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The present work focuses on comparative properties of β-naphthol based trifunctional epoxy resin and commercial epoxy resin. Reaction of β-naphthol, formaldehyde and epichlorohydrin forms trifunctional epoxy resin. β-Naphthol based trifunctional epoxy resin characterized by FT-IR, elemental analysis (C, H, N, O analyzer), epoxy equivalent weight (EEW), weight average molecular weight [Formula: see text], viscosity, rise in viscosity, hydrolysable chlorine content and volatile content. β-Naphthol based trifunctional epoxy resin cured by five different hardeners and used as matrix material for carbon reinforced composites. Composites were characterized by their mechanical properties, chemical resistance and thermal properties. Results showed excellent chemical and thermal resistance. All results were compared against commercially available epoxy resin (Diglycidyl ether of bisphenol-A based epoxy resin having EEW of 400). Results showed that β-naphthol based trifunctional epoxy resin was superior than commercial epoxy resin.

Bi-metallic welds (BMW) plays crucial and essential role in Pressurized Water Reactor (PWR) and Boiling Water Reactor (BWR), where heavy section alloys are connected to stainless steel piping systems. In Pressurized Boiling Reactor (PWR) and Boiling Water Reactor (BWR) are usually used where heavy steam flow is generated i.e. nozzles of Reactor Pressure Vessel (RPV), steam generators and pressurizers. Bi-metallic welds are often used to connect ferritic piping with austenitic piping. Recent study and experiments have shown that there are several cracking problems, fabrication induced defects, corrosion, ageing and thermal fatigue caused due to temperature changes during the whole process. Thus, here we are going to experiment with the mechanical properties and try to resolve all the above problems. The material used in present study is austenitic stainless steel 304L and carbon steel SA516 Gr.70. We welded these both materials through GTAW at different elevated currents i.e. 180 Amp, 200 Amp and 210 Amp. Filler rod used during GTAW was 309L.We made a butt joint on the plates. Hardness, Tensile and Impact test was conducted in the different parameters samples. From all the test result, it was concluded that highest heat absorption capacity was found in the sample that was welded at 200 Amp. The heat absorption capacity of the plate was 140.50 Joules. Also, lowest hardness observed was 198.33 HV 10 in the sample welded at 200 Amp. Thus, 200 Amp samples were most reliable and could reduce the above mentioned problems.

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