摘要
以Ti,Al和TiC为原材料,用无压煅烧合成法制备三元化合物Ti_3AlC_2。详细讨论了煅烧温度和铝含量对多晶Ti_3AlC_2纯度的影响。利用X射线衍射仪、场发射扫描电镜和场发射透射电镜研究了粉末材料的组织结构、晶粒大小、层板厚度和选区电子衍射花样。结果表明1300℃是合成Ti_3AlC_2粉末的最佳煅烧温度,1:1.2:2是Ti/Al/TiC原材料的最佳摩尔比。用热压法制备了不同烧结温度下的Ti_3AlC_2块体试样,在1300℃热压制备的Ti_3AlC_2块体的相对密度可达99.9%,其维氏硬度和三点抗弯强度分别为5.7 GPa和630 MPa。通过场发射扫面电镜观察材料的断口形貌,进一步分析了Ti_3AlC_2块体材料的强化机理。
A method for fabrication of ternary compound Ti3AlC2 powder by pressureless calcining（PC） technique was developed. Powders of Ti, Al and TiC were mixed as staring materials. The effects of calcining temperature and aluminum content on the purity of Ti3AlC2 were discussed. The reaction mechanism and the microstructure evolution of Ti3AlC2 prepared at different temperatures were investigated by X-ray diffraction, field emission scanning electron microscopy and high resolution transmission electron microscopy. Results indicate that the single-phase polycrystalline Ti3AlC2 powders are obtained at 1300 ℃ which possesses a typical laminated structure, and the best molar ratio of raw Ti/Al/TiC materials is 1：1.2：2. The bulk samples sintered by hot pressing were from the Ti3AlC2 powders. After hot pressing of different temperatures, the fully dense bulk Ti3AlC2 shows the best properties when prepared at 1300 ℃. The density of bulk Ti3AlC2 reaches to 99.9%. The average Vickers hardness is around 5.7 GPa, and the maximum flexural strength is over 630 MPa. Finally the strengthening mechanism of the bulk Ti3AlC2 was also proposed.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2017年第8期2108-2113,共6页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China(51571078)
National High-Tech Research and Development Program of China("863"Program)(2013AA051402)
