Obtaining superhard composites of the BL group in the cBN(Al)-SiB4-WC system under high pressure and high temperature conditions
DOI:
https://doi.org/10.15407/dopovidi2019.08.052Keywords:
cBN, cutting ceramics, high pressures, silicon borides, superhard materialsAbstract
The processes of formation of ceramicmatrix materials in the cBN(Al)-SiB4 WC system under high pressure conditions (7.7 GPa) in the temperature range of 1600-2300 °C are studied. It is shown that, for the composition chosen by us (BL group), 60 % vol. cBN, 5 % vol. Al, 25 % vol. SiB4 and 10 % vol. WC, nonporous superhard materials are virtually formed in the entire temperature range with hardness of no less than 33 GPa and Young’s modulus of 613 GPa, which is attributable to the formation of a highstrength ceramic matrix both as a result of the liquidphase sintering using aluminium and of an active chemical interaction of silicon tetraboride with WC. It is demonstrated by experiments that the micropowder consolidation process should be carried out at temperatures of no less than 1800 °C. The heating of the system above 2200 °C leads to the excessive cBN graphitization and accumulative recrystallization in general. According to the XRD analysis, it was established that, as a result of the thermal decomposition of silicon tetraboride and further chemical reaction with WC, new compounds are formed: W2B5 and WSi2, and the original aluminum is oxidized to α-Al2O3, thereby relieving the system of excess oxygen. All new compounds formed in the course of producing the ceramics are represented by microcrystalline forms, not exceeding 1—3 μm in size, that are arranged in the intergranular space of the core matrix, which contributes to an additional increase in hardness and fracture resistance. The obtained superhard ceramic plates can be used for turning tempered (up to 60 HRC) and highalloyed (including inconel) steel at rising temperatures in the cutting area.
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Wentorf, R. H., DeVries, R. C. & Bundy, F. P. (1980). Sintered superhard materials. Science (80), 208, No. 4446, pp. 873880. doi: https://doi.org/10.1126/science.208.4446.873
Chiou, S. Y., Ou, S. F., Jang, Y. G. & Ou, K. L. (2013). Research on CBN/TiC composites Part1: Effects of the cBN content and sintering process on the hardness and transverse rupture strength. Ceram. Int., 39, pp. 72057210. doi: https://doi.org/10.1016/j.ceramint.2013.02.066
Costes, J. P., Guillet, Y., Poulachon, G. & Dessoly, M. (2007). Toollife and wear mechanisms of CBN tools in machining of Inconel 718. Int. J. Mach. Tools. Manuf., 47, Iss. 7, pp. 1081. doi: https://doi.org/10.1016/j.ijmachtools.2006.09.031
Huang, Y., Chou, Y. K. & Liang, S. Y. (2007). CBN tool wear in hard turning: A survey on research progresses. Int. J. Adv. Manuf. Technol., 35, No. 5–6, pp. 443453. doi: https://doi.org/10.1007/s00170-006-0737-6
Barry, J. & Byrne, G. (2001). Cutting tool wear in the machining of hardened steels. Wear, 247, No. 2, pp. 139151. doi: https://doi.org/10.1016/S0043-1648(00)00528-7
Benko, E., Stanislaw, J. S., Królicka, B., Wyczesany, A. & Barr, T. L. (1999). ñBNTiN, cBNTiC composites: Chemical equilibria, microstructure and hardness mechanical investigations. Diam. Relat. Mater., 8, No. 10, pp. 18381846. doi: https://doi.org/10.1016/S0925-9635(99)00131-4
Bezhenar, M. P., Bozhko, S. A., Garbuz, T. O., Bilyavina, N. M. & Markiv, V. Ya. Titanium/aluminium diborides in composites produced by the reaction sintering at high pressures in the cBN—TiC—Al. Sverchtv. Mater., 2008, No. 5, pp. 4050. doi: https://doi.org/10.3103/S1063457608050067
Petrusha, I. A. et al. (2015). Preventive action of silicon nitride at HTHP sintering of cubic boron nitride. J. Superhard Mater., 37, Iss. 4, pp. 222233. doi: https://doi.org/10.3103/S1063457615040024
Abukhshim, N. A., Mativenga, P. T. & Sheikh, M. A. (2006). Heat generation and temperature prediction in metal cutting: A review and implications for high speed machining. Int. J. Mach. Tools and Manuf., 46, No. 78, pp. 782800. doi: https://doi.org/10.1016/j.ijmachtools.2005.07.024
Lin, H. M., Liao, Y. S. & Wei, C. C. (2008). Wear behavior in turning high hardness alloy steel by CBN tool’. Wear, 264, No. 78, pp. 679684. doi: https://doi.org/10.1016/j.wear.2007.06.006
Luo, S. Y., Liao, Y. S. & Tsai, Y. Y. (1999). Wear characteristics in turning high hardness alloy steel by ceramic and CBN tools. J. Mater. Process. Technol., 88(13), pp. 114121. doi: https://doi.org/10.1016/S0924-0136(98)00376-8
Slipchenko, K. V., Petrusha, I. A., Stratiichuk, D. A. & Turkevich, V. Z. (2018). The influence of the VCAl additive on wear resistance of cBNbased composites. J. Superhard Mater., 40, No. 3, pp. 226227. doi: https://doi.org/10.3103/S1063457618030115
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