The precipitation of TiB2 in aluminum alloy melts from the exothermic reaction of K2TiF6 and KBF4 halide salts and evaluation of its mechanical properties.

Aluminum alloy 2014-TiB2 metal matrix composites have been fabricated using an exothermic reaction process at 850 degrees C using K2TiF6 and KBF4 halide salts. The period of exothermic reaction was varied from a minimum of 15 min to a maximum of 45 min to investigate the relationship between the degree of reaction and the growth behavior of TiB2. Micro structural observation showed a decreasing trend in grain size of the composites as the period increases. An x-ray diffractometer was used to confirm the presence of TiB2. SEM micrographs observation revealed the hexagonal shape of the in-situ TiB2 particles. Exothermic reaction is completed with the increase in reaction time, but the size of the in-situ TiB2 particles was less depending on reaction time. As the period of exothermic reaction increases the weight percentage of TiB2 increases but decrease in the grain size. Hence the yield strength, ultimate tensile strength and microhardness of the composite were increased.