原位生成陶瓷相结合Ti(C,N)复合材料及其性能研究

In-situ formed ceramic bonded Ti(C,N)composites and their properties

以TiO_(2)粉、鳞片石墨和Si粉为原料,采用碳热还原氮化法在1450℃保温2 h制备了陶瓷相结合Ti(C,N)复合材料。研究了Si粉加入量(加入质量分数分别为0、5%、15%、25%)对材料物相组成、显微结构、物理性能及抗氧化性的影响。结果表明:适量Si粉的引入有利于细化Ti(C,N)晶粒,提高Ti(C,N)复合材料的常温力学性能与抗氧化性。当Si粉加入量为5%(w)时,原位生成陶瓷相结合Ti(C,N)复合材料的综合性能较优,其显气孔率、常温抗折强度和常温弹性模量分别约为(38.8±1.6)%、(62.5±2.4)MPa及(59.6±2.2)GPa。随Si粉加入量(w)进一步增加至15%或25%,复合材料的体积密度和力学性能下降。

Ceramic bonded Ti(C,N)composites were prepared by carbothermal reduction nitridation at 1450℃for 2 h using TiO_(2) powder,flake graphite and Si powder as raw materials.The effects of the Si powder addition(0%,5%,15%,and 25%,by mass)on the phase composition,the microstructure,the physical properties,and the oxidation resistance of the material were investigated.The results show that the appropriate addition of Si powder refines the Ti(C,N)grains and improves the cold mechanical properties and the oxidation resistance of Ti(C,N)composites.The in-situ formed ceramic bonded Ti(C,N)composite with 5%Si powder has the optimal comprehensive properties,with the apparent porosity of(38.8±1.6)%,the cold modulus of rupture of(62.5±2.4)MPa,and the cold elastic modulus of(59.6±2.2)GPa.When the Si powder addition increases to 15%or 25%,the bulk density and the mechanical properties of the composite decrease.