【作者】 涂明金；

【导师】 赵玉谦；

【作者基本信息】 吉林大学 ， 钢铁冶金， 2007， 硕士

【摘要】 将铸造过程与Fe-Ti- C-Al体系SHS反应有机结合,成功制备出TiCp局部增强铸造钢基复合材料。利用添加Cu, Ni, Mo, Zr等添加剂,及热处理来改善TiCp局部增强铸造钢基复合材料的形貌,硬度及耐磨性。采用Fe-Ti-C-Al体系,将粉料充分混合压制成约理论密度60%的预制块,经预处理后放置在铸型内,利用高温钢液的热能引发SHS反应,使液态金属成型和在钢液内内生TiC增强颗粒同时完成。添加了Cu, Ni, Mo, Zr等添加剂减小TiC颗粒尺寸,提高TiCp局部增强铸造钢基复合材料的硬度及耐磨性。利用淬火处理改善TiCp形态,提高TiCp增强区和基体区的宏观硬度。并对TiCp局部增强铸造钢基复合材料的耐磨性进行了研究。为TiCp局部增强铸造钢基复合材料的应用,提供了可供参考的理论与技术依据更多还原

【Abstract】 With the development of modern industry urgent demand the structure can work in the high temperature, high speed and violent abrasion situations, the pure steel materials are more and more hard to satisfy the request, and because of steel matrix composites have the merits such as, high compare intensity, compare modulus, good heat transmit, good electrical conductivity, wear-resistance, high temperature performance, lower heat inflate quotiety, and high size stability, etc. so the steel matrix composites became a new field of metal matrix composites, having an extensively applied foreground in industry. In all steel matrix composites, Fe-TiC composites is subjected to most people’s favor, this is because in the all carburet ceramics, the resources of TiC is abundant and the hardness of TiC particulate is highest and hot stabilities, the most valuable is that the TiC particulate can be wetted by Fe liquid in high temperature, the wet angleθ<90°. Therefore, to meet the demand of the development of modern industry and inject new energy to steel materials, developing an Fe- TiC composites which has the merit of good function, low cost and is suitable for large scale manufacture, is the mission of material researcher.As the way of joining the particulates, the manufacture technique of PRMMCs (Particulate Reinforced Metal Matrix Composites) can be divided into ex situ and in situ. There are some defects in the technology of ex situ particulates:①the size of the particulate is influenced by the starting materials, and they have large size and always is 1~2μm or tens of microns;②particulates are prone to be contaminated because of the absorbed gas and impurities at the surface, so there is poor wettability between particulate and matrix. Thus, it is difficult to control the interface reactions between them;③these particulate will be oxidated, burned up, decomposed and so on when they are added into high temperature melts; and④ some other problems may happen when they are added, for example, gas and lard may be entangled into the melts. Compared with the conventional MMCs fabricated by ex situ methods, the in situ MMCs exhibit the following advantages:①the in situ formed reinforcement is thermodynamically stable at the matrix, leading to the less degradation in elevated-temperature service;②the reinforcement-matrix interface is clean, resulting in a strong interfacial bonding;③the in situ formed reinforcing particulate is finer in size and their distribution in the matrix is more uniform, yielding better mechanical properties. Consequently, in situ processing techniques are able to solve the problems of the ex situ.But its development is dropped behind light-metal composites, because the steel has high melting point and ceramic reinforced particulates tending to gather. So, this paper mainly studied the influence of TiC Particulate Reinforced Steel Composites by additives and heat treatment, to improve the size and distributing of TiCp in composites reinforced area. The main works of this study are as follows:(1) Put additives Cu、Ni、Mo、Zr into Al- Fe- Ti- C system to make compacts respectively, use the steel liquid’s high temperature to ignite the compacts, can manufacture in situ TiCp reinforced steel matrix composites successfully. Additive Cu, Ni, Mo, Zr can make the size of TiCp smaller, and Cu, Ni, Mo can improve the wettability between the TiCp and steel liquid, and restrain the forming of Fe2Ti and Al4C3.(2) Additive Cu, Ni can improve the macrohardness of composites evidently, but additive Mo, Zr cannot improve the macro hardness of composites obviously, because of Cu, Ni can improve the density of composites, and additive Mo, Zr”s joining, make the composites have defects that make the macrohardness isnot very ideal.(3) As cast composites, Under the condition of this experiment, and under apllied loads of 5N, 10N, 20N performed on abrasive paper of 600 grit, when the composites contain 0.4 wt.% Cu, the wear resistance is the best, the relative resistances compared to 45# steel Matrix, are 5.55、4.60 and 4.21. Under apllied loads of 5N, 10N, 20N performed on abrasive paper of 320 grit, when the composites contain 0.4 wt.% Cu, the wear resistance is the best, the relative resistances compared to 45# steel Matrix, are 3.63、3.49 and 3.40.(4) The matrix of the composites after quenching and temper is martensite, the distribution of TiCp in reinforces area is uniformity. Most of the TiCp distribute at the boundary of austenitic.(5) Under the condition of this experiment, after quenching and temper, and under apllied loads of 5N, 10N, 20N performed on abrasive paper of 600 grit, when the composites contain 0.4 wt.% Cu, the wear resistance is the best, the relative resistances compared to 45# steel matrix, are 6.59,5.41 and 4.34. Under apllied loads of 5N, 10N, 20N performed on abrasive paper of 320 grit, when the composites contain 0.4 wt.% Cu, the wear resistance is the best, the relative resistances compared to 45# steel Matrix, are 4.07,3.54 and 3.42.(6) The composites after heat treatment compare to as cast composites, the ploughings are thin, shallow and discontinuousness,TiC particulates seldom brush off. Mainly becaue the harness of matrix and the capability of matrix’s support to TiC improved evidently, thus further raised the wearable of composites.更多还原