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Title: Thin film initiation of cracks for fracture toughness measurements in epoxy resins: ARTICLE

Authors:
ORCiD logo [1];  [2];  [3];  [2]
  1. Army Research Laboratory, Aberdeen Proving Ground, Weapons and Materials Research Directorate, Maryland 21005, Department of Chemical & Biological Engineering, Drexel University, 3141 Chestnut Street Philadelphia Pennsylvania 19104
  2. Army Research Laboratory, Aberdeen Proving Ground, Weapons and Materials Research Directorate, Maryland 21005
  3. Department of Chemical & Biological Engineering, Drexel University, 3141 Chestnut Street Philadelphia Pennsylvania 19104
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1401013
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Applied Polymer Science
Additional Journal Information:
Journal Volume: 134; Journal Issue: 1; Related Information: CHORUS Timestamp: 2017-10-20 16:08:33; Journal ID: ISSN 0021-8995
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
United States
Language:
English

Citation Formats

McAninch, Ian M., La Scala, John J., Palmese, Giuseppe R., and Robinette, E. Jason. Thin film initiation of cracks for fracture toughness measurements in epoxy resins: ARTICLE. United States: N. p., 2016. Web. doi:10.1002/app.44364.
McAninch, Ian M., La Scala, John J., Palmese, Giuseppe R., & Robinette, E. Jason. Thin film initiation of cracks for fracture toughness measurements in epoxy resins: ARTICLE. United States. doi:10.1002/app.44364.
McAninch, Ian M., La Scala, John J., Palmese, Giuseppe R., and Robinette, E. Jason. 2016. "Thin film initiation of cracks for fracture toughness measurements in epoxy resins: ARTICLE". United States. doi:10.1002/app.44364.
@article{osti_1401013,
title = {Thin film initiation of cracks for fracture toughness measurements in epoxy resins: ARTICLE},
author = {McAninch, Ian M. and La Scala, John J. and Palmese, Giuseppe R. and Robinette, E. Jason},
abstractNote = {},
doi = {10.1002/app.44364},
journal = {Journal of Applied Polymer Science},
number = 1,
volume = 134,
place = {United States},
year = 2016,
month = 9
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/app.44364

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  • The improvement of the fracture toughness of epoxy resin has been tried to perform from the molecular level with an aim to improve the cryogenic properties of GFRP and/or the stability of superconducting magnets. The ceramic filler, which was formed by hydrolysis of alkoxide, was dispersed in the epoxy and cured. A coupling agent was also used to crosslink the filler and epoxy molecules. The positron annihilation lifetime was measured and the molecular state of the epoxies were evaluated. The thermal contraction and Vickers hardness were also measured. The thermal contraction and hardness were confirmed to reflect the molecular statemore » as evaluated by positron annihilation lifetime. The fracture toughness was also measured down to cryogenic temperatures. It was found that the improvement of the fracture toughness at cryogenic temperatures is possible.« less
  • Thermal expansion coefficient measurements of TACTIX-asterisk 695 epoxy resin have shown that although its glassy (less than Tg) thermal expansion coefficient is similar to those of conventional epoxy resins, it has a larger rubbery (greater than Tg) expansion coefficient than those seen for conventional resins of a similar glass transition temperature (Tg). This suggests that TACTIX-asterisk 695 resin may have a higher free-volume fraction in its glassy state than do conventional epoxy resins. The result of this is that less stress induced dilation is necessary for the polymer to reach a state at which it can yield. Thus the ductile-brittlemore » transition temperature is decreased and the resin is tough rather than brittle. Based on this hypothesis, it appears that a variety of materials may be quickly screened for toughness using a simple, common, thermomechanical analysis method. 18 references.« less
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  • A material configuration of central importance in micro electronics, optoelectronics, and thermal barrier coating technology is a thin film of one material deposited onto a substrate of a different material. Fabrication of such a structure inevitably gives rise to stress in the film due to lattice mismatch, differing coefficient of thermal expansion, chemical reactions, or other physical effects. Therefore, in general, the weakest link in this composite system often resides at the interface between the thin film and substrate. In order to make multi-layered electronic devices and structural composites with long-term reliability, the fracture behavior of the material interfaces mustmore » be known. This project is intended to address the problems associated with the deficiency of the existing methods, which show severe scatter in the existing data and the procedure dependence in thin film/coating evaluation methods, and offers an innovative testing procedure for the determination of interface fracture toughness applicable to thin coating materials in general.« less
  • The Series-Connected Hybrid Magnets under construction at the NHMFL use Cable-in-Conduct-Conductor (CICC) technology. The 4 K mechanical properties of the conduit are extremely important to the performance and reliability of the magnets. We have measured tensile and fracture toughness of two candidate conduit alloys (Haynes 242 and modified 316LN) in various metallurgical states, with emphasis on the final state of production. To assess the material in its final production state, non-standard specimens are removed directly from the round-corner rectangular conduit and tested after exposure to a simulated Nb{sub 3}Sn reaction heat treatment. Non-standard middle-tension (MT) fracture toughness specimens enable toughnessmore » evaluation of the base metal, welds and weld/base transitional region in the as-fabricated conduit with final dimensions not suitable for conventional fracture toughness specimens. Although fracture toughness tests of the thin walled conduit fail to meet ASTM test validity requirements they provide a qualitative evaluation and estimate of the fracture toughness of the conduit and the welds.« less