SPS技术烧结制备钛铝碳陶瓷复合材料

发布时间：2018-01-15 16:33

本文关键词：SPS技术烧结制备钛铝碳陶瓷复合材料　出处：《中原工学院》2016年硕士论文　论文类型：学位论文

【摘要】：本论文利用放电等离子快速烧结新技术制备了一系列的钛铝碳陶瓷复合材料,然后采用热重分析仪、X-射线衍射仪、电子扫描电镜、固体密度仪、磨耗比测量仪和维氏硬度计等测试设备,对样品的物相结构、微观形貌、磨耗比和硬度等性能进行了相应的表征分析。主要的研究内容包括如下四个方面:(1)当cBN含量范围为10~40wt%,随着cBN含量的降低,合成复合材料的密度和硬度均增大。在烧结温度区间1200~1300℃,提高烧结温度制得复合材料的相对密度和硬度增大,微观形貌图表明cBN晶形完整且以镶嵌的方式存在于基体中;在烧结温度为1400℃时,cBN加剧软化且晶粒表面生成了较厚过渡层(AlN和TiB2),过渡层过厚会降低复合材料的力学性能;提高温度为1500℃时,复合材料的密度和硬度降低,微观形貌图表明cBN颗粒受到钛铝碳严重腐蚀且出现碎裂,导致复合材料的力学性能恶化。当cBN含量为10wt%时,在温度区间1200~1300℃和压力30MPa条件下,制得复合材料的力学性能优异,密度高达4.33g/cm3,硬度高达3000HV1,磨耗比为4.8。(2)在烧结温度1200℃和压力30MPa条件下,当金刚石含量为50~60wt%时,金刚石含量偏高导致复合材料中存在大量空洞,进而导致复合材料的密度和硬度降低。当金刚石含量为30wt%和40wt%时,复合材料具有较高的密度和硬度,且石墨化程度较低,提高烧结温度为1400℃,发现金刚石颗粒表面出现较厚的石墨层,金刚石的衍射峰减弱,且石墨衍射峰明显增强。提高温度为1500℃时,金刚石衍射峰消失,石墨衍射峰最强,微观形貌图中金刚石失去了规则晶体形状,复合材料的硬度和密度降为最低。在烧结温度为1100~1200℃和压力30MPa条件下,当金刚石含量为40wt%时,制得样品中金刚石石墨化程度较低且晶形完整,金刚石颗粒被完全包覆,样品密度约3.73g/cm3,磨耗比高达1550。(3)将二硼化钛和钛铝碳微粉混合均匀后,在烧结温度区间1200~1600℃和压力30~70MPa条件下制得二硼化钛/钛铝碳陶瓷复合材料。结果发现在压力30MPa条件下,添加二硼化钛含量为70~90wt%时,制得的陶瓷复合材料的微观形貌中存在较多空洞,密度偏低,硬度低于670HV1;当添加的二硼化钛含量为60wt%时,在烧结温度1200℃条件下制得复合材料的微观结构中空洞数量降低且空径变小,硬度高达1070HV1;当烧结温度为1600℃时,制得复合材料60TiB2的微观形貌中空洞消失,密度高达4.39g/cm3,硬度约2300HV1,磨耗比约1.1。(4)采用氧化铝和钛铝碳微粉为原料制备氧化铝/钛铝碳陶瓷复合材料,结果发现降低Al_2O_3的含量,复合材料的密度增大。当制得复合材料的密度小于3.84g/cm3时,样品均表现为硬度偏低且微观形貌致密性较差;当Al_2O_3含量为60wt%时,在低温1100℃就可以得到较高的密度和硬度,复合材材料60Al_2O_3的微观结构致密,但仍存在微量的空洞;提高烧结温度为1400℃和50MPa条件下,制得复合材料60Al_2O_3的微观结构的致密度提高,空洞消失,钛铝碳完全分解为碳化钛,氧化铝以镶嵌在碳化钛基体中,使得复合材料60Al_2O_3具有较高的硬度、密度和磨耗比,密度约4.45g/cm3,硬度约1800HV1,磨耗比高达0.95。
[Abstract]:The titanium aluminum carbon ceramic composite material prepare a series of new technology prepared by spark plasma sintering, then using thermogravimetric analyzer, X- ray diffraction, scanning electron microscopy, solid density instrument, wear ratio measuring instrument and Vivtorinox hardness testing equipment, the microscopic morphology of the samples, phase structure, wear ratio and hardness properties were analyzed and corresponding characterization. The main research contents include four aspects as follows: (1) when the cBN content is in the range of 10~40wt%, with the decrease of cBN content, the density and hardness of composite materials increased. In the sintering temperature range of 1200~1300 DEG C, higher sintering temperature was relative density and hardness the composites increases and the micrograph shows that cBN crystal and in the form of inlay in the matrix; the sintering temperature is 1400 degrees centigrade, cBN increased and the grain surface softening forming thick transition layer (AlN and TiB 2), the transition layer is too thick will reduce the mechanical properties of composite materials; improve the temperature is 1500 degrees centigrade, the density of the composites and the hardness decreased, morphology shows that cBN particles by titaniumaluminumcarbon serious corrosion and fragmentation, resulting in deterioration of the mechanical properties of the composites. When the cBN content is 10wt%, in the range of temperature 1200~1300 C and 30MPa pressure conditions, the mechanical properties of the composites prepared excellent density up to 4.33g/cm3, 3000HV1 hardness, wear ratio of 4.8. (2) in the sintering temperature of 1200 DEG C and the pressure under the condition of 30MPa, when the diamond content is 50~60wt%, resulting in a high diamond content in composite materials there are many holes, and then the resulting composite material density and hardness decreased. When the diamond content is 30wt% and 40wt%, the composite material has high density and hardness, and the graphitization degree is low, increasing the sintering temperature of 1400 DEG C, found a diamond The particle appears on the surface of graphite layer thick, diamond diffraction peaks decreased, and the diffraction peaks of graphite increased obviously. Increasing the temperature is 1500 degrees centigrade, diamond graphite peaks disappeared, the strongest diffraction peaks, diamond morphology diagram lost the regular crystal shape, hardness and density of composites decreased to the lowest in the sintering temperature is. 1100~1200 temperature and pressure 30MPa condition, when the diamond content is 40wt%, the sample prepared in low degree of graphitization of diamond and crystalline diamond particles were coated completely, the density of the sample is about 3.73g/cm3, the wear ratio up to 1550. (3) of the titanium diboride and titanium aluminum carbon powder mixed evenly, made of titanium / titanium diboride aluminum carbon ceramic composite materials in the sintering temperature range of 1200~1600 DEG C and pressure under the condition of 30~70MPa. The results showed that under the pressure of 30MPa, adding TiB2 content is 70~90wt%, the ceramic composite material prepared by the There are more empty, the low density of microstructure, hardness is lower than 670HV1; when the 60wt% content of TiB2 added, the number of empty prepared microstructures of composites decreased and the empty size is smaller in the sintering temperature under 1200 DEG C, hardness up to 1070HV1; when the sintering temperature is 1600 degrees centigrade for micro the morphology of 60TiB2 in the composite cavity disappeared, density of up to 4.39g/cm3, the hardness of about 2300HV1, the wear rate is about 1.1. (4) preparation of alumina / titanium aluminum carbon ceramic composite materials were prepared using alumina and titanium aluminum carbon powder, the lower the content of Al_2O_3, the density of the composite increases. When the density of the composites prepared less than 3.84g/cm3, the samples showed lower hardness and microstructure compactness is poor; when the Al_2O_3 content is 60wt%, in the low temperature 1100 DEG C can be high density and hardness, micro composite material 60Al_2O_3 Compact structure, but there are still traces of void; improve the sintering temperature of 1400 DEG C and 50MPa, prepared microstructure of 60Al_2O_3 composite density increase, cavities disappeared completely decomposed into titanium aluminum carbon, titanium carbide, titanium carbide in the alumina matrix to inlay, made of composite materials 60Al_2O_3 have higher hardness. The density and wear ratio, density of about 4.45g/cm3, the hardness of about 1800HV1, the wear ratio up to 0.95.

【学位授予单位】：中原工学院
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ174.758.2

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