Ni含量对TiN-Ni金属陶瓷高温抗氧化性能的影响

Effect of Ni Content on the High-Temperature Oxidation Resistance of TiN-Ni Cermets

摘要:

采用热压烧结方法,分别制备了三种含Ni 30vol%、50vol%以及70vol%的TiN-Ni金属陶瓷,研究了TiN-Ni金属陶瓷在800℃静态空气中的连续氧化行为。结果表明,烧结过程中,TiN相与Ni相之间无化学反应,调整Ni含量有助于烧结致密化,其中TiN/70Ni致密度最高,可达99.6%,有助于强化其高温抗氧化性。对氧化膜进行扫描电镜(SEM)、能谱分析(EDS)以及X射线衍射(XRD)分析,系统地研究了TiN-Ni复合材料的高温氧化机理,分析表明氧化过程分为快速氧化过程和慢速氧化过程,其中存在金属离子的外扩散和氧离子的内扩散。

关键词:TiN-Ni金属陶瓷;高温氧化;Ni含量

Abstract:

Three kinds of TiN-Ni cermets containing Ni 30vol%, 50vol% and 70vol% were prepared by hot pressing sintering method. The continuous oxidation behavior of TiN-Ni cermet at 800 C in static air was studied. The results show that there is no chemical reaction between the TiN phase and the Ni phase during the sintering process, and the adjustment of Ni content contributes to the densification of sintering. The density of TiN/70Ni is the highest, up to 99.6%, which helps to strengthen its high temperature oxidation resistance. Scanning electron microscopy (SEM), energy spectrum analysis (EDS) and X ray diffraction (XRD) were used to study the mechanism of high temperature oxidation of TiN-Ni composites. The oxidation process was divided into rapid oxidation process and slow oxidation process, in which the external diffusion of metal ions and internal diffusion of oxygen ions existed.

Key words:TiN-Ni cermets; High-temperature oxidation resistance; Ni content