-
摘要本课题以Al，TiO2，B2O3粉末为原料运用原位合成技术，制备(Al2O3+TiB2)/Al复合材料。通过DSC,SEM，XRD,EDS等手段,研究反应过程及机理，分析球磨时间、增强体体积分数和升温速率对反应活化能的影响。结果表明，反应体系Al-TiO2-B2O3有三个分步反应：19596
- 上一篇：超细碳化物硬质合金的制备研究
- 下一篇：CoSb3基半导体温差发电材料的热电性能优化研究
(1)Al+TiO2→α-Al2O3+3[Ti]
(2)15Al+7B2O3→7α-Al2O3+AlB12+2B
(3)5Al+6TiO+Ti2O3+AlB12+4B→3Al2O3+8Ti
反应产物中α-Al2O3颗粒具有偏聚的现象，TiB2颗粒均匀分布在Al基体上。当增强体体积分数为30%,球磨时间为4h,烧结保温时间为30min时,部分TiB2小颗粒会被α-Al2O3包裹起来形成内晶颗粒。球磨时间增加，反应活化能增大，但球磨时间增至8小时时减小。增强相体积分数增加，反应（2）的活化能值增大，而反应（3）的活化能值减小，反应更加剧烈,第（3）反应峰面积明显增大。升温速率提高，放热峰均向高温方向移动。
关键词：反应机理 铝基复合材料 球磨时间 活化能
毕业设计说明书（论文）外文摘要
Title The effect of milling time and volume fraction on the
reaction dynamic in the system of Al-TiO2-B2O3
Abstract
In the topic, with the help of situ synthesis technology, We apply Al,TiO2 and B2O3 powder as raw materials to make out Al2O3, TiB2 reinforced aluminum matrix composites. By the means of DSC, SEM, XRD, EDS, we study the mechanism of the reaction process and analysis the effect of milling time, volume fraction and heating rate on the activation energy. The results indicate that Al-TiO2-B2O3 reaction system owns three steps :
(1) Al + TiO2 → α-Al2O3 +3 [Ti] (2) 15Al +7 B2O3 → 7α-Al2O3 + AlB12 +2 B
(3) 5Al +6TiO + Ti2O3 + AlB12 +4 B → 3Al2O3 +8Ti
One of the reaction product α-Al2O3 particles have a segregation phenomenon.TiB2 particles uniformly distribute in the Al matrix. When the volume fraction of reinforced phase is 30%, the milling time is 4h, Sintering at 1200 ℃ for 30mins, a small portion of TiB2 particles would be surrounded by α-Al2O3 particles to form inter-crystalline particles.With the increase of milling time, activation energy increases. However, it comes down when the milling time is eight-hour. With the increase of the volume fraction, the activation energy of the second reaction increases, while the third’s decreases. The reaction becomes more severe. Peak area of the third reaction increases significantly. With the increase of heating rate, the exothermic peak shows on a higher temperature.
Keywords:reaction mechanism;aluminum matrix composite; milling time; activation energy
目 次
1引言 1
1.1复合材料的制备方法 1
1.2本课题的研究目的及内容 3
2 实验 5
2.1 实验原料 5
2.2 实验设备 5
2.3 实验工艺流程图 6
2.4 实验步骤 6
3实验结果分析 10
3.1热力学分析 10
3.2 DSC分析 11
3.3 反应组织的显微组织分析 19
3.4反应活化能的计算和影响因素分析 20
结 论 24
致 谢 25
参考文献 26