Mechanical, thermal and ablative properties of zirconia, CNT modified carbon/phenolic composites

Srikanth, I.; Padmavathi, N.; Kumar, Suresh; Ghosal, Prasun; Kumar, Anil; Subrahmanyam, Ch.

doi:10.1016/j.compscitech.2013.03.005

Cited by 114 publications

(68 citation statements)

References 18 publications

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“…6) for all pure and reinforced RF show three prominent zones of weight loss. 42 As compared to other ablative composites, 9,26,38,40,43 OP-POSS/RF achieved relatively higher char yield (Table 2), which elevated to 59.2% aer the addition of 3 wt% of OP-POSS to pristine RF, which exhibited a char yield of 45.8%. 42 As compared to other ablative composites, 9,26,38,40,43 OP-POSS/RF achieved relatively higher char yield (Table 2), which elevated to 59.2% aer the addition of 3 wt% of OP-POSS to pristine RF, which exhibited a char yield of 45.8%.…”

Section: Thermogravimetric Analysismentioning

confidence: 89%

“…It is easily understood that with increasing the ller percentage, the rates diminished signicantly. 38 Moreover, unlike zirconia and CNT modied carbon-phenolic system, 38 it did not show accumulation of heat energy in the ablated surface, justifying the thermal barrier aspect and low thermal conductivity of the ablative material. 26 Detailed explanation of this phenomenon is done in further sections of this study.…”

Section: Ablation Rates and Back Face Temperaturementioning

confidence: 99%

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Hybrid caged nanostructure ablative composites of octaphenyl-POSS/RF as heat shields

Gupta

Kandasubramanian

2015

RSC Adv.

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A novel hybrid three dimensional thermosetting resin of resorcinol formaldehyde (RF) modified with different wt% of octaphenyl-polyhedral oligomeric silsesquioxane (OP-POSS) were successfully synthesized via facile in situ polymerization technique to form resol-type OP-POSS/RF ablative heat shielding material for thermal protection system (TPS). Ablation characteristics were investigated by exploring ablation rates in terms of dimensional change and mass loss that occurred after the samples were tested by a cheap yet effective oxyacetylene flame test. Linear and mass ablation rates of specimens ablated at 3000 C for 60 s at a heat flux of 8.5 MW m À2 reduced by 70% and 30%, respectively. The rates as low as 0.016 mm s À1 and 0.059 g s À1 were noted with an exceptionally low back face temperature, which remained below 150 C throughout the duration of the ablation test. The improved ablative properties of OP-POSS/RF can be attributed to the formation of an interconnected network of nanospheres, insulating the turbostratic carbonaceous char and ceramic char network of O x SiC y , which effectively blocks oxygen from attacking the matrix. X-Ray Diffraction pattern confirms the formation of insulative, carbonaceous char upon resin pyrolysis with peaks at 24 and 44 corresponding to (002) and (100). The FTIR signature showed peaks at 1501 (Si-CH]CH 2 ), 1375 (Si-CH 3 ), 1090, 555 (Si-O) and 794 (Si-C) cm À1 , which addressed the presence of the O x SiC y network. A maximum char yield of 59.2% and lowest density of 1.08 g cm À3 was achieved for RF with 3 wt% of OP-POSS. An improved char retention property of specimens were supported by post-test FESEM images of the surface ablated for 300 s, which revealed an interconnected broccoli-like pattern of char. Atomic Force Microscopy images were studied to understand the surface roughness of a specimen before and after the ablation test. Contact angle data provided evidence for formation of a hybrid protection layer on the nanocomposite's surface. The thermal model and energy balance equation was suggested for the exchange in heat energies occurring at the surface. This study justifies the competency of RF to replace conventional phenol formaldehyde (PF) and the use of OP-POSS/RF as an effective ablative composite employed as heat shields in re-entry vehicles.

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Section: Thermogravimetric Analysismentioning

confidence: 89%

Section: Ablation Rates and Back Face Temperaturementioning

confidence: 99%

Hybrid caged nanostructure ablative composites of octaphenyl-POSS/RF as heat shields

Gupta

Kandasubramanian

2015

RSC Adv.

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“…Srikanth et al studied the effect of zirconium oxide coating (thickness 700-900 nm) on the carbon fabric and found the reduction in thermal conductivity and the rear face temperature. Surface coating causes the reduction in the effective interfacial area between the fiber and the matrix which leads to a decrement in flexural modulus and interlaminar shear strength [54]. Thermally sprayed tungsten carbide and silicon coating are an effective method for effective thermal barrier shielding [55].…”

Section: Inorganic Nanocoating On Carbon Fibersmentioning

confidence: 99%

Hybrid Carbon-Carbon Ablative Composites for Thermal Protection in Aerospace

Sanoj

Kandasubramanian

2014

Journal of Composites

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Composite materials have been steadily substituting metals and alloys due to their better thermomechanical properties. The successful application of composite materials for high temperature zones in aerospace applications has resulted in extensive exploration of cost effective ablative materials. High temperature heat shielding to body, be it external or internal, has become essential in the space vehicles. The heat shielding primarily protects the substrate material from external kinetic heating and the internal insulation protects the subsystems and helps to keep coefficient of thermal expansion low. The external temperature due to kinetic heating may increase to about maximum of 500 ∘ C for hypersonic reentry space vehicles while the combustion chamber temperatures in case of rocket and missile engines range between 2000 ∘ C and 3000 ∘ C. Composite materials of which carbon-carbon composites or the carbon allotropes are the most preferred material for heat shielding applications due to their exceptional chemical and thermal resistance.

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“…Thus, a high compatibility in the system between synthetic fiber/filler with PF resin is achieved. It is reported that copper, graphite/CNTs/carbon fiber is a potential reinforcement for phenolic resins [12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Effect of Filler-Filler Interactions on Mechanical Properties of Phenol Formaldehyde Based Hybrid Composites

Pattanashetty¹,

Hemanth²

2017

IJET

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Abstract. Mechanical properties of phenol formaldehyde (PF) based hybrid composites reinforced with molybdenum disulphide (molykote; MC), copper (Cu), graphite (Gr) and antimony (Aty) particles in micron size, having different shape and aspect ratio, are studied. Incorporation of MC, Cu and Gr enhanced the hardness, compression and flexural properties of PF based hybrid composites. A slight decrease in density was observed in MC + Gr (A5) reinforced PF based hybrid composites, making these composites suitable in weight susceptible applications. The investigations showed that the control sample A1 without MC/Cu/Gr/antimony (control sample) exhibited poorer mechanical properties. Addition of Cu, MC and Gr to the control sample resulted in moderate improvement in the mechanical properties. However, hybridization of the control sample with Gr + Aty (A6) showed lower mechanical properties compared to that of composites filled with MC and Gr (A4 and A2) respectively. This decrease was ascribed to the tendency of non-uniform dispersion, deprived bonding of Aty particles as well as poor filler-matrix adhesion. When Aty was replaced with Gr + MC (Sample A5), filler-filler with matrix interaction appears to be increased, resulting in increased strength and modulus. The developed PF based hybrid composites have exhibited improved mechanical properties and these composites with detailed thermal and tribostudies may be recommended for railway braking applications.

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Mechanical, thermal and ablative properties of zirconia, CNT modified carbon/phenolic composites

Cited by 114 publications

References 18 publications

Hybrid caged nanostructure ablative composites of octaphenyl-POSS/RF as heat shields

Hybrid caged nanostructure ablative composites of octaphenyl-POSS/RF as heat shields

Hybrid Carbon-Carbon Ablative Composites for Thermal Protection in Aerospace

Effect of Filler-Filler Interactions on Mechanical Properties of Phenol Formaldehyde Based Hybrid Composites

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