《细晶粒TIC，N基金属陶瓷制备技术研究》由会员分享，可在线阅读，更多相关《细晶粒TIC，N基金属陶瓷制备技术研究（66页珍藏版）》请在金锄头文库上搜索。
1、南京航空航天大学硕士学位论文 i 摘摘 要要 本论文采用 X 射线衍射XRD扫描电镜SEM透射电镜TEMX 射线能谱 EDS电子探针 EPMA 等实验手段 系统研究了细晶粒 Ti(C,N)基金属陶瓷的成分制备工艺后处理工艺组织结构和性能等之间的关系 本文首先综述了近年来 Ti(C,N)基金属陶瓷的研究进展总结了 Ti(C,N)基金属陶瓷的制备技术成分及添加剂对 Ti(C,N)基金属陶瓷组织和性能的影响并简述了烧结理论的研究进展 研究了烧结温度以及纳米粉的加入量对金属陶瓷组织和性能的影响试验结果表明当纳米 TiCTiN 的含量分别为 TiCTiN 总量的 10时金属陶瓷具有相对较好的机械性能纳米
2、复合金属陶瓷的显微组织中没有明显 Rim相的小晶粒和具有白芯黑壳结构的小颗粒大大增加金属粘接相的体积分数也明显减少 部分小颗粒镶嵌于大颗粒的 Rim 相中 与之保持部分共格的关系这种较牢固的结合以及晶粒平均尺寸的减小是材料的强韧性得以增强的主要原因 研究了金属陶瓷氮化处理后表面组织结构和表面硬度的变化当金属陶瓷在 1200?常压 N2中处理时金属陶瓷表面形成了大约 15m 厚的富 N富Ti 的硬化层表面层晶粒明显细化表面硬化层中 Rim 相体积减少很多氮化处理可以较大的提高材料的表面硬度 计算了溶入不同含量 Mo 的(Ti1- x,Mox)(C0.8,N0.2)固溶体的价电子结构 结果表 明M
3、o 的 溶 入 使 该 相 塑 性 变 差计 算 了 溶 入 不 同 含 量 Cr 的(Ti0.9- x,Mo0.1,Crx)(C0.8,N0.2)固溶体的价电子结构结果表明当 x=0.15 时A C D En+最小该相塑性最好试验结果也证明了添加微量的 Cr3C2可以改善金属陶瓷环形相的塑性提高 Ti (C,N)基金属陶瓷的抗弯强度 关键词关键词 Ti(C,N)基金属陶瓷合金化制备技术表面氮化处理电子结构纳米复合材料 细晶粒 Ti(C,N)基金属陶瓷制备技术研究 ii Abstract The relationship among composition, manufacturing pro
4、cess, microstructure, post- treatment technique and properties of fine grained Ti(C,N)- based cermets has been researched by X- ray diffraction (XRD), scanning electron microscopy(SEM) and transmission electron microscopy (TEM), energy dispersive X- ray analysis(EDS), and electron- probe microanalys
5、is (EPMA). The research development of Ti(C,N)- based cermets over recent years has been systematically overviewed at first, which includes the influence of composition, additive, manufacturing process on the microstructures and properties of Ti(C,N)- based cermets. The influence of sintering temper
6、ature and addition of nano- structured powders on the microstructure and performance of cermets has been studied. When nano- structured TiC and TiN powders accounted for 10wt% of all the amount of TiC and TiN, better mechanical properties were possessed by the sintered cermets. It was found that the
7、 grains without obvious rim phase and those with white- cores and black- shell increased greatly, and the volume proportion of metal binder decreased obviously. Some small grains were also found to be embedded in the rim phase of big grains and kept partially coherent with it. This strong combinatio
8、n between them and the reduction of the average size of particles enhanced the obdurability of the produced cermets. The changes of the surface microstructure and the surface hardness in the cermets heat- treated in normal pressure nitrogen have also been studied. When the cermets were treated at 12
9、00?, a 15 mdeep surface, enriched N and Ti was produced. The particle size in the hardened surface became fine, and the volume fraction of rim phase reduced greatly. As a result, the surface hardness of the cermets was improved greatly after heat- treated in nitrogen. With different add contents of
10、Mo, the valence electron structure of the (Ti1- x,Mox)(C0.8,N0.2) carbonitrides was calculated. It was showed that the plasticity was reduced with the addition of Mo. With different add contents of Cr, the valence electron structure of (Ti0.9- x,Mo0.1,Crx)(C0.8,N0.2) carbonitrides was also calculate
11、d. When x=0.15, A C D En+was the smallest, and the plasticity of cermets was best. It has also been proved by the result of experiments that the plasticity of rim phase 南京航空航天大学硕士学位论文 iiiwas improved by subtle addition of Cr3C2. As a result, the transverse rupture strength of Ti (C,N)- based cermets
12、 was enhanced greatly. Keywords: Ti(C,N)- based cermets, alloying, manufacturing process, surface treatment in nitrogen, valence electron structure, nano- structured composite 南京航空航天大学硕士学位论文 iii图表清单 图清单图清单 图 1.1 Ti(C,N)基金属陶瓷显微结构 .12 图 2.1 试验中所用粉末的 SEM 形貌.15 图 2.2 纳米原始粉末的 TEM 形貌.15 图 2.3 试样压制压力与时间关系曲
13、线.16 图 2.4 金属陶瓷的真空烧结工艺及炉内真空度的变化曲线.17 图 2.5 三点弯曲法测试抗弯强度示意图.18 图 3.1 不同烧结温度下金属陶瓷的显微组织.20 图 3.2 烧结温度对 Ti(C,N)基金属陶瓷抗弯强度和硬度的影响 .22 图 3.3 不同纳米添加量的 Ti(C,N)基金属陶瓷显微组织.23 图 3.4 金属陶瓷在 1420下烧结显微组织.23 图 3.5 金属陶瓷最终烧结体环形相能谱析.24 图 3.6 纳米复合金属陶瓷的 TEM 明场像.25 图 3.7 纳米复合金属陶瓷中晶粒之间的界面取向关系.26 图 3.8 纳米粉添加量对 Ti(C,N)基金属陶瓷抗弯强度和硬度的影响.26 图 3.9 不同纳米粉添加量的金属陶瓷在 1430下烧结的断口形貌.28 图 4.1 未经氮化处理以及经过不同温度氮化处理下的金属陶瓷的显微组织.32 图 4.2 未经氮化处理的金属陶瓷主要合金元素的线分布.34 图 4.3 氮化处理后金属陶瓷主要合金元素的线分布.34 图 4.4 金属陶瓷氮化处理后的主要合金元素的面分布.
