Strengthening of solid solution (Ti, La)(C, N)-based cermets by LaB6 addition. (February 2021)

• Record Type: Journal Article
• Authors: Wu, Xiaobo; Zhou, Shuzhu; Wu, Fengjing; Gao, Pingping; Lei, Ting; Xiao, Li; Liu, Chunxuan; Zhou, Haikun; Ouyang, Chun
• Is Part Of: International journal of refractory metals & hard materials. Volume 95(2021)
• Publication Date: 2021-02
• Subjects: (Ti, La)(C, N)-based cermets -- Solid solution -- Microstructure -- Carbonitriding; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2020.105443
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: (Ti, La)(C, N)-based solid solution cermets are fabricated from self-prepared (Ti, La)(C, N) carbonitrides by powder metallurgy with LaB6 addition in the solid solution. Based on the results of XRD and SEM analyses, it is confirmed that there is complete dissolution of (Ti, La)(C, N) powder. The presence of La can effectively suppress grain overgrowth and thus enhance the homogeneity of porcelain microstructure, consequently increasing the particle size of black phase. On the basis of equal mass fraction of La, the performance of (Ti, La)(C, N)-based cermets is better than that of Ti(C, N)-La-based cermets prepared by simple addition of LaB6 to Ti(C, N)-based cermet powder. The discrepancy can be directly related to the effect of adding LaB6 in the solid solution. The physical and mechanical properties of (Ti, La)(C, N)-based cermets comes to optimum when the content of dissolved La is 0.25 wt%, and there is hardness elevation of 20%. With suitable La addition, there is decrease of oxygen content in the solid solution of cermets. It is hence deduced that LaB6 can improve the performance of cermets as a deoxidizer. Highlights: Samples of (Ti, La)(C, N)-based solid solution cermets were fabricated by powder metallurgy method. The performance indexes of (Ti, La)(C, N)-based cermets are better than those of Ti(C, N)-La-based cermets with equal La mass fraction With the increase of La content, there is decline of oxygen content in the cermets solid solution. With the increase of La content, there is decline of oxygen content in the cermets solid solution. It is hence deduced that LaB6 functions as deoxidizer for the improvement of cermets quality.