Structural and mechanical properties of TiB 2 and TiC prepared by self-propagating high-temperature synthesis/dynamic compaction

Titanium-diboride and titanium-carbide compacts with diameters of 100 mm and thicknesses of 25 mm were fabricated by self-propagating high-temperature synthesis/dynamic compaction (SHS/DC) of the elemental powders. Under the best conditions, the densities were greater than 99% and 96.8% of the theoretical densities for TiB 2 and TiC, respectively. The microhardness, compressive strength, and elastic modulus of the TiB 2 prepared by the SHS/DC method were comparable to reported values for hot-pressed TiB 2 . While the microhardness and elastic modulus of the TiC compacts were comparable to those for hotpressed TiC, the compressive strength was lower due to extensive cracks in the compacts. The TiB 2 prepared using a low-purity boron powder (1–5% carbon impurity) compacted to higher densities and had less cracking than that prepared using a high-purity boron powder (0.2% carbon). This result could have an impact on the cost of producing TiB 2 /TiC structural components by the SHS/DC process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44732/1/10853_2005_Article_BF01162518.pd

An investigation of the self-propagating high-temperature synthesis of Ti(Si,Al)

Copyright 2008 Elsevier B.V., All rights reserved.The self-propagating high-temperature synthesis (SPS) of TiSi and T Si,AL) powders was investigated. Elemental powders of titanium, silicon and aluminum were used for the synthesis. The sample powders were investigated by means of x-ray diffraction (XRD) with Cu radiation. It was observed that the presence of aluminum in subsequently ignited Ti-Si powder mixtures had led to reduction in the ignition temperature to between 575 °C and 590 °C. Using XRD analysis, C-54 and C-49 Ti(Si,Al) phase fields of the sample powders were identified. It was found from SEM measurements that the C-49 phase was not uniform exhibiting regions with variation in both aluminum and silicon content.Peer reviewe