Articles written in Sadhana

    • Investigations on microstructural and microhardness developments in sintered iron–coal fly ash composites


      More Details Abstract Fulltext PDF

      The present work is aimed to explore the microstructural and mechanical characteristics of coal-fly ash reinforced iron metal-matrix composites (IMMCs), synthesized through powder metallurgy technique. Coalfly ash wt%, compacting load and sintering temperature were considered as the input variables, whereas sintered density and microhardness of the composites were taken as the output responses. Flowability and compressibility of the starting materials were demonstrated using Hausner ratio and Carr’s index. Decorous morphological,crystallographic and elemental characteristics of the starting materials and IMMCs were deliberated using Scanning electron microscopy, X-ray diffraction and Energy-dispersiveX-ray spectroscopy investigations respectively. A significant improvement in the microhardness of IMMCs by 50% and drop in density by 35% were found at 15 wt% as compared to 0 wt% reinforcement. The substantial increase in the microhardness eventually resulted in an increase in their specific microhardness by a factor of two. Significant improvements inthe microhardness of IMMCs at 15 wt % of reinforcement, compacted at 10 ton and sintered at 1150°C were found to be prompted by the strengthening mechanisms like load transfer, Hall–Petch effect and Taylor strengthening. The analytically calculated microhardness in the light of strengthening mechanisms was found smaller than the corresponding experimental values as a function of wt % of reinforcement. Further, statistical analysis of the obtained results was carried out using response surface methodology

    • Production, characterisation and utilisation of grinding swarf/ feedstock for synthesis of metal matrix composite through powder metallurgy process: A short communication


      More Details Abstract Fulltext PDF

      This article is intended to demonstrate an innovative idea wherein trash of grinding swarf could be converted into treasure of metal matrix composite (MMC). The grinding swarf produced during the slitting operation of structural-mild steel using a high-speed cut-off saw was characterised for morphology, mineralogy and rheology. Scanning electron microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD) characterisation of the grinding swarf and MMC were carried out to deliberate their morphological, elemental and microstructural attributes. The rheological attributes of the swarf were quantified through the Hausner ratio, Carr’s index and angle of repose. The rheological, microstructural, morphological andelemental analysis of the grinding swarf exhibited their suitability to be used as feedstock for the powder metallurgy (P/M) process. Since the feedstock contained a mixture of soft steel chips and harder iron oxide layered spherical particles, the feedstock was processed through the P/M process to synthesise the MMC. The feedstock was compacted in a hardened steel die using a uniaxial hydraulic press at 200 MPa pressure. Subsequently, the sintering of the green compact was carried out at 1150°C in an inert environment. The green andsintered densities of the MMC were evaluated through the conventional and Archimedes principle respectively. The green and sintered densities were found as 4.78±0.01 g/cm3 and 5.12±0.01 g/cm3, respectively. Further, the average microhardness of the MMC evaluated by Vicker’s hardness tester was 336 Hv0.05. The overall physio-mechanical properties of the composite were revealed by a specific microhardness as 65.62, which is even better than some of the aluminium-MMCs.

  • Sadhana | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2022-2023 Indian Academy of Sciences, Bengaluru.