组元配比对球磨固态燃烧式反应和扩散型反应的影响

Effect of component proportion on solid state combustive reaction and solid state diffusional reaction during high energy ball milling

采用搅拌式高能球磨机研究了不同铝含量的Al/CuO球磨固态燃烧反应和Al -Cu及Al-Cu -Al2 O3 扩散型反应 .结果表明 :理想配比的Al/CuO的反应孕育期最短 ,偏离这一配比 ,孕育期延长 ,反应由整体燃烧式逐渐过渡到渐进燃烧式完成 ;球磨强度扩大以燃烧式进行的组元配比范围 ;当铝含量超过理想配比中的比例 ,随Al含量增加 ,反应由单一的还原反应向还原 +合成复合反应模式转化 ,反应产物为平衡组织 ,依次为Cu +Al2 O3、Cu9Al4 +Al2 O3、CuAl2 +Al2 O3、Al(Cu) +Al2 O3;而球磨Al-Cu和Al-Cu -Al2 O3 体系的反应以扩散方式进行 。

The combustive reactions of CuO with different Al contents and the diffusional reactions of Al-Cu and Al-Cu-Al 2O 3 during high energy ball milling have been invetigated using a self made attritor. The shortest activation time before ignition is found at the stoichiometry of CuO and Al. The activation time increases when the composition of the powder mixtures deviates from the stoichiometry, and the occurrence of reactions changes from a combustive way to a gradual way. The increase in rotation speed is able to enlarge the range of the composition of Al/CuO which may be induced by ball milling in a combustive way. With increasing of the Al content in the off stoichiometric powder mixtures, the reaction mode changes from a single reduction reaction to a reduction synthesis composite reaction, and the reaction products are equilibrium microstructures in the sequence: Cu+Al 2O 3, Cu 9Al 4+Al 2O 3, CuAl 2+Al 2O 3 and Al(Cu)+Al 2O 3. The reactions of Al-Cu-Al 2O 3 and Al-Cu systems induced by ball milling take place in a diffusional manner, whose products are non equilibrium microstructures in contrast to the former ones.