Material Description of TiB2
Nearly fully dense polycrystalline TiB2 can be produced by various processing methods, including sintering, hot pressing, hot isostatic pressing, microwave sintering, and dynamic compaction. However, the relatively strong covalent bonding of the constituents results in low self-diffusion rates. Consequently, given also a high melting point of (3225±20) °C, pressureless sintering of TiB2 requires a relatively high sintering temperature, on the order of 2000 °C. Unfortunately, grain growth is also accelerated by the higher temperature, and the anisotropy of the hexagonal grain structure results in deleterious internal stresses and the onset of spontaneous microcracking during cooling. Grain growth can be limited and densification enhanced using sintering aids such as Cr, CrB2, C, Ni, NiB, and Fe. The solubility of TiB2 in liquid Ni and Fe appears to be especially useful in this regard. In such cases, the mass fraction of the sintering aid in the specimen may range from 1 % to 10 %, while the sintering temperature may be reduced to 1700 °C to 1800 °C for sintering times on the order of 1 h. Successful hot pressing with Ni additives can be achieved with a hot pressing temperature as low as 1425 °C with a sintering time of 2 h to 8 h. When sintering aids are used in the composition, the theoretical maximum density, ρtheo, can be different from the density of the pure crystal, ρxtal, because of the different mass density of the sintering aid and the influence of the sintering aid on the lattice parameters. If you are looking for high quality, high purity, and cost-effective Titanium diboride, or if you require the latest price of Titanium diboride, please feel free to email contact mis-asia.