金刚石含量与粒度对自蔓延高温烧结钛铝碳结合剂/金刚石复合材料组织与形貌的影响  

Effect of diamond size and content on the phase composition and morphology of Ti_2AlC bonded diamond obtained by self-propagation high temperature sintering

作　　者：梁宝岩[1] 王艳芝[1] 张旺玺[1] 王俊和[1] 闫帅帅[1] 穆云超[1] 

机构地区：[1]中原工学院材料与化工学院,郑州450007

出　　处：《粉末冶金技术》2016年第1期35-42,共8页Powder Metallurgy Technology

基　　金：河南省教育厅重点项目(13A430132);河南省教育厅自然科学研究计划(14A430007)项目;河南省基础与前沿技术研究计划(132300410164);河南省省院科技合作项目(122106000051;142106000193);河南省科技开放合作项目(142106000051);河南省高校创新团队项目(15IRTSHN004)

摘　　要：采用Ti、Al、石墨和金刚石粉体为原料,通过自蔓延高温烧结制备Ti2AlC结合剂/金刚石复合材料,研究金刚石含量和粒度对该复合材料的物相组成与显微形貌的影响。结果表明,原料粉末发生自蔓延反应,可生成Ti2AlC基体相,同时亦生成TiC和Al_3Ti相。金刚石粒度较细(W5)时,金刚石表面C元素充分地与Ti反应生成TiC,同时基体主相变成TiC和Al,没有Ti_2AlC形成。当金刚石粒度较粗(30/40目)时,基体的主相为Ti_2AlC;金刚石与基体结合紧密。当添加金刚石粒度为120/140目时,基体的主相为Ti_2AlC和TiC。当采用170/200目金刚石为原料时,研究金刚石含量对复合材料基体组成与显微组织的影响时,发现原料中添加10%与20%的金刚石后得到的样品基体的主相为Ti_2AlC、TiC和Al3Ti相与金刚石;金刚石表面均包覆着良好的TiC与Ti_2AlC组织。但是当金刚石含量增加至30%时,基体的主相为TiC,同时含有少量的Ti_2AlC、Ti和Al_3Ti等相;金刚石表面受到一定程度的侵蚀,被一些TiC晶粒所包裹。提出一个Ti-Al-石墨-金刚石体系的自蔓延反应机制,即Ti和Al首先发生化学反应,生成Al_3Ti并放出大量的热,然后,原料中的石墨与金刚石表面转变的石墨都与Ti反应形成TiC,TiC与周围的Ti-Al相不断反应形成Ti2AlC。最后,基体主相为Ti_2AlC,金刚石表面亦形成Ti2AlC。Ti2Al C ceramic boned diamond composites were fabricated by Self-propagation High Temperature Sintering（ SHS） from Ti/Al/graphite/Diamond raw powders. The effect of diamond＇s content and size on phase and microstructure of composites were studied. The result shows that Ti2 Al C phases can be obtained from Ti/Al/graphite /Diamond powders by SHS. Meanwhile,Ti C Al3 Ti phases are also obtained. Diamond＇s content and size have a significant impact on the state of diamond and the composition of matrix in composites. When the diamond size is finer（ W5）,C elements of diamond surface react sufficiently with Ti to form Ti C,which affects the matrix synthesis. And the main phases of matrix are Ti C and Al,no Ti2 Al C formed. When diamond size is larger（ 30 /40 mesh）,the reaction degree on diamond surface is lower. The main phase of matrix is Ti2 Al C. Diamond has a good bondcombination with the matrix. When diamond size is 120 /140 mesh,the main phase of matrix is Ti_2Al C and Ti C.Effect of diamond content on the phase composition and microstructure of composites was studied when the size of diamond was selected as 170 /200 mesh. The main phases of the matrix of samples are Ti_2AlC,TiC and Al_3Ti when10% or 20% diamond is added. The surface of diamond is well wrapped by TiC and Ti_2AlC organization. When diamond content is increased to 30%,the main phase of the matrix is Ti C. Additionally,small amounts of Ti_2AlC,Ti and Al_3Ti phase are also obtained. Meanwhile,diamond is eroded a certain extent,which is wrapped by Ti C grains. One SHS reaction mechanism of Ti/Al/graphite/Diamond system was proposed. Ti reacts with Al to form Al_3Ti,releasing amounts of heat. And then,graphite from raw materials and from the surface of diamond react with Ti to form Ti C. Finally,Ti C reacts with Ti-Al phases to form Ti_2AlC. Hence,the main phase of the matrix is Ti_2AlC. Meanwhile,Ti_2AlC lathed grains are formed on the surface of diamond.

关 键 词：TI2ALC 金刚石 自蔓延高温烧结 

分 类 号：TQ163[化学工程—高温制品工业]