 0.74 mg/s and the linear ablation rate reduced from 0.64 to 0.18 mm/s, indicating that the addition of graphite films could effectively improve the ablation resistance of C/SiC composites.

EPDM-based heat-shielding materials modified by hybrid elastomers of silicone or polyphosphazene

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1112-1121 ◽  
Author(s):  
Shaojun Wu ◽  
Shuangkun Zhang ◽  
Raheel Akram ◽  
Abbas Yasir ◽  
Bowen Wang ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
State Of The Art ◽  
Ablation Rate ◽  
Solid Rocket Motor ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Insulation Systems ◽  
Solid Rocket ◽  
Heat Shielding ◽  
Methyl Phenyl

The erosion resistances of ethylene propylene diene monomer (EPDM) insulations are often inadequate for advanced solid rocket motor (SRM) applications. EPDM modification by blending secondary matrixes is a feasible approach to improve the ablative properties of EPDM insulations. The addition of flexible inorganic hybrid rubbers as a secondary matrix, such as silicones and polyphosphazenes, may impart EPDM insulations with better ablative performance. The blends of EPDM/hybrid rubbers represent the state-of-the-art heat-shielding materials for SRM. In the present work, methyl-phenyl silicone/EPDM and poly(diaryloxyphosphazene)/EPDM insulation systems with various blending ratios of secondary matrixes have been prepared. The ablative properties of the insulations were examined by oxy-acetylene ablation tests, and the results showed that these properties could be enhanced accordingly by blending with hybrid rubbers under appropriate proportions. The unique charred layers resulting from the hybrid rubbers contributed to their excellent ablation properties. For example, the silicone/EPDM insulations exhibited a more significant improvement of ablation resistance properties. With a 1:1 blending ratio of silicone/EPDM, the linear ablation rate was 0.06 mm s−1 after 20 s of oxy-acetylene ablation. The enhancement in the ablative resistance was attributed to the charred layers with bunches of embedded compact microtubes with a length of 2–3 mm, which consisted of silicon carbide, silicon dioxide, and Si–O–C ceramics.

scholarly journals Experimental Study of The Insulating Effectiveness of Silicone Rubber Composites by Oxyacetylene Ablation Testing

2020 ◽  
pp. 1-11
Author(s):  
Artem Andrianov ◽  
Jungpyo Lee ◽  
Gabriela Possa ◽  
Hiterson de Oliveira Silva
Keyword(s):  
Carbon Fibers ◽  
Silicone Rubber ◽  
Ablation Rate ◽  
Low Thrust ◽  
Flame Direction ◽  
Hybrid Propulsion ◽  
Silica Fibers ◽  
Back Face ◽  
Glass Carbon ◽  
Face Temperature

The objective of this study was to characterize the thermal insulation efficiency of the silicone rubber reinforced composites by oxyacetylene torch. These composites reinforced by glass, carbon, ceramics and silica fibers were intended to be used as ablators in a low-thrust hybrid propulsion motor. The back-face temperature measurements were used as a criterion for insulation efficiency of the specimens, whose frontal face is subjected to the oxyacetylene flame for 40 s. The paper includes the results of the ablation rate measurements and the influence of orientation of glass and carbon fibers relatively to the flame direction on the back-face temperature of the specimens.

scholarly journals Understanding the Role of Carbon Fiber Skeletons in Silicone Rubber-Based Ablative Composites

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 268
Author(s):  
Yuan Ji ◽  
Shida Han ◽  
Zhiheng Chen ◽  
Hong Wu ◽  
Shaoyun Guo ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Ablation Rate ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Linear Ablation ◽  
Dense Ceramic ◽  
Back Face ◽  
Solid Rocket ◽  
Ceramic Fillers

At present, silicone rubber-based ablative composites are usually enhanced by carbon fibers (CFs) to protect the case of solid rocket motors (SRMs). However, the effect of the CFs’ length on the microstructure and ablation properties of the silicone rubber-based ablative composites has been ignored. In this work, different lengths of CFs were introduced into silicone rubber-based ablative composites to explore the effect of fiber length, and ceramic layers of various morphologies were constructed after ablation. It was found that a complete and continuous skeleton in ceramic layers was formed by CFs over 3 mm in length. In addition, the oxyacetylene ablation results showed that the linear ablation rate declined from 0.233 to 0.089 mm/s, and the maximum back-face temperature decreased from 117.7 to 107.9 °C as the length of the CFs increased from 0.5 to 3 mm. This can be attributed to the fact that successive skeletons concatenated and consolidated the ceramic fillers as well as residues to form an integrated, robust, and dense ceramic layer.

Preparation of Cf/HfC Composite by Reactive MeltInfiltration Using Hf-Based Alloy

2015 ◽  
Vol 816 ◽  
pp. 126-132 ◽  
Author(s):  
Zhen Huan Yang ◽  
Hong Zhang ◽  
Yi Cong Ye
Keyword(s):  
Phase Diagram ◽  
Melting Point ◽  
Fracture Behavior ◽  
Ablation Rate ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Melt Infiltration ◽  
Oxide Barrier ◽  
Reactive Melt Infiltration ◽  
Reactive Melt

A HfZrSiTa alloy of low melting point was designed by phase diagram calculation and smelted. The Cf/HfC composite was then prepared by reactive melt infiltration at relative low temperature. The open porosity of specimen was 8.45%. By SEM, XRD and EDS, it was found that the melt infiltration microstructure mainly consists of HfC, ZrC, Hf2Si, Zr2Si phases and a small amount of Hf, Zr phases. The as-received Cf/HfC composite, with the flexural strength of 165 MPa, displayed a typical brittle fracture behavior. Ablation properties of the Cf/HfC composite were tested by an oxyacetylene flame. The linear ablation rate was 0.03 mm/s. An oxide barrier layer was formed on the ablation surface and the ablation resistance of the composite has been largely improved.

scholarly journals Characteristics of ZrC Barrier Coating on SiC-Coated Carbon/Carbon Composite Developed by Thermal Spray Process

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 747 ◽  
Author(s):  
Bo Kang ◽  
Ho Kim ◽  
Phil Oh ◽  
Jung Lee ◽  
Hyung Lee ◽  
...  
Keyword(s):  
Ablation Rate ◽  
Carbon Composite ◽  
Vacuum Plasma Spray ◽  
Thermal Spray Process ◽  
Spray Process ◽  
Barrier Coating ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Zrc Coating ◽  
Coated Carbon

A thick ZrC layer was successfully coated on top of a SiC buffer layer on carbon/carbon (C/C) composites by vacuum plasma spray (VPS) technology to improve the ablation resistance of the C/C composites. An optimal ZrC coating condition was determined by controlling the discharge current. The ZrC layers were more than 70 µm thick and were rapidly coated under all spraying conditions. The ablation resistance and the oxidation resistance of the coated layer were evaluated in supersonic flames at a temperature exceeding 2000 °C. The mass and linear ablation rate of the ZrC-coated C/C composites increased by 2.7% and 0.4%, respectively. During flame exposure, no recession was observed in the C/C composite. It was demonstrated that the ZrC coating layer can fully protect the C/C composites from oxidation and ablation.

Thermal Response and Ablation Research of EPDM Thermal Protection Material in Ramjet

2015 ◽  
Vol 1092-1093 ◽  
pp. 534-538
Author(s):  
Xiong Chen ◽  
Hai Feng Xue ◽  
Hua Liang
Keyword(s):  
Heat Transfer ◽  
Heat Load ◽  
Thermal Protection ◽  
Thermal Response ◽  
Transfer Model ◽  
Back Face ◽  
Ground Test ◽  
Simulation Results ◽  
Face Temperature ◽  
Scanning Electron

Thermal protection materials are required to preserve the metal components of motor that suffer severe heat load. The research on thermal response of insulation of ramjet combustion chamber was carried out by the ground test and numerical simulation. During the working time of the ramjet, the back-face temperature of the thermal protection material was measured. The scanning electron microscope of samples was investigated. The calculation of thermo-chemical flow was solved by the CFD software FLUENT to provide the heat load boundary for simulation of heat transfer of EPDM insulation. The heat transfer model was solved by the FEA software ANSYS. Comparison of the temperature profile at the ablating surface between calculation and measurement shows the two results agree with each other. The simulation results can provide the temperature rising trend of insulation in a certain extent.

scholarly journals Effect of Organo Montmorillonite Nanoclay on Mechanical Properties Thermal Stability and Ablative Rate of Carbon fiber Polybenzoxazine Resin Composites

2021 ◽  
Vol 71 (5) ◽  
pp. 682-690
Author(s):  
Golla Rama Rao ◽  
Ivaturi Srikanth ◽  
K. Laxma Reddy
Keyword(s):  
Thermal Stability ◽  
Carbon Fiber ◽  
Ablation Rate ◽  
Constant Heat Flux ◽  
Type I ◽  
Type Ii ◽  
Weight Percentage ◽  
Mechanical Erosion ◽  
Interlaminar Shear ◽  
Rate Behaviour

Organo-Montmorillonite (o-MMT) nanoclay added polybenzoxazine resin (type I composites) were prepared with varying amounts of clay (0, 1, 2, 4 and 6 wt %). Clay dispersion, changes in curing behaviour and thermal stability were assessed in type I composites. Findings from these studies of type I composites were used to understand thermal stability, mechanical, and mass ablation rate behaviour of nanoclay added carbon fiber reinforced polybenzoxazine composites (type II). Interlaminar shear strength and flexural strength of type II composites increase by 25% and 27%, respectively at 2 wt% addition of clay. An oxy-acetylene torch test with a constant heat flux of 125 w/cm2 was used to investigate mass ablation rate of type II composites. The ablation rate has increased as the weight percentage of clay has increased. This is contradicting to type I composites with up to 6 wt% clay and type II composites with up to 4 wt% clay, which have improved thermal stability. The microstructure of the ablated composites was examined using scanning electron microscopy. Increased ablation rates are due to the reaction of charred matrix with nanoclay, which exposes bare fibers to the ablation front, resulting in higher mechanical erosion losses.

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