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, Dario; Deorsola, FABIO ALESSANDRO; Tresso, Elena Maria; 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]

Spark plasma sintering of self-propagating high-temperature synthesized TiC0.7/TiB2 powders and detailed characterization of dense product

VALLAURI, Dario;DEORSOLA, FABIO ALESSANDRO;TRESSO, Elena Maria;
2009

Abstract

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.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2270654
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