热压法制备Ti_3SiC_2陶瓷结合剂/金刚石复合材料的组织结构

Microstructure of Ti_3SiC_2/diamond composite materials prepared by hot-pressing

以Ti、Si、C粉、金刚石磨料为原料,添加适量Al粉,采用热压法制备Ti3SiC2陶瓷结合剂/金刚石复合材料,通过X射线衍射、扫描电镜及能谱分析对该复合材料的组织结构进行观察与分析,并研究烧结温度、助熔剂Al含量以及金刚石浓度对复合材料的影响。结果表明,因金刚石的反应活性较差,较低温度下热压时金刚石表面未能生长出Ti3SiC2,1300℃高温下热压形成的Ti3SiC2晶粒发育良好;适量添加Al粉有助于Ti3SiC2的合成;金刚石颗粒浓度从25%增加到50%时,金刚石参与并促进Ti3SiC2的合成,Ti3SiC2含量明显增加;金刚石表面生成晶型发育良好的Ti3SiC2晶粒,实现了磨料与结合剂的化学键合,从而提高结合剂与磨料间的结合力。

Ti3SiC2 bonded diamond composite materials were prepared by hot-pressing using Ti, Si, C and diamond powders as the raw materials, Al as the adjuvant. The phase composition and microstructure of prepared composite were analyzed by XRD, SEM and EDS. Effects of sintering temperature, content of Al and concentration of diamond on the microstructure of Ti3SiC2 bonded diamond composite materials were also studied. The results show that, no Ti3SiC2forms on the surface of diamond at lower hot-pressing temperature because of the poor activity of diamond, the crystal structure of Ti3SiC2 can grow well when hot-pressed at 1 300 ℃, appropriate Al adding is beneficial to the synthesis of Ti3SiC2. With increasing concentration of diamond from 25% to 50%, Ti3SiC2 content increases obviously, which demonstrates that diamond can participate and promote the formation of Ti3SiC2. Ti3SiC2 grains growing well on the surface of the diamond can obtain the chemical bonding between abrasive and binder and enhance the holding force of bond to diamond.