TiB2 Metal Matrix Composites Research Articles

Production of Fe–B–TiB2 metal matrix composites on steel surface

Metal Matrix Composites (MMC) with boron reinforcement exhibit significant increase in the mechanical strength and wear characteristics compared to matrix alloys. Titanium Diboride (TiB2) particles have ideal properties for being used as reinforcing material due to their excellent mechanical and wear properties. This study enlightens the possibility of synthesizing Fe2B–TiB2 MMC layers on the surface of a plain steel using the plasma transferred arc (PTA) technique. The microstructure of the final alloyed layers depends on the portion of B and TiB2 powders used as covering material. TiB2 covering results in a microstructure of primary titanium diboride particles in a eutectic mixture of iron and TiB2 eutectic particles. Increasing B progressively leads to microstructures approximately described as hypoeutectic, eutectic or hypereutectic according to the Fe–B binary system, with the presence of TiB2 grains uniformly distributed throughout the alloyed layer.

The flowability of particulate TiB2-containing metal matrix composite

This paper reports a study of the flow behaviour of a particulate TiB2-containing metal matrix composite (MMC) and a SiC particulate MMC containing the same matrix alloy, both in comparison with the unreinforced matrix alloy, Al-7Si-0.4Mg.Both the MMCs exhibited a similar extreme sensitivity to surface turbulence during casting, to the point at which it was not easily possible to produce good-quality castings using a conventional gravity-poured filling system. Further results obtained from fluidity measurements showed that the fluidity is not so different to conventional casting alloys, although the fluidity of the TiB2 MMC was slightly less good than the Al-SiC metal matrix composite, which in turn was poorer than the matrix alloy. A surprising result was that increasing the casting temperature did not significantly improve the fluidity of either of the MMCs.The relatively low fluidity and the high density of major defects appears to be associated with the high viscosity of the mixture and the fact that ...