共查询到19条相似文献,搜索用时 125 毫秒
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利用钛铁矿铝热碳热原位还原技术成功制备了Al2O3-TiC增强铁基复合材料。通过XRD,SEM和力学性能检测方法分析了钛铁矿原位合成和添加合成两种方式对Al2O3-TiC增强铁基复合材料的组织和力学性能的影响。结果表明:利用钛铁矿合成的铁基复合材料的增强相为Al2O3,MgAl2O4,TiC和Fe相,添加合成过程中会发生一些硬质相TiC被氧化的现象。钛铁矿原位合成Al2O3-TiC增强铁基复合材料的基体组织呈粗大的块条状分布;添加合成的复合材料的铁基体以块状均匀分布。制备的Al2O3-TiC增强铁基复合材料的性能比较优良。材料的最佳综合力学性能为抗弯强度937MPa,维氏硬度532。 相似文献
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评述了近年来对TiB2-金属陶瓷及其原位合成技术的研究进展。从其烧结工艺、显微结构及其在涂层中的原位合成制备技术等方面进行了分析和讨论。指出了目前限制TiB2-金属陶瓷广泛应用的主要问题:原料价格昂贵、烧结工艺复杂、难以致密化,同时,涂层的力学性能有待进一步提高,并提出了解决上述问题的可行途径。 相似文献
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通过自蔓延高温合成结合准热等静压法(SHS/PH IP) 制备出了致密的TiC2Al2O3-20Fe 金属陶瓷。研究了延迟时间、高压持续时间、压力等工艺参数对金属陶瓷密实度的影响, 分析了金属陶瓷的相组成、微观组织及性能。结果表明, 燃烧合成过程中气体的排放和液相的存在是合成密实材料的关键, 通过优化工艺合成了密实度为97. 7% 的TiC2Al2O3-20Fe 金属陶瓷。金属陶瓷由TiC、Al2O3 和Fe 粘结相组成。粘结相Fe 与Al2O3 之间界面光滑,Fe 与T iC 之间有一较薄扩散层。TiC2Al2O3-20Fe 金属陶瓷的抗弯强度和抗压强度分别为890M Pa 和18. 4 GPa。 相似文献
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SHS/PHIP技术制备TiC—30Fe金属陶瓷的显微组织及形成过程研究 总被引:5,自引:1,他引:4
通过自蔓延高温合成结合准热等静压法制备出了致密度为96.3%的TiC-30wt%Fe金属陶瓷。分析了金属陶瓷的结构和组织,讨论了SHS/PHIP制备金属陶瓷的材料结构形成过程。结果表明,金属陶瓷由近乎球形TiC颗粒和Fe粘结相组成。粘结相Fe与TiC之间有一较薄扩散层。 相似文献
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Al—TiO2自蔓延高温合成和热爆合成金属陶瓷宏观动力学差异 总被引:1,自引:0,他引:1
通过试验观察了Al-TiO_2自蔓延高温合成(SHS)和热爆合成Ti-Al_2O_3金属陶瓷复合材料宏观结构差异,并结合冶金学原理对此作了分析。发现Al-TiO_2反应系统以SHS方式进行时,能合成组成、结构均匀的Ti-Al_2O_3金属陶瓷复合材料,而热爆方式进行时则不能做到。 相似文献
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利用钒钛铁精矿中的铁和钛元素,以钒钛铁精矿、石墨为主要原料,按铁基摩擦材料的成分添加其他组份,采用原位合成技术,实现合成与烧结一体化,制备铁基摩擦材料。对钒钛铁精矿还原过程中的热力学进行计算和分析,利用TG–DSC检测方法对还原过程中的质量变化进行分析。结果表明:当温度高于979 K时,钒钛铁精矿中Fe氧化物和Ti氧化物相继发生还原反应,其还原过程为:首先Fe3O4被还原,其次是钛磁铁矿和钛铁矿发生反应生成Fe和Ti的氧化物,最后是Ti的各阶氧化物反应生成TiC。本实验根据分析结果,制定了合理的工艺路线,获得了组织致密,结合优良的铁基摩擦材料。 相似文献
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Annie George V. S. Kelukutty L. G. Radhika P. N. Mohandas P. K. Rohatgi 《Journal of Materials Science》1984,19(5):1522-1529
Rutile, the raw material needed for chloride route has to be prepared by removing iron from ilmenite, as rutile deposits are scarce in nature. In this study, the iron oxide present in ilmenite was reduced for different times and temperatures using coconut pith which is an agrowaste available in large quantities in Kerala. Pith has lowS, P and ash contents and has a moderate calorific value. The reduction process was studied using chemical analysis, SEM, X-ray and EPMA. Reduction of iron oxide in the ilmenite reaches a maximum at 3 to 4 h at 1040°C containing 84% of iron in the metallic state and the rest in the ferrous state. Treatment with 20% hydrochloric acid at 80°C for 1 h with stirring, leaches out most of the iron from the reduced ilmenite leaving behind only 2% iron. The SEM and X-ray data show the gradual reduction and structural changes taking place during reduction of ilmenite with coconut pith. 相似文献
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N. J. Welham 《Journal of Materials Science》2001,36(9):2343-2348
The generally accepted method for recovering oxygen on an extraterrestrial body is by thermal reduction of indigenous minerals, the most amenable of which is ilmenite, FeTiO3. Thermodynamic modelling shows that carbon is a more effective reductant than hydrogen. In this paper the effect of extended ball milling on the carbothermic reduction of a terrestrial beach sand derived ilmenite is examined. The rate of oxygen recovery into the gas phase is substantially faster for powders milled together and a concomitent lowering of onset temperature is also noted. XRD examination of the final powders indicate that reduction of ilmenite proceeds via elemental iron and rutile which is then further reduced to sub-oxides. The presence of nitrogen, or excess carbon, leads to vastly greater oxygen recovery due to the formation of titanium nitride or carbide with complete release of oxygen from the mineral achieved in 1 h at 1200°C. 相似文献
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利用微波等离子体技术,在氢气和甲烷的气氛中,对钛铁矿进行了还原。通过XRD和SEM分析了不同的甲烷流量及微波功率对还原产物的组成及形貌的影响。研究结果表明,反应气体中碳浓度的增加或微波功率的提高,有利于纳米碳管的生长,并加快钛铁矿的还原速率。 相似文献
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XiangChun Liu Rongzi Hong Changsheng Tian 《Journal of Materials Science: Materials in Electronics》2009,20(4):323-327
The tolerance factor of ABO3-type ilmenite by analyzing the ABO3 ilmenite crystal structure is established. Combining with the electronegativity difference and octahedral factor of ABO3 structure, regularities governing the formation and the stability of ilmenite-type compounds are discussed. The tolerance
factor equation was proved appropriate for ilmenite structure by analyzing the structure stability of some ilmenite compounds.
According to the results of statistically analyzing the tolerance factor and electronegativity difference of the present ABO3-type ilmenite, the experience tolerance factor value and experience electronegativity difference value to form stable ilmenite
compound were obtained, that is, t > 0.80 and e > 1.465, and the lowest limit of the octahedral factor for ilmenite formation is 0.48. 相似文献
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Peng ZHANG Yunhui DU Hanwu LIU Daben ZENG Jianzhong CUI Limin BA Department of Mechanical Engineering Beijing Jiaotong University Beijing China Department of Mechanical Engineering Tsinghua University Beijing China Metal Forming Department Northeastern University Shenyang China Anshan Automobile Fittings Factory Anshan China 《材料科学技术学报》2005,21(4):589-592
The rolling treatment of steel-mushy QTi3.5-3.5 graphite composite was conducted under different relative reduction at room temperature. The effect of room-temperature rolling on interfacial mechanical property of steel-mushy QTi3.5-3.5 graphite composite was studied and the relationship between interfacial shear strength and relative reduction was established. The results show that, for steel-mushy QTi3.5-3.5 graphite composite, which consists of 1.2 mm-thick 08AI steel plate and 2.8 mm-thick QTi3.5-3.5 graphite layer, there is a nonlinear relationship between interfacial shear strength and relative reduction in graphite layer. When relative reduction is smaller than 1.1%, interfacial shear strength increases with increasing the relative reduction. When relative reduction is larger than 1.1%, interfacial shear strength decreases with increasing the relative reduction. When relative reduction is 1.1%, the largest interfacial shear strength of 145.2 MPa can be obtained. 相似文献