(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室， 長沙 410083)
摘 要: 以Mo、 W和Si粉為原料， 采用自蔓延熱爆合成制備了不同組分的MoSi2WSi2復(fù)合粉末，并利用X射線衍射儀和掃描電鏡對合成產(chǎn)物進(jìn)行了相組成和產(chǎn)物形貌分析。 結(jié)果表明： 熱爆反應(yīng)產(chǎn)物純凈， MoSi2WSi2復(fù)合粉末中只有MoSi2和WSi2兩相存在； 顆粒的大小取決于體系的摩爾生成焓， 摩爾生成焓越大， 顆粒長大越顯著； 熱爆合成反應(yīng)以Si的熔化為先導(dǎo)， 反應(yīng)機(jī)制為熔化-溶解-析出-長大機(jī)制。
關(guān)鍵字: MoSi2WSi2復(fù)合粉末; 自蔓延熱爆合成; 合金化
by thermal explosion mode of SHS
（State Key Laboratory of Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract: MoSi2WSi2 composite powders with different molar ratios were prepared by the thermal explosion mode of SHS using Mo, W and Si powders. The phase and morphology of the synthesized products were investigated by X-ray diffractrometry and scanning electron microscopy. The results show that there are only MoSi2 and WSi2 two phases in the reacted products. The molar formation enthalpy of the system determines the particle size. The bigger the molar formation enthalpy is, the more obvious the particles grow. Thermal explosion synthesis is preceded by melting of Si particles, and it proceeds in a melting-dissolving-precipitating-growing mechanism.
Key words: MoSi2WSi2 composite powders; thermal explosion mode of SHS; alloying
