With the imposition of sanctions against Russian aviation industry companies, the issue of import substitution for polymer composite materials (PCM) has become particularly pressing. AeroComposit JSC and Irkut Corporation PJSC (Yakovlev PJSC) set ITEKMA LLC an ambitious task: replacing imported cold-curing epoxy adhesives Hysol 9394 and Hysol 9396, which are used in the manufacture of most civil aircraft worldwide, as well as in the repair of composite parts without removing them from the aircraft, thanks to their high adhesion to PCM and excellent physical and mechanical properties.
ITEKMA LLC and INUMiT JSC successfully completed the task and developed a family of structural two-component cold-curing epoxy adhesives for a wide range of applications.
Low-viscosity adhesive A-77N was developed as an alternative to EA9396 and VK-27 adhesives, which are widely used in the manufacture and repair of polymer composite materials and metals. A-77N adhesive has a long pot life (up to 2.5 hours) and low exothermicity, while adhesive joints made with it boast a long service life (short-term durability up to +250°C). The adhesive is certified, has passed all climatic and durability tests, and has been successfully used in the manufacture of the "black" wing of the MS-21 aircraft family.
A-77N achieves its key physical and mechanical properties within just one day of curing at room temperature, making it fully comparable to Hysol 9396. A subsequent six-day post-curing period after releasing the bonding pressure allows for necessary auxiliary operations to be performed without slowing the production cycle or for repairs. Among other uses, A-77N adhesive is already widely used for the injection-molded installation of sleeves in honeycomb panels.
Thixotropic adhesives AT-44K, AT-44M, and AT-44D are designed for filling gaps up to 3 mm when assembling composite structures and metal parts. AT-44D is used in assemblies requiring high dielectric properties. AT-44M has the highest mechanical properties in the AT-44 adhesive family, but only at temperatures up to +85°C.
AT-44K was developed as an alternative to EA9394 adhesive and is used as a "liquid gasket" during jig assembly, ensuring joint resistance to high shear and bending loads in temperatures ranging from -60 to +180°C (short-term up to +250 ° C). Its high fuel resistance allows it to be used directly in aircraft torsion box fuel tanks. Adhesive joints based on AT-44K exhibit excellent resistance to mechanical processing, resisting chipping and cracking. AT-44 series adhesives have found application in programs at JSC Kronstadt and JSC UZGA, and have also been widely used in the assembly of a long-life prototype of a PCM wing for a wide-body aircraft.
The cold-curing epoxy adhesives A-77N and AT-44, developed by ITEKMA LLC and INUMiT JSC, are currently finding increasing use in the aviation and unmanned aerial vehicle industries in Russia.
You can find out more about the range of these and other adhesives by following the link.