三维连续网络Ti_(2)AlC/TiAl复合材料高温摩擦磨损行为研究

High-Temperature Friction and Wear Behavior of Three-Dimensional Continuous Network Ti_(2)AlC/TiAl Composites

采用真空热压制备了三维连续网络Ti_(2)AlC/TiAl复合材料,在明晰其高温氧化行为的基础上,利用摩擦磨损试验机对复合材料的高温氧化磨损行为及其机理进行了研究。结果表明,高温氧化条件下,复合材料表面在600℃以下生成Al_(2)O_(3)藓状氧化物,在800℃时生成TiO_(2)聚集团以及TiO_(2)和Al_(2)O_(3)的氧化物混合层;随着温度的升高,氧化膜的润滑作用使得摩擦系数降至0.3237,基材的软化与TiO_(2)聚集团的突出生长使得磨损速率逐渐升至4.5×10^(-4) mm^(3)/(N·m),磨损机理由磨粒磨损转变为磨粒磨损与氧化磨损的混合磨损。

Three dimensional continuous network Ti_(2)AlC/TiAl composites were prepared by vacuum hot pressing.The high temperature oxidation behavior and mechanism of the composites were studied by friction and wear tester.The results show that under the high temperature oxidation condition,Al_(2)O_(3) mossy oxide forms on the surface of the composite below 600℃,and the TiO_(2) agglomerate and the mixed layer of TiO_(2) and Al_(2)O_(3) form at 800℃.With the increase of temperature,the friction coefficient decreases to 0.3237 due to the lubrication of the oxide film,and the softening of the substrate and the prominent growth of TiO_(2) agglomerates make the wear rate increase to 4.5×10^(-4) mm^(3)/(N·m).The abrasive wear is transformed into the mixed wear of abrasive wear and oxidation wear.