• D K Bhattacharya

      Articles written in Bulletin of Materials Science

    • Image analysis system for quantitative metallography

      V K Chadda D G Joshi S N Murthy S V Kulgod C Baburao D K Bhattacharya Baldev Raj

      More Details Abstract Fulltext PDF

      This paper describes a Z-80 microprocessor-based image analyzer developed for global parameter evaluation of images over a 256 × 256 pixel frame. It consists of a microscope,ccd scanner, 6-bit videoadc, Z-80 computer and an image display monitor. Facilities are provided for feature erosion/dilation and halo correction. The paper also presents the details of another more powerful user microprogrammable HP1000 minicomputer-based image analysis system under development. This system consists of an optical microscope/epidiascope coupled to a chalnicon scanner. Here the 512 × 512 pixel image is acquired with 8-bit resolution. It provides for shading correction, auto-delineation, image processing and image analysis functions for evaluation of various basic and derived parameters.

      Both the systems are software intensive and are realised according to requirements of quantitative metallography. They can also be used for analysis of images obtained in the fields of biology, medicine, geological survey, photography and space.

    • Studies on indentation fracture toughness on ceramic and ceramic composite using acoustic emission technique

      A K Ray G Das N K Mukhopadhyay D K Bhattacharya E S Dwarakadasa N Parida

      More Details Abstract Fulltext PDF

      This paper is aimed at investigating the acoustic emission activities during indentation toughness tests on an alumina based wear resistant ceramic and 25 wt% silicon carbide whisker (SiCw) reinforced alumina composite. It has been shown that the emitted acoustic emission signals characterize the crack growth during loading and unloading cycles in an indentation test. The acoustic emission results indicate that in the case of the composite the amount of crack growth during unloading is higher than that of loading, while the reverse is true in case of the wear resistant ceramics. Acoustic emission activity observed in wear resistant ceramic is less than that in the case of composite. An attempt has been made to correlate the acoustic emission signals with crack growth during indentation test.

  • Bulletin of Materials Science | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2017-2019 Indian Academy of Sciences, Bengaluru.