微波烧结TiC/Ti6Al4V复合材料的高温氧化行为

摘要

TiC/Ti6Al4V composites were fabricated by microwave sintering.The isothermal oxidation behaviors of the TiC/Ti6Al4V composites were investigated in air under the temperature of 550,650 and 750 ℃.Moreover,the surface and cross-sectional morphologies and phase composition of the oxidation film were investigated.The results show that the TiC/Ti6Al4V composites are composed of TiC,α-Ti+β-Ti phases.With increase of the oxidation temperature,the oxidation rule curves change from parabola into line.The oxidation products of the composites mainly consist of TiO2 as the oxidation temperature lower than 650 ℃.While the oxidation temperature is high up to 750 ℃,the oxidation coatings are composed of three layers,containing thin outer TiO2 ,intermediate Al2 O3 and TiO2 and inner TiO2 .With the TiC content increases,the oxygen activation energy increases,the particle size of ox-ide decreases and the oxidation resistance of TiC/Ti6Al4V composites improves.%采用微波烧结法制备TiC/Ti6Al4V复合材料,研究TiC/Ti6Al4V复合材料在550、650和750℃空气中的恒温氧化行为,并对氧化膜的表面、截面形貌及相组成进行了分析。结果表明：TiC/Ti6Al4V 复合材料由 TiC、ɑ-Ti+β-Ti三种物相组成。随着氧化温度的增加,TiC/Ti6Al4V复合材料的氧化规律由抛物线型转变为直线型,在650℃温度以下,复合材料的氧化产物主要由TiO2组成,而750℃时氧化层主要有外层极薄的 TiO2、中间层Al2 O3和TiO2混合区及大部分内层TiO2三部分组成。随着 TiC含量增加,氧化激活能增大,氧化物粒径减小, TiC/Ti6Al4V复合材料的抗氧化性能也越好。