共查询到19条相似文献,搜索用时 203 毫秒
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介绍了Ti(C,N)基金属陶瓷的性能,主要综述了Ti(C,N)基金属陶瓷在高速刀具的应用和制备工艺的基本原理。着重讨论了各种烧结工艺的优缺点,并展望了Ti(C,N)基金属陶瓷未来的发展方向。 相似文献
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用粉末冶金真空烧结法制备了超细晶粒碳氮化钛[Ti(C,N)]基金属陶瓷.研究了原始粉末粒径对Ti(C,N)基金属陶瓷微观结构和力学性能的影响.结果表明:在化学成分相同的条件下,晶粒细化使材料的Vickers硬度和抗弯强度上升,但断裂韧性有所下降.在超细晶粒Ti(C,N)基金属陶瓷微观组织中出现了一种新型的白芯/灰壳结构和一种特殊化合物(Ni2Mo2.5W1.3)Cx.初步研究表明:由于原始粉末粒径微小,促进了扩散反应因而生成了这种芯/壳结构.芯/壳结构有利于提高材料的抗弯强度和断裂韧性.(Ni2Mo2.5W1.3)Cx有利于提高材料的Vickers硬度,但是降低了Ti(C,N)基金属陶瓷的抗弯强度和断裂韧性. 相似文献
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Ti(C,N)基金属陶瓷氮化处理后的表面组织结构及形成机理 总被引:15,自引:1,他引:15
对Ti(C,N)基金属陶瓷进行了表面氮化处理。用SEM,EPMA,TEM/EDX分析了材料表面显微组织的特征。研究发现,材料表面形成了富N、富Ti的相,它们包覆在硬质颗粒的表面。硬质颗粒周围的环形相的体积分数大大减少。晶粒尺寸也明显减小。紧邻表面硬化层,出现了一层金属粘接相含量较高的过渡层。表面氮化处理使Ti(C,N)基金属陶瓷的表面硬度得到明显的提高,而基本上不影响其抗弯强度。表面较高的-N的活度是促使各合金元素扩散,形成上述特征组织的驱动力。 相似文献
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Ti(C,N)基金属陶瓷作为一种新型的工具材料,具有密度低、室温硬度和高温硬度都优于WC基硬质合金、化学稳定性和抗氧化性好、耐磨性好等优点。介绍了Ti(C,N)基金属陶瓷的基本组成和结构,组织性能及其影响因素,综述了Ti(C,N)基金属陶瓷的研究现状,指出了其未来的发展方向和应用。 相似文献
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《中国陶瓷》2019,(2)
以Ti/Si/C,Ti/SiC/C和Ti/Si/TiC粉为原料体系,采用真空热压烧结制备纯样Ti_3SiC_2,通过XRD和SEM研究了不同原料体系和烧结温度对试样相组成、致密度及显微结构的影响。研究表明:烧结温度为1550℃时,Ti/Si/TiC体系制备的纯样Ti_3SiC_2主晶相为Ti_3SiC_2,第二相为TiC,Ti_3SiC_2相含量为94%,为各试样中最高,Ti_3SiC_2材料较其他试样致密且Ti_3SiC_2晶粒发育成均匀良好的板状晶粒,粒径约为20μm;制备纯度较高的Ti_3SiC_2材料需要提高Ti/Si/C,Ti/SiC/C原料体系的烧结温度。 相似文献
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Ti(C,N)对刚玉质浇注料性能的影响 总被引:2,自引:0,他引:2
骨料采用电熔白刚玉,基质采用白刚玉细粉、活性α-Al2O3微粉、SiO2微粉及Ti(C,N)微粉,按骨料与基质质量比为70:30,α-Al2O3微粉和Ti(C,N)微粉总质量分数固定为10%,制备了Ti(C,N)含量(质量分数)分别为0、5%和10%的三种刚玉质浇注料,对比了三种材料的常温物理性能、抗碱(K2O)性能及抗渣性能,并借助XRD和光学显微镜研究了材料的物相组成和显微结构。结果表明:加入Ti(C,N)后,刚玉质浇注料经1500℃3h热处理后强度显著增大,抗碱(K2O)性能及抗渣性能随Ti(C,N)加入量的增加而逐渐提高。其主要机理为:Ti(C,N)促进了材料的高温烧结,改善了材料的显微结构;同时Ti(C,N)化学稳定性优良,难于被熔渣润湿,材料基质中均匀分散的Ti(C,N)减弱了碱(K2O)及熔渣对刚玉质浇注料的渗透和侵蚀。 相似文献
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Two series of Ti (C, N)-based cermets, one with TiC addition and the other with TiN addition, were fabricated by conventional powder metallurgy technique. The initial powder particle size of the main hard phase components (Ti (C, N), TiC and TiN) was nano/submicron-sized, in order to achieve an ultra-fine grade final microstructure. The TiC and TiN addition can improve the mechanical properties of Ti (C, N)-based cermets to some degree. Ultra-fine grade Ti (C, N)-based cermets present a typical core/rim (black core and grayish rim) as well as a new kind of bright core and grayish rim structure. The average metallic constituent of this bright core is determined to be 62 at% Ti, 25 at% Mo, and 13 at% W by SEM–EDX. The bright core structure is believed to be formed during the solid state sintering stage, as extremely small Ti (C, N)/TiC/TiN particles are completely consumed by surrounding large WC and Mo2C particles. Low carbon activity in the binder phase will result in the formation (Ni2Mo2W)Cx intermetallic phase, and the presence of this phase plays a very important role in determining the mechanical properties of TiN addition cermets. 相似文献
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Songlan Yang Zheng Ming Sun Hitoshi Hashimoto Toshihiko Abe 《Journal of the European Ceramic Society》2003,23(16):3147-3152
In this study, free 2Ti/2Si/3TiC powder mixture was heated at high temperatures in vacuum, in order to reveal the possibility for the synthesis of high Ti3SiC2 content powder. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for the evaluation of phase identities and the morphology of the powder after different treatments. Results showed that almost single phase Ti3SiC2 powder (99.3 wt.%) can be synthesized by heat treatment with free 2Ti/2Si/3TiC powders in vacuum at 1210°C for about 3 h. The nucleation and growth of Ti3SiC2 within TiC particles was observed. The typical appearance of the formed Ti3SiC2 is equiaxed with particle size of 2–4 μm. Effects of temperature and heating time on the morphology and the particle sizes of the synthesized Ti3SiC2 powders are not obvious. 相似文献
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原位燃烧合成Si3N4/Ti(C,N)/SiC复相陶瓷热力学分析 总被引:3,自引:0,他引:3
研究了用TiC作添加剂时Si粉坯在高压氮气中的燃烧行为,结果表明:TiC加入量对燃烧合成产物的相组成有重要影响,原因在于TiC加入量直接影响燃烧过程中氮气向反应前沿的渗透性,从而影响试样中不同部位氮气分压的变化,适当调整工艺参数,可以合成Si3N4/Ti(C,N)/SiC复相陶瓷,并从热力学角度对实验结果进行了合理的解释。 相似文献
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《应用陶瓷进展》2013,112(5):247-254
AbstractEffect of the particle size of TiC and TiN on the microstructure and mechanical properties of Ti(C,N) based cermets has been evaluated. Ti(C,N)–WC–Co cermets made from four groups of mixed raw powders of different sizes were manufactured by vacuum sintering. The microstructure and composition were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDX). The result shows that the four samples have the typical microstructures of 'black core/grey rim'. The mechanical properties of the cermet manufactured from submicron TiC and nano TiN are the best among the four samples. 相似文献
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《Ceramics International》2018,44(18):22538-22548
In order to enhance the wear resistance of Fe-based cladding layer, TiN, Ti and graphite were added into Fe313 powder and in-situ formation of Ti(C, N) ceramic reinforcement phase was carried out by laser cladding. Firstly, thermodynamic calculations were used to determine the feasibility and favorability of a chemical reaction. Then, the reaction mechanism was investigated by adding five groups of different contents and carrying out EDS and phase analysis. We report that large TiN particles do not completely decompose and in-situ synthesized TiC phase forms around large TiN particles. However, small TiN particles are completely decomposed and directly formed the Ti(C, N) phase. Finally, through the friction and wear tests, it has been observed that the friction coefficient of a sample, with three powders added, was 0.559 times smaller than the substrate and 0.725 times smaller than the initial powder, and the wear volume of the same sample was 0.365 times smaller than the substrate and 0.799 times smaller than the initial powder. Therefore, it can be concluded that the in-situ synthesis of Ti(C, N) ceramic reinforced Fe-based coatings by laser cladding greatly improves the wear resistance of the Fe313 layer. 相似文献
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Preparation of a titanium carbide coating on carbon fibre using a molten salt method 总被引:1,自引:0,他引:1
A method for preparing protective titanium carbide (TiC) coatings on carbon fibres has been developed using a molten salt synthesis method. The TiC coatings were formed on the surface of carbon fibres in a reaction medium consisting of Ti powder in a mixture of molten LiCl-KCl-KF salts under an argon atmosphere at 900 and 950 °C. The structure and morphology of the TiC coatings were characterized by XRD, SEM and energy dispersive X-ray (EDX) analyses. The coatings consisted of homogeneous single phase cubic TiC with thicknesses in the range of 60-800 nm. Variation of the synthesis time and reaction mixture was found to significantly affect the thickness and integrity of the TiC coating although variation of the reaction temperature had little effect. The coating thickness was closely related to the composition of the molten salts and to the molar ratio between the carbon fibre and titanium. 相似文献
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Huihua Wang Wenyuan Wu Shucheng Sun Xue Bian Ganfeng Tu 《Ceramics International》2011,37(7):2689-2693
TiB2/TiC nanocomposite powders were successfully prepared by high-energy ball milling of the powder mixtures of Ti and B4C. X-ray diffraction analysis showed that the TiC phase was not produced until the milling time was up to 24 h and only a minimal amount of TiB2 was generated, even after 48 h of milling. The critical grain size of Ti milled for the reaction between Ti and B4C was 31.2 nm. Transmission electron microscopy clearly indicated that the resulting powder mixture obtained after milling for 48 h and annealing at 800 °C for 30 min was composed of nanosized TiC and TiB2 particles. 相似文献
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An attempt was made to lower the ductile-to-brittle transition temperature (DBTT) of polycrystalline TiC and to prevent the premature intergranular fracture noted in stoichiometric Tic at high temperatures by producing four substoichiometric compositions chosen from the single-phase TiC phase field. Each desired composition was prepared by blending and vacuum hot-pressing the appropriate mixture of Ti powder and stoichiometric TiC powder. Each billet was characterized for density, hardness, lattice parameter, and microstructure. The actual bulk compositions were determined by averaging electron probe microanalysis data collected randomly from a polished section of each billet. Specimens cut from the billets were strength-tested in four-point bending from room temperature to 1400°C and in compression from room temperature to 1200°C. A qualitative determination of the material's ductility was obtained from a load vs deflection plot and by optical microscopy of polished surfaces after deformation. Both the hardness and strength dropped with decreasing C/Ti atom ratios. Billets produced at the lower C/Ti atom ratios showed a significant deviation from linearity of the load/ deflection curve at temperatures as low as 1200°C in bending, with little or no drop in strength, and as low as 600°C in compression. 相似文献
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Ti_3AlC_2陶瓷的热压合成 总被引:1,自引:0,他引:1
以TiC-Ti-Al为反应体系,采用原位热压技术制备Ti3AlC2陶瓷。借助XRD分析相组成,并对实验现象进行分析。结果表明,TiC的加入,避免了Ti和C粉之间强烈的放热反应。通过降低初始压坯尺寸抑制了"热爆行为",有利于合成高纯Ti3AlC2。用大压坯时,"热爆行为"明显,产物由Ti3AlC2、TiC和Ti3Al相组成,Ti3AlC2含量少;用小压坯时,未发生"热爆行为",产物由Ti3AlC2和TiC相组成,Ti3AlC2相含量较高。 相似文献