Abstract

N-type Fe/sub 0.98/Co/sub 0.02/Si/sub 2/ powders have been produced by mechanical alloying process and consolidated by vacuum hot pressing. As-milled powders were in a metastable state and fully transformed to /spl beta/-FeSi/sub 2/ phase by subsequent isothermal annealing. However, as-consolidated iron silicides consisted of untransformed mixture of /spl alpha/-Fe/sub 2/Si/sub 5/ and /spl epsiv/-FeSi phases. Isothermal annealing has been carried out to induce the transformation to a thermoelectric semiconducting /spl beta/-FeSi/sub 2/ phase. The transformation behavior of /spl beta/-FeSi/sub 2/ was investigated a modified TGA, SEM and XRD analyses. Isothermal annealing at 830/spl deg/C in vacuum led to the /spl beta/-FeSi/sub 2/ phase transformation, but some residual metallic /spl alpha/- and /spl epsiv/-phases were unavoidable. Microstructures of iron silicides were investigated using SEM. Microharness before and after isothermal annealing was evaluated and correlated with the phase transformation as well as thermoelectric properties.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.