渗硼对Ti(C,N)基金属陶瓷抗热震性能的影响  

Effect of Boronizing on Thermal Shock Resistance of Ti(C,N) -based Cermet

作　　者：詹斌[1] 刘宁[1] 李彬彬[1] 唐慧兰[1] 刘爱军[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《热处理》2012年第4期22-28,共7页Heat Treatment

基　　金：安徽省自然科学基金项目(090414185)

摘　　要：采用粉末冶金法制备了Ti(C,N)基金属陶瓷,并对其进行了固体渗硼。研究了渗硼后金属陶瓷的显微组织和力学性能以及渗硼对抗热震性能的影响。结果表明,Ti(C,N)基金属陶瓷的渗硼层由硼化物层、扩散层和基体区组成;渗硼使金属陶瓷的表面硬度提高,抗弯强度降低,使导致金属陶瓷热震残留强度急剧下降的临界热震温差降低约100℃;渗硼使Ti(C,N)基金属陶瓷热震后的残留强度降低,主要是分布不均和形状不规则的孔洞所致;当热震温差较小时,渗硼使金属陶瓷表面萌生热震裂纹的孕育期延长,从而推迟了主裂纹的形成;而热震温差较大时,经渗硼的金属陶瓷热震裂纹扩展较快,易形成龟裂。Ti （ C, N） -based cermet was prepared by powder metallurgic method, and then was pack boronized. The microstructure, mechanical properties and the effect of boronizing on thermal shock resistance were studied with regard to boronized Ti（ C, N） -based cermet. The results show that ： （a） the boronized layer of Ti （ C, N） -based cermet consists of boride layer, diffusion layer and substrate zone ; （b） boronizing makes Ti（ C, N） -based cermet increase in surface hardness , decrease in bending strength and decrease in critical thermal shock temperaturedifference which results in sharp reduction in the residual strength after thermal shock by about 100 ~ ; （ c ） boronizing makes Ti（ C, N）-based cermet decrease in the residual strength after thermal shock , which is mainly attributed to non-uniformly distributed and irregularly shaped voids; （d） in case the thermal shock temperature difference is small, the incubation period of thermal shock crack initiation at the cermet surface will be prolonged due to boronizing, and therefore formation of main crack will be delayed; in reverse, the thermal shock crack will faster propagate , and be easy to become an alligator-hide crack in the boronized cermet.

关 键 词：Ti(C  N)基金属陶瓷 渗硼 抗热震性能 

分 类 号：TG148[一般工业技术—材料科学与工程]