Two-step synthesis of TiC_0.7N_0.3@WC-MoC₂ core-shell microspheres and fabrication of TiC_0.7N_0.3@WC-MoC₂-based cermets by SPS

Abstract

The precursor with TiC_0.7N_0.3@WO₃-MO₃ microspheres were prepared by a novel method from the WO₃-MoO₃ sol dipping. Subsequently, TiC_0.7N_0.3@WC-MoC₂ core-shell structural microspheres were successfully obtained by carburizing the precursor at 900 °C in a flowing mixture of CH4 (20 ml · min⁻¹) and H₂ (200 ml · min⁻¹) for 2 h. Then TiC_0.7N_0.3@WC-MoC₂-15Co cermets were prepared utilizing the core-shell powders by spark plasma sintering (SPS). Powders of the precursors with TiC_0.7N_0.3@WO₃-MO₃ microspheres, TiC_0.7N_0.3@WC-MoC₂ microspheres and TiC_0.7N_0.3@WC-MoC₂-15Co cermets were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The obtained TiC_0.7N_0.3@WC-MoC₂ microspheres have a dense WC-MoC₂ coatings shell. The thickness of the shell could be easily controlled by adjusting the number of sol dipping cycles. It was found that the TiC0.7N_0.3@WC-MoC₂ microspheres were more beneficial to fabricate the “core-rim” structures by SPS.

Keywords

core-shell structure / spark plasma sintering (SPS) / microstructure / fabrication

References

[1] Zackrisson J., Andrén H.O. Effect of Carbon Content on the Microstructure and Mechanical Properties of (Ti, W, Ta, Mo)(C, N)-(Co, Ni) Cermets[J]. International Journal of Refractory Metals & Hard Materials, 1999, 17(4): 265-273.

[2] Mari D., Bolognini S., Feusier G., Cutard T., Viatte T., Benoit W. TiMoCN Based Cermets. Part II. Microstructure and Room Temperature Mechanical Properties[J]. International Journal of Refractory Metals & Hard Materials, 2003, 21: 47-53.

[3] Zhang X.B., Liu N., Rong C.L., Zhou J. Microstructure and Mechanical Properties of TiC-TiN-Zr-WC-Ni-Co Cermets[J]. Ceramics International, 2009, 35: 1187-1193.

[4] Ahn S.Y., Kang S. Effect of WC Particle Size on Microstructure and Rim Composition in the Ti(C_0.7N_0.3)-WC-Ni System[J]. Scripta Materialia, 2006, 55: 1015-1018.

[5] Xiong J., Guo Z.X., Shen B.L., Cao D. The Effect of WC, Mo₂C, TaC Content on the Microstructure and Properties of Ultra-fine TiC_0.7N_0.3 Cermets[J]. Materials and Design, 2007, 28(5): 1 689-1 694.

[6] Wang J., Liu Y., Zhang P., Ye J.W., Tu M.J. Effect of VC and Nano-TiC Addition on the Microstructure and Properties of Micrometer Grade Ti(CN)-based Cermets[J]. International Journal of Refractory Metals & Hard Materials, 2009, 30(6): 2 222-2 226.

[7] Mari D., Bolognini S., Viatte T., Benoit W. Study of the Mechanical Properties of TiCN-WC-Co Hardmetals by the Interpretation of Internal Friction Spectra[J]. International Journal of Refractory Metals & Hard Materials, 2001, 19: 257-265.

[8] Park S., Kang S. Toughened Ultra-fine (Ti, W)(CN)-Ni Cermets[J]. Scripta Materialia, 2005, 52: 129-133.

[9] Shen X.Q., Jing M.X., Li W.X., Li D.H. Fabrication of Fe-, Ni- and FeNi-coated Al₂O₃ Core-shell Microspheres by Heterogeneous Precipitation[J]. Powder Technology, 2005, 160: 229-233.

[10] Xu W.P., Xu B.S., Zhang W., Wu W.X. Erosion-corrosion Behaviors of High Velocity Arc Sprayed Fe-Al/Cr₃C₂ Coating[J]. Journal of Wuhan University of Technology Materials Science Edition, 2006, 21(3): 29-31.

[11] Ghaziof S., Golozar M.A., Raeissi K. Characterization of Asdeposited and Annealed Cr-C alloy Coatings Produced from a Trivalent Chromium Bath[J]. Journal of Alloys and Compounds, 2010, 496: 164-168.

[12] Gao L., Wang H., Kawaoka H., Sekino T., Niihara K. Fabrication of YAG-SiC Nanocomposites by Spark Plasma Sintering[J]. Journal of European Ceramic Society, 2002, 22: 785-789.

[13] Li X., Chib A., Sato M., Takashash S. Strength and Superconductivity of Nb₃Al Prepared by Spark Plasma Sintering[J]. Journal of Alloys and Compounds, 2002, 336: 232-236.

[14] Ritasalo R., Cura M.E., Liu X.W., Soderberg O., Ritvonen T., Hannula S.P. Spark Plasma Sintering of Submcro-sized Cu-Powder-Influence of Processing Parameters and Powder Oxidization on Microstructure and Mechanical Properties[J]. Materials Science and Engineering A, 2010, 557: 2 733-2 737.

[15] Feng P., Xiong W.H., Yu L.X., Zheng Y., Xia Y.H. Phase Evolution and Microstructure Characteristics of Ultrafine Ti(C,N)-based Cermet by Spark Plasma Sintering[J]. International Journal of Refractory Metals & Hard Material, 2004, 22: 133-138.

[16] Alvarez M., Sánchez J.M. Spark Plasma Sintering of Ti(C,N) Cermets with Intermetallic Binder Phases[J]. International Journal of Refractory Metals & Hard Material, 2007, 25: 107-118.

[17] Patra A., Auddy K., Ganguli D., Livage J., Biswas P.K. Sol-gel Electrochromic WO₃ Coatings on Glass[J]. Materials Letters, 2004, 58: 1 059-1 063.

[18] Yang H.M., Shi R.R., Zhang K., Hu Y.H., Tang A.D., Li X.W. Synthesis of WO₃/TiO₂ Nanocomposites via Sol-gel Method[J]. Journal of Alloys and Compounds, 2005, 398: 200-202.