In this work, the fabrication of bulk TiC0.7/TiB2 nanostructured composites through metastable transformation processing is investigated by taking advantages of two non-conventional powder metallurgy methods. First, the highly metastable TiC0.7/TiB2 agglomerated powders are synthesized by the so-called self-propagating high-temperature synthesis (SHS), followed by rapid quenching. Then, the spark plasma sintering (SPS) method is adopted to consolidate the SHSed powders. A bulk ceramic composite with nanocrystalline microstructure characterized by a high-relative density is then obtained. Dwell temperature of 1400 8C, heating time of 3 min, and total processing time equal to 5 min, while applying a mechanical pressure of 20 MPa, are found to be the optimal SPS experimental conditions in order to obtain near-fully densified samples. The obtained TiC0.7/TiB2 samples exhibit hardness HV5 as high as 24 GPa, modulus of elasticity of about 400 GPa, fracture toughness of about 5.6 MPa m1/2, and a compressive strength of about 2.9 GPa. A very low-wear rate (Wv = 3.8 106 mm3/(N m)) and a good thermal shock resistance (DTc = 250 8C) are also displayed. In addition, a high-abrasive wear factor (AWF) equal to 1.84 is evaluated on the basis of the achieved mechanical properties. These results make the obtained TiC0.7/TiB2 composite suitable for wear resistant parts as well as cutting tool materials.
Spark plasma sintering of self-propagating high-temperature synthesized TiC0.7/TiB2 powders and detailed characterization of dense product / MUSA C.; LOCCI A. M.; LICHERI R.; ORRÙ R.; CAO G.; VALLAURI D.; DEORSOLA F.A.; TRESSO E.; SUFFNER J.; HAHN H.; KLIMCZYK P.; JAWORSKA L.. - In: CERAMICS INTERNATIONAL. - ISSN 0272-8842. - STAMPA. - 35(2009), pp. 2587-2599. [10.1016/j.ceramint.2009.02.018]
|Titolo:||Spark plasma sintering of self-propagating high-temperature synthesized TiC0.7/TiB2 powders and detailed characterization of dense product|
|Data di pubblicazione:||2009|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.ceramint.2009.02.018|
|Appare nelle tipologie:||1.1 Articolo in rivista|