The derivative of triazolo/benzimidazoquinazolinones is prepared via silica-promoted solvent-free method using microwave irradiation with an excellent yield. The newly synthesized compounds were characterized by various techniques like IR, NMR and Mass spectroscopy. The compound with 1a was crystallized and analysed by single crystal X-ray diffraction studies.

Present investigation focusses on combined effect of B4C and SiC on the improvement in hardness with an average size of 35-40μm on Al6061 hybrid composite. Composites are produced by stir casting process. The effect of artificial aging treatment with different aging temperatures of 100, 150 and 200OC on the improvement in hardness is also investigated. Optical micrographs and Brinell hardness number have been discussed. An attempt is made to find out the intermetallic phase responsible for strengthening by Transmission Electron Microscopy. Due to positive response to age hardening treatment there is an improvement in the mechanical properties of Al6061 alloy & its hybrid composite. The aging kinetics is more accelerated in case of hybrid composites as compared to unreinforced Al6061 alloy because of presence of reinforcement particulate, which act as nucleation site for precipitation. Artificially aged at 100OC shows improvement in hardness by 120-220% due to the precipitation of secondary solute rich phase of alloying elements as compared Al6061 alloy.

Abstract. It is well recognized that mechanical surface enhancement methods can significantly improve the characteristics of highly-stressed metallic components. Deep cold rolling is one of such technique which is particularly attractive since it is possible to generate, near the surface, deep compressive residual stresses and work hardened layers while retaining a relatively smooth surface finish. In this paper, the effect of turn-assisted deep cold rolling on AISI 4140 steel is examined, with emphasis on the residual stress state. Based on the X-ray diffraction measurements, it is found that turn-assisted deep cold rolling can be quite effective in retarding the initiation and initial propagation of fatigue cracks in AISI 4140 steel.

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This paper presents manufacturing of metallic composites using stir-casting method. The setup details and manufacturing methodology are explained. Microstructure and characterization of graphite-tin composite is also included. The tensile strength and hardness improvement is observed in tin-graphite MMC with increase in weight percentage of graphite. Metal-matrix composites (MMC's) are now attracting enormous interest. One of the prime reasons for this is that significant advances have been made in recent years on the development of fabrication routes, which are economically attractive and generate material of high micro structural quality. In particular, it is possible to produce composites, which are relatively free from gross defects (Clyne and Mason, 1987; Smith and Froes, 1984; Rodes and Spuurling, 1985; Hunt, 1989; Ted Guo and Tsao, 2000). However, it depends on the ability of synthesizing them with a consistent reproducibility in microstructure and properties. With continual development in fabrication techniques, MMC's have been found to be suitable to replace some of the conventional metallic monolithic alloys.