东南大学学报（自然科学版）
東南大學學報（自然科學版）
동남대학학보（자연과학판）
JOURNAL OF SOUTHEAST UNIVERSITY
2009年
5期
1033-1037
,共5页
β-FeSi2热电材料%机械合金化%掺杂%热电性能
β-FeSi2熱電材料%機械閤金化%摻雜%熱電性能
β-FeSi2열전재료%궤계합금화%참잡%열전성능
β-FeSi_2 thermoelectric materials%mechanical alloying%doping%thermoelectric properties
用机械合金化法成功制备了配比为Fe_(1-x)Co_xSi_2(x=0.04,0.05,0.06)的N型β-FeSi_2基热电材料.研究结果表明:在球料质量比为80∶ 1,球磨速度为400 r/min的条件下,球磨20 h的粉体发生完全合金化,生成β-FeSi_2,α-Fe_2Si_5和ε-FeSi的合金相;经过1 373 K退火2 h,再结合1 073 K退火2 h的热处理后,可完全获得晶粒细小的N型块状β-FeSi_2;随着测量温度的升高,Fe_(1-x)Co_xSi_2试样的Seebeck系数α和电导率σ增大,热导率κ降低,无量纲热电优值ZT随温度升高而明显增大;随着掺杂量的增加,材料的电导率σ增大,热导率κ降低,σ/κ比值得到提高,但Seebeck系数α降低;当T=695 K,掺杂量x=0.04时,Seebeck系数α的最大绝对值为227 μV/K;具有最佳热电优值的材料为Fe_(0.95)Co_(0.05)Si_2.
用機械閤金化法成功製備瞭配比為Fe_(1-x)Co_xSi_2(x=0.04,0.05,0.06)的N型β-FeSi_2基熱電材料.研究結果錶明:在毬料質量比為80∶ 1,毬磨速度為400 r/min的條件下,毬磨20 h的粉體髮生完全閤金化,生成β-FeSi_2,α-Fe_2Si_5和ε-FeSi的閤金相;經過1 373 K退火2 h,再結閤1 073 K退火2 h的熱處理後,可完全穫得晶粒細小的N型塊狀β-FeSi_2;隨著測量溫度的升高,Fe_(1-x)Co_xSi_2試樣的Seebeck繫數α和電導率σ增大,熱導率κ降低,無量綱熱電優值ZT隨溫度升高而明顯增大;隨著摻雜量的增加,材料的電導率σ增大,熱導率κ降低,σ/κ比值得到提高,但Seebeck繫數α降低;噹T=695 K,摻雜量x=0.04時,Seebeck繫數α的最大絕對值為227 μV/K;具有最佳熱電優值的材料為Fe_(0.95)Co_(0.05)Si_2.
용궤계합금화법성공제비료배비위Fe_(1-x)Co_xSi_2(x=0.04,0.05,0.06)적N형β-FeSi_2기열전재료.연구결과표명:재구료질량비위80∶ 1,구마속도위400 r/min적조건하,구마20 h적분체발생완전합금화,생성β-FeSi_2,α-Fe_2Si_5화ε-FeSi적합금상;경과1 373 K퇴화2 h,재결합1 073 K퇴화2 h적열처리후,가완전획득정립세소적N형괴상β-FeSi_2;수착측량온도적승고,Fe_(1-x)Co_xSi_2시양적Seebeck계수α화전도솔σ증대,열도솔κ강저,무량강열전우치ZT수온도승고이명현증대;수착참잡량적증가,재료적전도솔σ증대,열도솔κ강저,σ/κ비치득도제고,단Seebeck계수α강저;당T=695 K,참잡량x=0.04시,Seebeck계수α적최대절대치위227 μV/K;구유최가열전우치적재료위Fe_(0.95)Co_(0.05)Si_2.
Co-doped N-type β-FeSi_2 thermoelectric materials Fe_(1-x)Co_xSi_2( x =0. 04, 0. 05, 0. 06) are successfully prepared by mechanical alloying method. It is indicated that under the condition of balls to powders mass ratio of 80: 1, rotation speed of 400 r/min and milling time of 20 h, powders are composed of β-FeSi_2, α-Fe_2Si_5 and s-FeSi intermetallic compound. And, a single-phase Co-doped N-type β-FeSi_2 bulks with refined grain can be obtained after annealing at 1 373 K for 2 h and 1 073 K for 2 h. With the increase of measuring temperature, Seebeck coefficient α, electric conductivity σ and thermoelectric figure of merit ZT increase directly while thermal conductivity κ decreases inversely; with the increase of Co addition, σ ascends while κ and α of Fe_(1-x)Co_xSi_2 alloy reduce, leading to a growth of the ratio σ/κ. When the temperature reaches 695 K and the amount of Co-addition x gets 0. 04, Seebeck coefficient shows the maximum absolute value of 227 μV/K. The maximum figure of merit is obtained in Fe_(0.95)Co_(0.05) Si_2.
