(東北大學(xué) 材料與冶金學(xué)院， 沈陽(yáng) 110004)
摘 要: 應(yīng)用DTA技術(shù)分別測(cè)定了Mg與TiO2，Mg與B2O3及Mg與TiO2和B2O3之間的多相反應(yīng)，分析了Mg，TiO2和B2O3三相可能存在的反應(yīng)機(jī)制，應(yīng)用Freeman-Carroll法和Kissinger法計(jì)算了反應(yīng)的活化能和反應(yīng)級(jí)數(shù)。結(jié)果表明Mg-B2O3-TiO2之間的反應(yīng)為復(fù)雜的固-液-液反應(yīng)，TiO2與Mg之間的固[CD*2]液反應(yīng)放出的強(qiáng)大熱量誘發(fā)了B2O3和Mg之間的液-液反應(yīng)，而Ti與B間的反應(yīng)放出的熱量反過(guò)來(lái)又促進(jìn)前兩者的反應(yīng)。表觀活化能在溫度段760～858℃為E1=297kJ·mol-1，相應(yīng)的反應(yīng)級(jí)數(shù)分別為n1=0.8。采用Kissinger法計(jì)算的反應(yīng)級(jí)數(shù)為0.9，與Freeman-Carroll法所得的n1=0.8基本一致。
關(guān)鍵字: 動(dòng)力學(xué)； 硼化鈦的制備； 自蔓延高溫合成； 差熱分析
ZHANG Guo-yue, XU Shu-xiang, HE Ji-cheng
（School of Materials and Metallurgy, Northeastern University，
Shenyang 110006, P.R.China）
Abstract: The kinetics of preparation of titanium boride by SHS was studied. DTA curves of the reactions of Mg+TiO2，Mg+B2O3and Mg+TiO2+B2O3 were measured， compared and analyzed. It was found that the reaction of Mg+TiO2+B2O3 was a complicated reaction of solid-liquid-liquid. The surface free energy of reaction of Mg+TiO2+B2O3 was determined by the methods of Freeman-Carroll and Kissinger respectively. The results showed that E is 297kJ·mol-1 in 760～858℃， reaction progressions is n1=0.8. The reaction progressions determined by the methods of Kissinger was 0.9 and was the same mostly as that determined by the method of Freeman Carroll.
Key words: kinetics; preparation of titanium boride; SHS; DTA
