• R K Ray

      Articles written in Bulletin of Materials Science

    • Phase transitions in molybdenum sesquisulphide systems between 80 and 600 K

      A K Rastogi R K Ray

      More Details Abstract Fulltext PDF

      Samples of Mo2S3 system and substituted derivatives with Cr, Nb, Cu and Mn have been studied. The resistivity, thermoelectric power, magnetic susceptibility and specific heat indicate clear phase transition at temperatures between 200 and 310 K. X-ray investigations establish the transitions at these temperatures as structural changes. Careful analysis of the data helps to obtain working values for a model for the energy band. Carrier density, effective mass, mobility, band overlap parameter, density of states for the electrons and holes in the overlapping bands at the Fermi level and the band gap for a higher conduction band are obtained.

    • Evolution and stability of texture during thermomechanical processing of Ti-24Al-11Nb alloy

      Satyam Suwas R K Ray

      More Details Abstract Fulltext PDF

      The evolution of basal texture during thermomechanical processing of Ti-24Al-11Nb alloy has been studied as a function of different processing variables like hot rolling temperature, amount of deformation, cooling conditions etc. The stability of the deformation texture during post-rolling annealing and during theα2βα2 phase transformation cycle was also investigated. Unrestricted rolling of primaryα2 to maximum thickness reduction at the lowest rolling temperature has been found to be most favourable for obtaining a good basal texture. Texture of transformed (secondary)α2 is generally non basal when the transformation takes place from deformedβ. Rolling texture does not seem to change during annealing leading to recrystallization. Theα2βα2 phase transformation cycle does not change the starting basal texture and a starting non basal texture also does not give rise to basal texture due to this treatment.

  • 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.