Thermoelectric Properties of β-FeSi2 Mechanically Alloyed with Si and C
Thermoelectric Properties of β-FeSi2 Mechanically Alloyed with Si and C
复制标题
Si、C机械合金化β-FeSi2的热电性能
DOI：
10.2320/matertrans1989.39.1140
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Mikio Ito
中科院分区：
文献类型：
--
作者：
H. Nagai;K. Nagai;Takayuki Katsura;S. Katsuyama;K. Majima;Mikio Ito
研究了Si粉和C粉机械合金化热压n型Fe0.98Co0.02Si2和p型Fe0.92Mn0.08Si2的热电性能。结果表明，在1173 K热压1h的条件下，机械合金化（MA）对由α-Fe 2Si 5相和e-FeSi相的混合物形成β-FeSi 2相是非常有效的。热压的n型和p型样品都是由β相和少量的e相颗粒组成。随着（Si+C）添加量的增加，e相的量减少。机械合金化20 h后，在1173 K热压1 h后，形成大量20 nm左右的细小α-SiC颗粒。（Si+C）的加入显著提高了n型和p型FeSi 2的热电势，在（Si + C）质量分数为3- 4%时，热电势值均达到最大值。电阻率随（Si + C）添加量的增加而增加。（Si+C）的加入，由于α-SiC颗粒的弥散，使n型和p型FeSi 2的热导率均显著降低，从而使优值显著提高。对于n型和p型FeSi 2，优值在3-4质量%（Si+C）时最大。
The thermoelectric properties of the hot-pressed n-type Fe 0.98 Co 0.02 Si 2 and p-type Fe 0.92 Mn 0.08 Si 2 mechanically alloyed with Si and C powders have been investigated. It has been found that mechanical alloying (MA) even for a short period is very effective for forming the β-FeSi 2 phase from the mixture of the α-Fe 2 Si 5 and e-FeSi phases during hot-pressing at 1173 K for I h. Both of the hot-pressed n-type and p-type samples are composed of mostly the β-phase with a dispersion of a small amount of e-phase particles. The amount of the e-phase decreases with increasing amounts of (Si+C) addition. A lot of fine α-SiC particles around 20 nm form in the samples mechanically alloyed for 20 h and hot-pressed at 1173 K for 1 h. The addition of (Si+C) markedly increases the thermoelectric power of both n-type and p-type FeSi 2 and the thermoelectric power values are at a maximum at 3-4 mass%(Si + C) for both cases. The electrical resistivity increases with increasing amount of (Si + C) addition for both n-type and p-type FeSi 2 . The addition of (Si+C) markedly decreases the thermal conductivity of both n-type and p-type FeSi 2 due to the dispersion of fine α-SiC particles, which results in the marked increase in the figure of merit. The figure of merit values are maxima at 3-4 mass%(Si+C) for both n-type and p-type FeSi 2 .