Microstructural studies on the pressure-temperature treated nickel specimens

Bhaskaran, TA and Parameswara, MA and Mohan, Murali (1994) Microstructural studies on the pressure-temperature treated nickel specimens. In: Proceedings of the National Conference on High Pressure Science and Technology, 10-11 Oct 1994, Bangalore, India.

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    Abstract

    Annealed nickel wire-specimens have been subjected to N 5.5 GPa and to different temperatures in the range 550-750 K using an externally heated tungsten carbide opposed anvil apparatus with talc as a pressure transmitter. The13; microhardness measurements on the recovered specimens exhibited an increase in the range 15-35 % in the values oveT those obtained on the as- annealed specimens. This suggests work-hardening effects during the pressurization.13; However, the optical micrographs of these specimens do not show any evidence of plastic deformation. The transmission electron microscopic studies on annealed nickel wafers recovered after pressurization (2-10 GPa at 300 K) under13; talc pressure medium provide microstructural evidences for the deformation of the specimen. The deformation microstructure consists of a sequential evolution, with increasing pressure, of (i) dislocation cells, (ii) dense dislocation walls, and (iii) features leading to the formation of subgrains. This suggests that the plastic deformation of the specimens increases with increase in pressure. The dislocation density in the annealed specimens before pressurization is - 2x10' cm-', and increases to - 10quot; cm-' after pressurization

    Item Type: Conference or Workshop Item (Paper)
    Uncontrolled Keywords: Microstructure;Pressure temperature;Nickel specimens
    Subjects: PHYSICS > Physics(General)
    Division/Department: Materials Science Division, Materials Science Division, Materials Science Division
    Depositing User: M/S ICAST NAL
    Date Deposited: 29 Jul 2008
    Last Modified: 17 Jun 2010 13:54
    URI: http://nal-ir.nal.res.in/id/eprint/4903

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