Ti(C,N)基金属陶瓷成分对抗热震性能的影响

The effect of Ti(C,N)-Based Ceramic Composition on Thermal Shock Resistance

制备了不同碳氮比Ti(C,N)固溶体和分别加入NbC、TaC、VC、Cr_(3)C_(2)的Ti(C,N)基金属陶瓷,采用水淬冷热震方法研究了不同成分对Ti(C,N)基金属陶瓷抗热震性能的影响。结果表明:金属陶瓷在热冲击过程中,陶瓷相在热应力的作用下会发生开裂现象,在裂纹扩展路径上产生的微裂纹能促进裂纹扩展;在不同碳氮比的Ti(C_(x),N_(y))固溶体金属陶瓷中,碳氮比7/3的Ti(C_(0.7),N_(0.3))金属陶瓷的抗热震性能最好,本文研究中其热震临界温度为240℃;在添加的四种碳化物(NbC、TaC、VC和Cr_(3)C_(2))中,NbC和TaC能显著提升金属陶瓷的抗热震性,且TaC更优于NbC,而VC和Cr_(3)C_(2)的加入不利于改善金属陶瓷抗热冲击性能。

Ti(C,N)solid solutions with different carbon and nitrogen(C/N)ratios and Ti(C,N)-based ceramics with NbC,TaC,VC,and Cr_(3)C_(2)added separately were prepared.The effects of different compositions on the thermal shock resistance of Ti(C,N)-based ceramics were studied by means of water quenching.The results show that the ceramic phase cracks are observed under the action of thermal stress during the thermal shock process of the ceramics,and the microcracks in the crack propagation path can promote crack propagation.Among Ti(C_(x),N_(y))solid solution ceramics with different C/N ratios,Ti(C_(0.7),N_(0.3))ceramic with a C/N ratio of 7/3 has the best thermal shock resistance,and the critical thermal shock temperature is 240℃.Among the four added carbides(NbC,TaC,VC,and Cr_(3)C_(2)),the thermal shock resistance of the ceramics is significantly improved by NbC and TaC,and TaC is better than NbC,while the addition of VC and Cr_(3)C_(2)is not conducive to the thermal shock resistance of the ceramics.