Authors: Yatir Sadia Liron Dinnerman Yaniv Gelbstein
Publish Date: 2013/02/20
Volume: 42, Issue: 7, Pages: 1926-1931
Abstract
The present challenges in the energy crisis require finding new ways to reduce consumption of fossil fuels Thermoelectrics can help reduce fuel consumption by producing electricity from waste heat The higher manganese silicides HMS have shown promise in this field as inexpensive nontoxic and highly stable ptype thermoelectric materials One of the production techniques for HMS is mechanical alloying by ball milling In this research the effect of the ballmilling duration and speed on the phases produced was studied Mn and Si powders were milled at speeds of 200 RPM to 800 RPM for 1 h to 7 h Xray diffraction XRD results of the samples prepared using mechanical alloying show deterioration into the MnSi phase The sample that underwent 5 h of milling at 800 RPM showed the greatest amount of HMS phase and was subsequently spark plasma sintered The sample showed insufficient thermoelectric properties ZT ≈ 01 at 450°C compared with either solidstate reaction samples showing ZT ≈ 04 or cast samples showing ZT ≈ 063 at 450°C The reduced ZT values of the mechanically alloyed and sparkplasmasintered samples were attributed to the high relative amount of MnSi phase The correlation between the relative amount of MnSi and the transport properties is described in detail
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