Effect of ball milling process on the in situ synthesizing of nano-TiB whiskers

Abstract:

Ball milling process has an important effect on the microstructure of final powder products and the corresponding as-sintered samples. In this study, Ti-Al-0.2B wt.% mixed powders were ball-milled by low-energy and high-energy types of ball mills, and then the milled powders were sintered by hot- pressing. On this basis, morphology evolution of the powders was analyzed, and the microstructure of the reinforcements in the as-sintered composites was investigated. In the low-energy ball milling process, mechanical alloying was occurred between the powder particles. TiB whiskers formed in sintering process were long and thin without coarse bars or clusters. For the high-energy type, the particle size was refined remarkably to 1um, and Ti (Al) supersaturated solid solution or even amorphous structure was formed during the milling process. In the following sintering process, nano-scale TiB whiskers were synthesized and they were uniformly distributed in the matrix.