标题：A study on in situ growth of TaC whiskers in A1_2O_3 matrix powder for ceramic cutting tools
作者：Guolong Zhao;Chuanzhen Huang;Hanlian Liu;Liang Xu;Xuewen Chong;Bin Zou;Hongtao Zhu
作者机构：[Zhao, G] Centre for Advanced Jet Engineering Technologies (CaJET), School of Mechanical Engineering, Shandong University, Jinan 250061, China, Key La 更多
通讯作者地址：[Huang, CZ]Shandong Univ, Sch Mech Engn, CaJET, Jinan 250061, Peoples R China.
来源：Materials Research Bulletin: An International Journal Reporting Research on Crystal Growth and Materials Preparation and Characterization
关键词：A. Composites;B. Crystal growth;C. Electron microscopy;C. X-ray diffraction;D. Microstructure
摘要：In situ growth of tantalum carbide (TaC) whiskers was synthesized in an α-Al_2O_3 matrix powder via a carbothermal reduction technique within a temperature range of 1350-1500 ℃ in an argon atmosphere. The starting materials consisted of Ta_2O_5, C, Ni and NaCl powders. Different mixing methods and various reaction temperatures were employed. Most of the prepared whiskers were 0.2-0.5 μm in diameter and 5-15 μm in length. The reaction temperature of 1400-1450℃ was suitable for the growth of TaC whiskers and a wet mixing method was beneficial to increase the whisker yield. Some of the whiskers exhibited the needle shape while others exhibited the screw shape. The growth mechanism of the whiskers was a complex mechanism involving a helical screw dislocation mechanism and a vapor-liquid-solid process. No obvious influences of the Al_2O_3 matrix powder on the growth of TaC whiskers were found and the major impurities in the obtained powder were TaC particles, nickel and unreacted carbon.