Non-isothermal oxidation kinetics of WC-6Co cemented carbides in air

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• 作者：Liyong Chen ; Bin Wang ; ^{wangbin325@263.net} ; Danqing Yi ; Huiqun Liu
• 关键词：WC&ndash ; 6Co ; Non-isothermal oxidation ; Kinetic
• 刊名：International Journal of Refractory Metals and Hard Materials
• 出版年：2013
• 出版时间：September, 2013
• 年：2013
• 卷：40
• 期：Complete
• 页码：19-23
• 全文大小：580 K

文摘

The oxidation of WC-Co cemented carbides cutting tools is a key factor in determining tools' life during dry and high speed cutting. Thus, its investigation is of great importance to the design and development of cutting tool materials. In this paper, the non-isothermal oxidation of WC-6Co cemented carbides was carried out on simultaneous thermogravimetry-differential scanning calorimetry (TG-DSC) thermal analyzer (Netzsch STA 449C) between room temperature and 1273 K at different heating rates (¦Â = 5, 10, 15 and 20 K/min) in a dry air atmosphere under the atmospheric pressure. The results show that, with the heating rate increasing from 5 K/min to 20 K/min, the extrapolated initial temperature (T_ei), the peak temperature (T_p), and the extrapolated final temperature (T_ef) of the oxidation of WC-6Co cemented carbides increased from 957 K to 997 K, from 1014 K to 1079 K, and from 1030 K to 1094 K, respectively. The apparent activation energy (E_a) of the oxidation of WC-6Co cemented carbides was 206.85 kJ/mol calculated by Flynn-Wall-Ozawa (FWO) method, and preexponential factor (A) was 5.02 ¡Á 10⁹ min^? 1. The oxidation experiment data of WC-6Co was in good agreement with R2 kinetic model. The reaction rate can be described by d¦Á/dt = 10¹⁰exp(? 24,879 / T)(1 ? ¦Á)^1/2.