Microstructural characterization and mechanical properties of a novel TiC-based cermet bonded with Ni3(Al,Ti) and NiAl duplexalloy
A novel TiC/Ni{sub 3}(Al,Ti)-NiAl composite has been designed and synthesized by in-situ reactive hot-pressing a mixture of Ti{sub 3}AlC{sub 2} and Ni powders. After hot-press sintering at 1500 °C and 30 MPa, almost fully dense composite was obtained and the in-situ formed TiC grains were well-bonded with Ni{sub 3}(Al,Ti) and NiAl alloys. Due to the nanolaminated structure in Ti{sub 3}AlC{sub 2} materials that weakly bonded Al layers are more prone to be out-diffused from Ti{sub 3}AlC{sub 2} lattice than that of Ti atoms. The deintercalated AlTi atoms would react with Ni to give rise to the formation of Ni{sub 3}(Al,Ti) and NiAl alloys, and meanwhile a crystal lattice structure transformation happened from hexagonal Ti{sub 3}AlC{sub 2} to cubic lattice TiC. The formation of phases, grains morphologies, sintering behavior and mechanical properties were associated with sintering temperature. The as prepared TiC/Ni{sub 3}(Al,Ti)-NiAl composite under 1500 °C exhibited superior mechanical properties comparing with the counterparts fabricated under 1350 °C and 1400 °C because of the enhanced microstructures and eliminations of pores. Hardness, flexural strength and fracture toughness of the TiC/Ni{sub 3}(Al,Ti)-NiAl composite at room temperature were determined as 9.9 ± 0.35 GPa, 665 ± 26 MPa and 10.23 ± 0.4 MPa·m{sup 1/2}, respectively. Interestingly, the flexural strength and fracture toughness increases with temperature rising from 600 to 800 °C, the maximum of flexural strength and fracture toughness could reach 775 ± 25 MPa and 11.6 ± 0.4 MPa·m{sup 1/2} at 800 °C.
- OSTI ID:
- 22804845
- Journal Information:
- Materials Characterization, Vol. 135; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1044-5803
- Country of Publication:
- United States
- Language:
- English
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