B/TiO<sub>2</sub>摩尔比对Al-TiO<sub>2</sub>-B系XD合成过程及其力学性能的影响

B/TiO₂摩尔比对Al-TiO₂-B系XD合成过程及其力学性能的影响

摘要: 主要讨论了B/TiO₂摩尔比对Al-TiO₂-B系XD(热扩散反应)合成过程及其力学性能的影响。随着B/TiO₂摩尔比从0增加到2,Al基体的晶粒细化,反应产物 Al₂O₃分布的均匀性提高;棒状物Al₃Ti的量逐渐减少直至消失;同时,该反应系的实际燃烧温度下降,反应速度减小,反应产物的致密度提高,力学性能明显改善,其抗拉强度由224.5MPa上升到354.5MPa,延伸率由3.2 %升高到5.6 %,断口中棒状物Al₃Ti逐渐消失,形成的韧窝细小而密集。

Abstract: The effects of B/TiO₂ mole rates on XD(Exothermic Dispersion) reaction and mechanical properties of Al-TiO₂-B system were studied in this paper. The test results show that with the increase of B/TiO₂ mole rate from 0 to 2, the distribution of Al₂O₃ particles was improved and the amount of Al₃Ti phase decreased and finally disappeared, the ultimate strength of the composites increased from 224.5MPa to 354.5MPa and its elongation from 3.2% to 5.8%; the actual combustion temperature and combustion velocity decreased, however, the density of combustion products increased.