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. 2018 Jul 16;11(7):1219.
doi: 10.3390/ma11071219.

Synthesis of Non-Stoichiometric (TiNb)C 0.5 With High Hardness and Fracture Toughness Under HTHP

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Free PMC article

Synthesis of Non-Stoichiometric (TiNb)C 0.5 With High Hardness and Fracture Toughness Under HTHP

Zhichao Zhang et al. Materials (Basel). .
Free PMC article

Abstract

Nonstoichiometric TiC0.5 and (TiNb)0.5 powders were prepared by the mechanical alloying process using Ti, Nb, and TiC powders as raw materials. Furthermore, the as-prepared TiC0.5 and (TiNb)0.5 powders were used as initial materials to fabricate TiC0.5 and (TiNb)0.5 compacts under high pressures and high temperatures (HTHP) of 5.5 GPa and 1200⁻1550 °C for 5 min. Phase identification and microstructure of the mechanical-alloyed powders and the sintered TiC0.5 and (TiNb)0.5 compacts were realized by an X-ray diffractometer and scanning electron microscope. The results indicate that the as-prepared TiC0.5 and (TiNb)0.5 powders have a similar crystal structure of face-centered cubic (FCC) to TiC. The sintered (TiNb)0.5 compact has good Vickers hardness (~16 GPa), and notably, excellent fracture toughness (~7.3 MPa·m1/2). The non-stoichiometric compound not only reduced the sintering temperature of covalent compounds, but also greatly enhanced the mechanical properties of the materials. Thus, we have provided a novel synthetic strategy for the production of a compound with high-strength covalent bonds.

Keywords: fracture toughness; high temperature and high pressure; mechanical alloying; non-stoichiometric compound; sintering.

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
(a) X-ray diffraction (XRD) patterns of as-prepared non-stoichiometric TiC0.5 powder and TiC0.5 compacts sintered at different temperatures; and (b) grain size and strain of as-prepared non-stoichiometric TiC0.5 powder and compacts sintered at 5.5 GPa and different temperatures.
Figure 2
Figure 2
XRD patterns of theoretically calculated and experimentally obtained TiC0.5.
Figure 3
Figure 3
Fractured surface of the TiC0.5 compacts sintered at high temperature and high pressure (HTHP): (a) 1200 °C; (b) 1300 °C; (c) 1400 °C; and (d) 1500 °C.
Figure 4
Figure 4
Microhardness and fracture toughness of TiC0.5 compacts sintered at HTHP.
Figure 5
Figure 5
XRD patterns of as-prepared non-stoichiometric (TiNb)C0.5 powder, (TiNb)C0.5 compacts sintered at different temperatures and theoretically calculated TiC and NbC.
Figure 6
Figure 6
Fractured surface of (TiNb)C0.5 compacts sintered at different temperatures and element surface distribution of samples. (ac), Microscopic morphology of the fracture of (TiNb)C0.5 samples sintered at 1350 °C (a), 1450 °C (b), and 1550 °C (c), respectively. (df), Carbon atom (d), Titanium atom (e), Niobium atom, and (f) surface distribution of samples after being sintered at 1550 °C.
Figure 7
Figure 7
Microhardness and fracture toughness of compacts sintered at HTHP.

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References

    1. Zeng W., Gan X., Li Z., Zhou K. Effect of TiC addition on the microstructure and mechanical properties of TiN-based cermets. Ceram. Int. 2017;43:1092–1097. doi: 10.1016/j.ceramint.2016.10.046. - DOI
    1. Fu Z., Koc R. Sintering and mechanical properties of TiB2-TiC-Ni using submicron borides and carbides. Mater. Sci. Eng. A. 2016;676:278–288. doi: 10.1016/j.msea.2016.08.110. - DOI
    1. Xiong H., Li Z., Zhou K. TiC whisker reinforced ultra-fine TiC-based cermets: Microstructure and mechanical properties. Ceram. Int. 2016;42:6858–6867. doi: 10.1016/j.ceramint.2016.01.069. - DOI
    1. Souček P., Daniel J., Hnilica J., Bernátová K., Zábranský L., Buršíková V., Stupavská M., Vašina P. Superhard nanocomposite nc-TiC/a-C:H coatings: The effect of HiPIMS on coating microstructure and mechanical properties. Surf. Coat. Technol. 2017;311:257–267. doi: 10.1016/j.surfcoat.2017.01.021. - DOI
    1. Cai X.L., Xu Y.H., Zhao N.N., Zhong L.S., Zhao Z.Y., Wang J. Research on Mechanical Characteristic of Micro-Nano Structure TaC Ceramic by Nanoindentation. Surf. Coat. Technol. 2016;299:135–142. doi: 10.1016/j.surfcoat.2016.05.004. - DOI
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