论文部分内容阅读
采用FAPAS法制备了超硬AlMgB_(14)/TiB_2复合陶瓷材料,分别采用扫描电镜(SEM)及能谱(EDS),X射线衍射仪分析添加超细TiB_2第二相颗粒对复合材料微观形貌及韧性的影响;通过高温摩擦磨损试验分析了复合材料在25,300,500℃下的抗磨损性能及其摩擦学特征。结果表明,添加30%(质量分数)的微纳米级TiB_2后,AlMgB_(14)/TiB_2复合材料的平均硬度达32.5 GPa,断裂韧性由未添加时的3.0 MPa·m~(1/2)提高到3.95 MPa·m~(1/2);摩擦系数在室温及300℃时介于0.4~0.55之间,500℃时达0.65左右,磨损率1.27×10~(-6)~6.62×10~(-6) mm~3/(N·m)。随着摩擦温度的升高,试样摩擦学性能发生变化,由于摩擦表面产生氧化物的润滑作用,摩擦系数在300℃时略有减小,磨损机理由室温时的磨粒磨损转变为高温下的粘着磨损脱落。
The superhard AlMgB_ (14) / TiB_2 composite ceramics were prepared by FAPAS method. The microstructure of the composites was analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray diffraction (EDS) And toughness. The wear resistance and tribological properties of the composites at 25,300 and 500 ℃ were analyzed by high temperature friction and wear tests. The results showed that the average hardness of AlMgB_ (14) / TiB_2 composites reached 32.5 GPa and the fracture toughness increased from 3.0 MPa · m ~ (1/2) without addition of 30% (mass fraction) To 3.95 MPa · m 1/2. The friction coefficient was between 0.4 and 0.55 at room temperature and 300 ℃, 0.65 at 500 ℃, and the wear rate was 1.27 × 10 -6 ~ 6.62 × 10 ~ (-6) mm ~ 3 / (N · m). With the increase of the friction temperature, the tribological properties of the samples changed. Due to the lubricating effect of oxide on the friction surface, the friction coefficient slightly decreased at 300 ℃. The wear mechanism changed from abrasive wear at room temperature to high temperature The adhesive wear off.