【作者】 王小梅；

【导师】 熊惟皓；

【作者基本信息】 华中科技大学 ， 材料学， 2009， 硕士

【摘要】 本文对金属陶瓷特别是Ti(C,N)基金属陶瓷的研究进展进行了综述,主要研究了粘结相中加入Hastelloy X合金粉(HXP)对材料组织和氧化性的影响,制备了成分为32%(Ni+HXP)-36.5%TiC-10%TiN-12.5%Mo-7.2%WC-1%Cr3C2-0.8%C的金属陶瓷,采用金相显微镜(OM)、X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)等手段、三点弯曲和高温氧化实验,探讨了Ti(C,N)基金属陶瓷微观组织及氧化膜的微观特性、力学性能和高温抗氧化性能。每种成分的Ti(C,N)基金属陶瓷的致密度和抗弯强度规律大体一致,都随烧结工艺的不同呈显出先增大后减小的趋势,且二者的最大值均在最佳烧结温度处,HXP含量为5﹪的材料致密度最大值接近98﹪,高于不添加HXP的材料致密度最大值,且前者的抗弯最大值接近于2000MPa,高于后者的最高抗弯1848 MPa,而其它成分材料两性能最大值均低于此值并随着HXP含量的增高依次降低;HXP含量的多少对Ti(C,N)基金属陶瓷材料的硬度影响并不大,一般在89.5-90.5HRA之间。添加HXP的Ti(C,N)基金属陶瓷中出现了Ni-Cr-Fe固溶体,且固溶体生成量及其成分随着HXP的添加量的增加略有不同。每种成分的Ti(C,N)基金属陶瓷基本上都能形成芯-环结构,而且大部分芯-环结构都具有过渡层rim相。含有0-16% HXP的材料组织结构属于正常的金属陶瓷组织,其中含有5% HXP和0% HXP的材料几乎所有的相为完整的芯-环结构,且rim相的厚度略小于0.5μm,前者的组织分布比后者均匀;HXP的含量为22%时,材料的部分组织结构不完整,且rim相的厚度很多都超过了0.5μm;HXP的量为32%时,材料表面有很多孔洞,致密度低,组织结构大部分都不完整且分布不均匀。Ti(C,N)基金属陶瓷材料氧化膜生长速度遵守抛物线定律。对氧化增重数据进行动力学方程模拟,当粘结相中HXP的含量为0%-10%时,氧化膜比较致密,高温抗氧化能力较好,其中HXP的含量为5%时材料氧化膜比不含HXP的材料氧化膜致密化程度好,加之前者比后者的烧结致密度大,所以前都比后者的高温抗氧化性好;当HXP的含量超过16%时,生成的氧化膜比较疏松,材料高温抗氧化能力低。Ti(C,N)基金属陶瓷的高温抗氧化性应是随着HXP的含量的增加而提高的,但HXP的含量高时,材料的致密度低,材料的高温抗氧化性低。综合分析知HXP的含量为5%左右时,Ti(C,N)基金属陶瓷材料高温抗氧化性最好。更多还原

【Abstract】 In this paper, Cermets especially Ti (C, N)-based cermets were reviewed, mainly study the effects of Hastelloy X powder (HXP) on the microstructure and oxidation of Ti (C, N)-based cermets, whose components is 32 % (Ni + HXP) -36.5% TiC-10% TiN-12.5% Mo-7.2% WC-1% Cr3C2-0.8% C. Use the optical microscope (OM), X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and so on, three-point bending tests and high-temperature oxidation experiments to study the microcharacteristics and the microstructure of oxide film, mechanical properties and high temperature oxidation resistance of Ti (C, N)-based cermets.Both the relative density and the bending strength of Ti (C, N) -based cermets which have the same law follow parabolic law in line with the sintering temperature, and the two kinds of peaks are both at the best sintering temperature. The relative density of cermets with 5% HXP close to 98%, higher than that of cermets with 0% HXP, and the maximum bending strength of the former is closer to 2000MPa, which is higher than that of the latter, whose is 1848MPa, while the other cermets are lower, and the higher content of HXP, the lower peaks; The effect of HXP on hardness of Ti (C, N)-based cermets which are between 89.5-90.5HRA is not obvious.Ni-Cr-Fe solid solutions were found in the Ti (C, N)-based cermets with HXP, and the solid solution and its components are slightly different with the addition of HXP increase. All the Ti (C, N)-based cermets can basically form a core-shell structure, and most of the core-shell structures have the rim-phase. The microstructure of the Ti (C, N)-based cermets containing 0-16% HXP belong to the classical ceramic structure. The cermets containing 5% HXP and 0% HXP are almost with complete core-shell structure, and the thickness of rim-phase is slightly less than 0.5μm. Part of the microstructures of Ti (C, N)-based cermets contenting of 22% HXP are incomplete, and the thickness of a lot of the rim are more than 0.5μm. For 32% HXP, there are many holes in the material surface, and most of the microstructure is not complete and uneven.Oxide film growth rate of Ti (C, N)-based cermets follow the parabolic law. The kinetic equations of oxidation weight gain of were simulated. when the cermets content of 0% -10% HXP, the oxide films are relatively dense, a good high-temperature anti-oxidation, and while the oxide film of materials which content 5%HXP is more dense than non-HXP material, and combined with that the relative density of the former is higher than the latter, so the high-temperature oxidation resistance of the former is better than the latter; when Ti (C, N)-based cermets content more than 16% HXP, the oxide films are porous reducing the high-temperature antioxidant capacity.The high-temperature oxidation resistance of Ti (C, N)-based cermets should be increases with HXP, but the relative density of the high content of HXP was very low, which greatly reduces the high-temperature oxidation resistance. The high-temperature oxidation resistance of Ti (C, N)-based cermets which are contents of 5% HXP are the best by comprehensive analysis.更多还原