原位合成铝基复合材料凝固组织中TiB_2粒子的特征

Characterization of TiB_2 particles in solidification structuresof in situ processed aluminum matrix composites

分析了原位合成制备的ＴｉＢ２ 粒子强化铝基复合材料不同凝固组织中ＴｉＢ２ 粒子的分布规律和形貌特征。研究结果表明， ＴｉＢ２ 在该复合材料中细化晶粒的作用较弱， 但有明显的聚集倾向， 其聚集程度与熔炼方式和加热温度有关； 经半固液成型处理的组织中ＴｉＢ２ 的分布特征未改善； 六边形和长条形ＴｉＢ２ 可以是同一形态的粒子在空间不同方位的表现， 六边形ＴｉＢ２ 的侧面为｛１２１０｝ 面； 测定了ＴｉＢ２粒子的尺寸分布。

Analysis was performed on the cast microstructures of in situ processed aluminum matrix composites reinforced by TiB 2 particles with the emphases on their distribution and morphology. TiB 2 particles have no remarkable grain refining effect, but a strong tendency of agglomeration, which depended on melting methods as well as heating temperatures. No improvement of particle distribution was observed in the thixoformed structure. It is shown that rectangular and hexagonal morphologies of TiB 2 can stem from a same plate like particle in different spatial positions. It was observed that the lateral planes of a plate like TiB 2 particle can be {1210}. The size distribution of TiB 2 was measured with imaging analyzer.