N含量对Ti(C,N)基金属陶瓷微观组织结构和性能的影响  

Effects of N Content on the Microstructure and Properties of Ti(C,N)-Based Cermets

作　　者：罗双兰 刘钢 陈信锗 颜练武 何世文[1] 周伟[1] 彭英彪[1] LUO Shuanglan;LIU Gang;CHEN Xinzhe;YAN Lianwu;HE Shiwen;ZHOU Wei;PENG Yingbiao(National&Local Joint Engineering Research Center for Advanced Packaging Material and Technology,Hunan University of Technology,Zhuzhou Hunan 412007,China;OKE Precision Cutting Tools Co.,LTD.,Zhuzhou Hunan 412007,China)

机构地区：[1]湖南工业大学先进包装材料研发技术国家地方联合工程研究中心,湖南株洲412007 [2]株洲欧科亿数控精密刀具股份有限公司,湖南株洲412007

出　　处：《湖南工业大学学报》2023年第5期60-67,77,共9页Journal of Hunan University of Technology

基　　金：湖南省教育厅科研基金资助项目(21B0542);湖南省自然科学基金资助项目(2023JJ50182,2022JJ50086,2020JJ6069)。

摘　　要：针对Ti(C, N)基金属陶瓷在烧结过程中存在明显脱氮行为的问题,采用氮分压烧结方法是实现微观组织结构可控和获得优异性能的关键之一。制备了3种不同氮含量的Ti(C, N)基金属陶瓷,研究了氮含量和烧结温度对合金芯部和表面梯度层微观组织结构和性能的影响。结果表明:随着氮含量增加,合金芯部Ti(C,N)黑芯数量越多,黑芯外环的厚度越薄,同时硬质相晶粒越细;随着烧结温度升高,样品氮分解压力逐渐增大,由开始的渗氮现象转变为脱氮现象。当烧结温度为1 470℃时,合金表面发生了渗氮反应,形成一层无环黑芯聚集层,且其厚度随着合金氮含量的增加而减少;当烧结温度增加至1 530℃时,合金表面发生了脱氮反应,形成了一层灰色固溶体层,且随着合金中氮含量的增加,脱氮反应加剧,固溶体层厚度也越厚。研究发现,在1 470℃和0.8 kPa氮分压下烧结的样品,为含氮量最高的合金,具有最薄的黑芯聚集层和最细的硬质相晶粒,表现出较佳的综合性能。In view of the obvious denitrification phenomenon of Ti(C,N)-based cermets in the process of sintering,nitrogen partial pressure sintering method has been adopted as one of the keys to achieving a controllable microstructure with an optimized performance.Three Ti(C,N)-based cermets are prepared with different nitrogen contents,followed by a study on the effects of nitrogen content and sintering temperature on the microstructure and properties of the alloy core and surface gradient layers.The results show that as the nitrogen content increases,the number of Ti(C,N)black cores in the alloy core increases as well,the thinner the thickness of the outer rim of the black core,the finer the hard phase grains will be.The nitrogen decomposition pressure of the sample gradually increases correspondently with an increase in the sintering temperature,transforming from an initial nitriding process to a subsequent denitrification phenomenon.At a sintering temperature of 1470℃,nitriding reaction occurs on the surface of the alloy,forming a rimless black core aggregation layer on the surface,its thickness decreasing with the increase of nitrogen content of the alloy.When the sintering temperature reaches 1530℃,denitrification reaction occurs on the surface of the alloy,forming a layer of gray solid solution.With the increase of alloy nitrogen content,the more intense the denitrification reaction,the thicker the solid solution layer will be.It is found that the alloy with the highest nitrogen content has the the thinnest black core aggregation layer and the finest hard phase grains in the samples sintered at 1470℃and 0.8 kPa nitrogen partial pressure,exhibiting a better comprehensive performance.

关 键 词：氮含量 TI(C N)基金属陶瓷 微观组织结构 表面梯度层 力学性能 

分 类 号：TG148[一般工业技术—材料科学与工程]