I am trying to fabricate a resistive heater from Nichrome foil on an Alumina substrate, that will give a very high heat flux around 500 w/cm^2, which may cause delamination of the foil or bad adhesion.
so, could you suggest an adhesive that can do the job ?
You may want to check signalled RG discussions: https://www.researchgate.net/post/How_can_I_connect_metal_wire_with_thin_metal_film_deposited_on_a_alumina_substrate https://www.researchgate.net/post/What_are_compatible_metallization_schemes_for_both_wire_bonding_and_soldering_available_on_Al2O3_ceramics_Can_you_propose_a_supplier
Dear Dr. Ibrahim O. Elhagali,
You can use Master Bond EP 17HT LO, one component epoxy adhesive, with high temperature resistance for bonding of Nichrome (stainless steel) foil to Alumina (the temperature resistance to 340 oC). The Nichrome foil should be degreased using a mixture of organic solvents: technical gasoline, acetone and n-butyl alcohol in a 4 : 0.5 : 0.5 by volume ratio. After degreasing with the solvent mixture, the stainless steel surface is rinsed with acetone p.a. The surface of the alumina can be before bonding coated with fine silver layer (electroless plating) reduced from AgNO3 water solution to the Alumina surface. The preparation of AgNO3 solution for electroless plating with silver can be sent to you if necessary.
Best regards,
Igor Novák
V R Arun Prakash thanks so much for your suggestion.
I see Araldite has very low thermal conductivity, could suggest another one?
Dr Carlos Araújo Queiroz thank you.
This tends out to be an adhesive between two metals; a thin film Kanthal alloy and a copper wire.
Thank you Dr Igor Novak , I have sent an email to the company to get the physical properties, specially the thermal conductivity.
could you please send me more technical data, in case you have some?
Dear Dr. Ibrahim O. Elhagali,
I am sending you Master Bond EP17HT-LO Product information (technical data) (https://www.masterbond.com/tds/ep17ht-lo) :
Master Bond EP17HT-LO is an extraordinary one component, heat cured epoxy system for bonding, sealing, coating and encapsulating. It features excellent physical properties, a superb electrical insulation profile and chemical resistance even with heat exposure to 650°F. Its glass transition temperature (Tg) is 225°C. This system is also distinctive in that it has very low exotherm upon curing and can be used in castings and encapsulations well beyond ½ inch in thickness. The minimum curing temperature for EP17HT-LO is 300°F with faster cures attainable at higher temperatures. Please refer to the curing section for additional details.
EP17HT-LO is 100% reactive and contains no solvents or diluents. EP17HT-LO bonds well to similar as well as dissimilar substrates such as metal, ceramics, plastics and composites. It resists many chemicals such as acids, bases, salts, fuels, oils and many solvents. Shrinkage upon cure is minimal. It is serviceable from -80°F to +650°F. This system is tan in color. EP17HT-LO retains its exceptional electrical insulation properties, even at higher temperatures. It should be noted, in order to obtain the optimum properties, a post cure of 2-12 hours at 350°F is recommended. As mentioned above, EP17HT-LO meets NASA low outgassing specifications. It is widely used in a variety of applications in the aerospace, oil and chemical processing, optical, optoelectronic and specialty OEM industries.
Product Advantages
- Single component system; no mixing prior to use. Contains no solvents, diluents or volatiles
- Easy application; only contact pressure required during heat cure
- Superior chemical resistance
- Exceptionally high temperature resistance
- Low exotherm upon curing.
Best regards,
Igor Novák
Dear Dr. Rajendra R. Desmukh,
You could use an electrically conductive epoxy based adhesive with a low electrical resistance of 10-5 Ohm.cm.
Best regards,
Igor Novák
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