Abstract:
The TiB
2/Al composite ingot was prepared by the fluoride salt reaction method, and the TiB
2/Al composite powders were prepared by the high pressure gas atomization. The structures and properties of the composite ingot and powders were characterized by metallographic microscope, scanning electron microscope, X-ray diffractometer, and particle size distribution instrument. The results demonstrate that, the solubility product of TiB
2 in Al melt is much smaller than that of the TiAl
3 and AlB
2 phases in the experiment condition, the change of Gibbs free energy caused by the precipitation of TiB
2 from Al melt is more negative than that caused by the precipitation of TiAl
3 or AlB
2 from Al melt. The TiB
2/Al composite ingot and powders are mainly composed of α-Al matrix and TiB
2 phase. The TiB
2 particles in the TiB
2/Al composite powders prepared by gas atomization have nano-scale, and uniformly disperse in the Al matrix, no obvious segregation phenomenon is observed. The size distribution of the TiB
2/Al composite powders exhibits a normal state in the range of 10~100 μm. The powder yield with the particle size between 10~70 μm is 81.1%, the yield for the particle larger than 70 μm is 12.6%, and that less than 10 μm is 6.3%.