Master Bond EP21TCHT-1 is a two component, thixotropic paste formulated for bonding and sealing applications. This system has been used in various applications involving different substrates, service conditions and requirements. Multiple published research articles from University of Florida, Princeton University and NASA, among others make reference to the use of Master Bond EP21TCHT-1. This heat resistant epoxy is serviceable over the temperature range of 4K to +400°F and maintains its properties under cryogenic conditions. This room temperature curing compound is thermally conductive and electrically insulative. EP21TCHT-1 passes NASA low outgassing testing and is therefore recommended for use in vacuum environments. Below is a summary of the many ways EP21TCHT-1 has been effectively used in research labs and commercial applications.
| Application | Substrates | Conditions/Requirements |
| Magnet bonding and potting1 | Sm-Co magnets | Low outgassing, low CTE, high strength, and ability to be used at cryogenic temperatures. |
| Sister-block bonding for a telescope2 | SiC | Low outgassing, low CTE, high strength, and ability to be used at cryogenic temperatures. |
| Mounting gratings for a telescope3 | Silicon; titanium alloy; invar | Operational temperature of 200K |
| Laser packaging assembly4 | Glass; Si wafers with gold metallization | 4K to 400°F service temperature range |
| Wire bonding in micro sensor packaging5 | Gold; TO-39 header | |
| Mirror coating6 | Mirror | NASA low outgassing; used in environments of 10-9 torr |
| Teflon wire coated with epoxy; used to secure the wire tie downs to the structure7 | Teflon*1 | NASA low outgassing |
| Sealing magnetic field coils8 | Wrapped fiberglass braid | Epoxy is intended to eliminate vacuum leaks |
| Ionizer coating9 | Ceramic; radioactive silver foil | Low outgassing |
| Bonding heat dissipation plate to housing wall of laser emitter module10 | Ceramic | Electrically insulative, thermally conductive |
| Solar cell package bonding and sealing11 | Solar cell; aluminum | Thermal conductivity |
| Sealing a probe12 | Stainless steel | NASA low outgassing |
| Bonding metal mounting blocks to lenses13 | Fused silica; metal; zinc selenide; calcium fluoride; sapphire | Provided really good bond strength, and broke the substrates in some bond strength tests |
| Spectrograph camera assembly: Injected between spider and bushing14 | Optical Lens, ICs, ultem, metals | Flow; gap filling; precise alignment |
| Bonding heat sink components15 | Copper, aluminum | NASA low outgassing |
| Sister block bonding for space based gravitational wave detectors16 | SiC | Dimensional stability, bond strength |
*1 - Teflon needs to be chemically etched for epoxies to adhere to it.
EP21TCHT-1 Application Highlight
University of Florida, wrote a study titled Stability Of Materials For Use In Space-Based Interferometric Missions.2 Among the topics discussed in this paper was the use of hydroxide bonding for the assembly of instrumentation for space based missions. A prototype telescope support structure for the Laser Interferometer Space Antenna (LISA) mission was constructed. After fabrication of the telescope was completed, it was found that a hydroxide bonded strut was tilted. A small amount of force was able to dislodge the strut following exposure to -70°C. In attempt to provide extra strength to the multiple struts in the structure, they tried sister-block bonding using an epoxy adhesive in conjunction with hydroxide bonding to adhere SiC to SiC for strut bonding.
After researching several different epoxy compounds, Master Bond EP21TCHT-1 was selected for the sister-block bonding application. It offered a combination of advantageous properties including:
- Low outgassing
- Fast room temperature cure
- Low CTE
- High strength
- Cryogenic serviceability
Master Bond EP21TCHT-1 was cured for 2 days at room temperature and applied without any surface preparation. Shear strength tests showed significant improvement in results over hydroxide bonding and demonstrated the suitability of using EP21TCHT-1 for sister-block bonding.2
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Sources
1Wood, Gary J., Andrew Buffalino, Ezekiel Holliday, Barry Penswick, David Gedeon. Free-Piston Stirling Power Conversion Unit For Fission Surface Power, Phase I Final Report. Prepared under Contract NNC08CA65C for National Aeronautics and Space Administration. July 2010. August 25, 2016. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100031133.pdf
2 Preston, Alix. Stability Of Materials For Use In Space-Based Interferometric Missions. N.P. August 2010. August 2016. http://ufdcimages.uflib.ufl.edu/UF/E0/04/14/95/00001/preston_a.pdf
3 Van Amerongen, Aaldert, Hélène Krol, Catherine Grèzes-Besset, R.W.M. Hoogeveen, Ianjit Bhatti, Dan Lobb, Bram Hardenbol,R.W.M. Hoogeveen. State Of The Art In Silicon Immersed Gratings For Space. ResearchGate. May 19, 2015. July 5, 2016. https://www.researchgate.net/publication/268294938_State_of_the_art_in_s...
4 Mercado, Emmanuel. Low-Temperature Characterization Of A 1.55-µm Multiple-Quantum-Well Laser Down To 10 K. N.P. May 2013. July 2016. https://repository.unm.edu/bitstream/handle/1928/23201/REVISED%20FINAL.p...
5 Shu, Huihua. Applications Of Poly (3-Hexylthiophene) Thin Film As A Hydrazine-Sensitive Chemiresistor. N.P. Dec 15, 2006. July 2016. https://etd.auburn.edu/bitstream/handle/10415/570/SHU_HUIHUA_8.pdf?seque...
6 Gaunt, Robert, Scott Roberts, Andre Anthony. 2003. “Mechanism For Transmitting Movement In Up To Six Degrees-Of-Freedom.” U.S. Patent 6,543,740 B2, filed September 4, 2001 and issued April 8, 2003.
https://www.google.com/patents/US20030047660. July 2016
7 Owens, Jeremy J. Captain, USAF. Final Assembly, Testing And Processing Of The Rigidizable Inflatable Get-Away-Special Experiment (Rigex) For Spaceflight Qualification. Department Of The Air Force, Air University, Air Force Institute Of Technology, Wright-Patterson Air Force Base, Ohio. Approved For Public Release; Distribution Unlimited. September 2007. July 2016.
https://apps.dtic.mil/sti/tr/pdf/ADA522020.pdf. Accessed September 2023.
8 Hsu, Scott C. Experimental Study of Ion Heating and Acceleration During Magnetic Reconnection. N.P. June 2000. July 2016. http://www.osti.gov/scitech/servlets/purl/750977
9 Denson, Stephen Charles. Improving the Sensitivity and Resolution of Miniature Ion Mobility Spectrometers with a Capacitive Trans Impedance Amplifier. The University of Arizona. 2005. July 5, 2016. http://hdl.handle.net/10150/195646.
10 Liu, Daming, Edmund L. Wolak, Serge Cutillas, 2014. “High Reliability Laser Emitter Modules.” U.S. Patent 8,644,357 B2, filed January 11, 2011 and issued February 4, 2014. http://www.google.ci/patents/US8644357.
11 Zhang, Hongxi, Weiping Lin, Michiharu Yamamoto, 2015. “Packaged luminescent solar concentrator panel for providing high efficiency low cost solar harvesting” U.S. Patent 20150194555 A1, filed Dec 30, 2014 and issued July 9, 2015. https://www.google.com/patents/WO2015103152A1
12 Carter,Troy Alan. Experimental studies of fluctuations in a reconnecting current sheet. Princeton University. November 2001.
https://www.proquest.com/openview/333a0f0b90580f74843d930a9c487468/1?pq-origsite=gscholar&cbl=18750&diss=y. Accessed September 2023.
13 Echols, Chris. KIRMOS Test Report 06.00 Adhesive Qualification Tests. UCLA. December 4, 2003.
http://instrumentation.tamu.edu/files/SPIE/Tuttle_VIRUS_results.pdf. Accessed September 2018.
14 Tuttle, Sarah E., Richard D. Allen, Taylor S. Chonis, Mark E. Cornell, Darren L. DePoy, Gary J. Hill, Hanshin Lee, Jennifer L. Marshall, Travis Prochaska, Marc D. Rafal, Richard D. Savage, Brian L. Vattiata. Initial Results from VIRUS Production Spectrographs. University of Texas at Austin, Texas A&M University.
https://www.spiedigitallibrary.org/conference-proceedings-of-spie/8446/1/Initial-results-from-VIRUS-production-spectrographs/10.1117/12.925478.short?SSO=1. Accessed September 2023.
15 Tischler, Tobias. CBM Micro Vertex Detector mechanical integration and cooling. Goethe University Frankfurt. 2011. https://indico.cern.ch/event/144152/contributions/1379153/attachments/13...
16 Sanjuan, J., D. Korytov, G. Mueller, R. Spannagel, C. Braxmaier et al. AIP Review of Scientific Note: Silicon carbide telescope dimensional stability for space-based gravitational wave detectors Instruments. American Institute of Physics. 2012. http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140009255.pdf