Ultrasonic (C-scan) and microscopic evaluation of resin transfer molded epoxy composite plates

Date

2005-02-01

Author

KAŞ, Y. ONUR
Kaynak, Cevdet

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

157
views

0
downloads

One of the main problem in resin transfer molding (RTM) is the formation of microvoids decreasing the mechanical performance of the components. In this study, an ultrasonic inspection method (C-scan) was used to evaluate these microvoids. Composite sample plates were produced by a small laboratory size RTM machine injecting epoxy resin into a flat mold filled with woven carbon fiber layers. In C-scan analysis a certain value of energy loss (dB loss) was selected as the 'operator set level' and further dB losses were considered as 'defect' or 'microvoid'. C-scan inspection indicated that increasing injection pressure above 2 atm increases the number of microvoids leading to decreased mechanical properties. In the second part of this study, optical and electron microscopy were used to examine these microvoids and also failure mechanisms of the samples.

Subject Keywords

Organic Chemistry, Polymers and Plastics

URI

https://hdl.handle.net/11511/45890

Journal

POLYMER TESTING

DOI

https://doi.org/10.1016/j.polymertesting.2004.07.002

Collections

Department of Metallurgical and Materials Engineering, Article

Suggestions

OpenMETU
Core

DIPOLE-MOMENTS OF ISOTACTIC AND ATACTIC POLY(PROPYLENE OXIDE) SAMPLES KUCUKYAVUZ, Z; ALYURUK, K; AHMAD, AM (Elsevier BV, 1991-01-01) Dipole moments of poly(propylene oxide) (PPO) samples with different tacticities were determined from dielectric constant and refractive index increment measurements, which were performed on dilute toluene and isooctane solutions. In contrast to previous reports, both refractive index increments and the dipole moment ratios showed a marked dependence on the tacticities of the samples. The dipole moment ratios of isotactic samples were greater than unity and decreased with increasing sequence concentration...
MONOMER REACTIVITY RATIOS OF STYRENE-4-VINYLPYRIDINE COPOLYMERS AT LOW AND HIGH CONVERSIONS YILMAZ, E; KUCUKYAVUZ, Z (Elsevier BV, 1993-01-01) Monomer reactivity ratios in free-radical copolymerization of styrene and 4-vinylpyridine monomers at 80-degrees-C in toluene solution under reduced pressure were determined for low and high conversions. Finemann-Ross, Kelen-Tudos, extended Kelen-Tudos and Mayo-Lewis methods were used for this purpose. The most reliable method was found to be the extended Kelen-Tudos method. By the use of this method, for conversions below 20%, monomer reactivity values of 0.700 +/- 0.005 and 0.335 +/- 0.001 were calculated...
Mechanical properties of plasma surface-modified calcium carbonate-polypropylene composites Akovali, G; Akman, MA (Wiley, 1997-02-01) Calcium carbonate was surface-modified by plasma-polymerized acetylene and the effect of surface modification on the mechanical properties of calcium carbonate-polypropylene composites was investigated. Two different plasma polymerization conditions were selected and applied. Chemical structures of plasma-polymerized acetylene products were identified. Mechanical and thermal properties of the composites prepared were evaluated and the effects of surface modification on the extent of adhesion of filler to th...
ELECTROINITIATED POLYMERIZATION OF MALEIC-ANHYDRIDE BY DIRECT ELECTRON-TRANSFER Akbulut, Ural (Wiley, 1991-02-01) Controlled potential electrolysis was employed to accomplish homopolymerization of maleic anhydride, by direct electron transfer. The solvent used in the polymerization studies was acetonitrile-dimethylformamide mixture (1:1) with the supporting electrolyte tetrabutylammonium tetra fluoroborate. A brown paramagnetic polymer was obtained from the catholyte, upon electroreduction of monomer.
Flexibility improvement of short glass fiber reinforced epoxy by using a liquid elastomer Kaynak, Cevdet; Tincer, Teoman (Elsevier BV, 2003-03-17) In certain applications of fiber reinforced polymer composites flexibility is required. The aim of this study was to improve flexibility of short glass fiber reinforced epoxy composites by using a liquid elastomer. For this purpose, diglycidyl ether of bisphenol-A (DGEBA) based epoxy matrix was modified with hydroxyl terminated polybutadiene (HTPB). A silane coupling agent (SCA) was also used to improve the interfacial adhesion between glass fibers and epoxy matrix. During specimen preparation, hardener and...

Citation Formats

Y. O. KAŞ and C. Kaynak, “Ultrasonic (C-scan) and microscopic evaluation of resin transfer molded epoxy composite plates,” POLYMER TESTING, pp. 114–120, 2005, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/45890.