Materials Science Forum Vol. 808

Abstract: Stainless steel (SS) is sensitized by thermal treatment in the range of 450°C to 800°C and inter-granular attack would occur upon subsequent exposure to certain media. This study is focused on modelling the effect of sensitization (by taking into consideration hardness as the weld property) in resistance spot welding (RSW) of 304SS, before and after cryogenic treatment on tungsten electrode. In the present work, outcome of Taguchi model has been used for developing a mathematical model for sensitization; using Buckingham’s π-theorem. The parameters of significance are coolant flow rate (CFR), voltage and time. This study will provide main effects of these variables on hardness of weld joint and will shed light on the sensitization mechanism in RSW of 304SS. The comparison with experimental results will also serve as further validation of model.

Abstract: The impact of Rapid Prototyping (RP) on the future engineering and manufacturing will undoubtedly be widespread .It has variety of applications which include the manufacture of prototypes know as rapid prototyping, tool cores and cavities know as rapid tooling and in the manufacture of patterns for a range of casting processes known as rapid casting. In the proposed research work, fused deposition modeling (FDM) technique of RP will be used for development of a tool for direct application using Rapid tooling. The research work includes development of new hybrid feedstock filament of Fe – Nylon6 composite material for the FDM machine which will be suitable for the machine in its existing setup. The feedstock filament will have the desired mechanical thermal and rheological properties as desired for Rapid Tooling applications. The proposed feedstock material will be ferromagnetic in nature and can find wide application in industrial applications.

Abstract: Aluminium metal matrix composite (Al-MMC) is the most promising area for the researcher to develop a material of high strength, elastic modulus and wear resistance and low co-efficient of thermal expansion and weight. Un-hybrid and hybrid Al-MMC can be developmed by physical combination of aluminium with single and multiple reinforcement material, respectively. The improvement in mechanical properties has been achived with the reinforcement of Al₂O₃, SiC and combination of Al₂O₃, SiC (hybrid). Hybrid Al-MMCs are found superior to un-hybrid Al-MMCs in terms of wear properties. The fabrication of hybrid Al-MMC can be done with vacuum assisted moulding process (V process) in which no binder is used, which possesses many benefits over other sand casting processes. This production route will revolutionize the automobile and other industries.