Shashi Kumar M. E.

Presently there are lot of materials that can be used in the fabrication of any item, so choosing a material is a major criteria. So the materials are chosen depending on the properties desired by the resulting item. The composite materials have better properties when compared with its individual components, metals and ceramics. The overall appeal of the product depends mainly on its durability, aesthetics and its final cost. Composite materials are cost effective and significantly satisfy the needs of the clients. By utilizing composite materials we can obtain high strength to weight ratio at a relatively economical cost. Moreover, they can be produced easily by basic part forming. Hybrid polymer composites have been studied of late which improves a specific property of the composite that is under question. Here a hybrid composite made of laminate of Nomex and HS glass sheets with varying percentage (1% - 2.5 %) of bisphenol dispersed in resin is prepared. The same samples were subjected to cryogenic treatment (24 hrs and 72 hrs). The results of tensile strength, flexural strength and hardness were compared for all the specimens 24 hrs cryogenic, 72hrs cryogenic and non-treated specimens. The results showed that the hardness of the cryogenic treated bisphenol based PMCs has increased with the weight percentage of Bisphenol indicating the fact that the laminates can withstand more loads at subzero temperatures The increase observed was about 3 – 4 % more in terms of BHN number. At the same time the tensile and flexural strengths have considerably reduced after treating the PMC cryogenically as the laminates becomes more brittle when treated. The tensile strength increased by about 10% approximately and the flexural strength reduced by 300%