Rapid synthesis of ternary carbide Ti3SiC2 through pulse-discharge sintering technique from Ti/Si/TiC powders
Rapid synthesis of ternary carbide Ti3SiC2 through pulse-discharge sintering technique from Ti/Si/TiC powders
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DOI：
10.1007/s11661-002-0320-1
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发表时间：
2002-11
期刊：
影响因子：
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通讯作者：
Zhe-feng Zhang;Zhengming Sun;H. Hashimoto
中科院分区：
文献类型：
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作者：
Zhe-feng Zhang;Zhengming Sun;H. Hashimoto
采用混合法制备了Ti/Si/TiC（摩尔比为1：1：2（M1）和2：2：3（M2））粉末，在Ar气氛中反应24 h合成了三元碳化物Ti 3SiC 2。合成过程在1200 °C至1400 °C下在50 MPa的压力下使用脉冲放电烧结（PDS）技术进行。烧结后，采用X射线衍射（XRD）技术分析了样品的物相组成和显微结构，并通过光学显微镜和扫描电镜观察了样品的形貌。结果表明，所有样品的相组成均为Ti 3SiC 2和少量TiC，最佳烧结温度为1250 °C ~ 1300 °C。采用标准添加法计算了Ti 3SiC 2的相对含量。对于M1样品，最低的TiC含量只能降低到约3 - 4wt%，而M2样品中的Ti 3SiC 2的含量总是低于M1样品中的含量。当M2粉末在1300 °C下烧结8至240分钟时，发现TiC峰显示出非常低的强度，并且计算出相应的Ti 3SiC 2含量高于99wt%。在整个烧结温度范围内，Ti 3SiC 2的晶粒尺寸从5 - 10 μm增加到80 - 100 μm。在高于1275 °C的烧结温度下，测量M2样品的相对密度高于99%。结果表明，PDS技术可以在较低的温度范围内由Ti/Si/TiC粉末快速合成高含量的Ti 3SiC 2。
Ti/Si/TiC powders with molar ratios of 1:1:2 (M1) and 2:2:3 (M2) were prepared for the synthesis of a ternary carbide Ti3SiC2by using the mixture method for 24 hours in an Ar atmosphere. The synthesis process was conducted at 1200 °C to 1400 °C under a pressure of 50 MPa, using the pulse-discharge sintering (PDS) technique. After sintering, the phase constituents and microstructures of the samples were analyzed by X-ray diffraction (XRD) technique and observed by optical microscopy and scanning electron microscopy. The results showed that the phases in all the samples consisted of Ti3SiC2and small amounts of TiC, and the optimum sintering temperature was found to be in the relatively low range of 1250 °C to 1300 °C. By the standard additive method, the relative content of Ti3SiC2was calculated. For the M1 samples, the lowest TiC content can be only decreased to about 3 to 4 wt pct, whereas the content of Ti3SiC2in the M2 samples is always lower than that in the M1 samples. When the M2 powder was sintered at 1300 °C for 8 to 240 minutes, the TiC peaks were found to show a very low intensity, and the corresponding content of Ti3SiC2was calculated to be higher than 99 wt pct. The grain size of Ti3SiC2increased from 5 to 10 µm to 80 to 100 µm in the entire applied sintering temperature range. The relative density of the M2 samples was measured to be higher than 99 pct at sintering temperatures above 1275 °C. It indicates that the PDS technique can rapidly synthesize high-content Ti3SiC2from the Ti/Si/TiC powders in a relatively low temperature range.