【作者】 杜云慧；

【导师】 何庆复；

【作者基本信息】 北京交通大学 ， 车辆工程， 2013， 博士

【摘要】 摘要：为了研发国民经济各领域急需的高性能钢背铜石墨轴瓦板,本文开展了钢背铜石墨轴瓦板的半固态铸轧成形与后处理技术及理论方面的研究工作。研发了双叶片层搅拌桨电磁机械复合搅拌技术,形成了浆料制备基础理论,成功制备了组织均匀的含有10vo1%石墨颗粒和1vo1%碳化硅颗粒的铜石墨半固态浆料,为解决铜石墨半固态浆料制备中亟待解决的“阻止外加石墨与碳化硅轻颗粒上浮、实现半固态浆料组织均匀化”核心问题探索了一条新途径。确定了铜石墨复合材料半固态加工的合理技术条件,解决了铜石墨复合材料在常规铸造中存在的外加颗粒宏观偏析问题。对钢背铜石墨轴瓦板的半固态铸轧复合进行了研究,建立了力学性能、组织结构等与复合参数的关系,优化了合理技术,确定了复合机理。开展了界面残余应力的去应力退火后处理、单道次轧制后处理、二道次轧制后处理研究,得到了钢背铜石墨半固态铸轧轴瓦板的真实界面剪切强度,建立了后处理条件与力学性能的关系,确定了合理的后处理工艺,开发了可以替代去应力退火后处理技术的工艺简单、能耗小、成本低的二道次小变形轧制后处理技术。本研究得到的钢背铜石墨轴瓦板的界面剪切强度可高达140MPa左右,比采用粉末烧结轧制复合技术制备的轴瓦板的界面剪切强度90MPa左右至少提高了50%以上,可见,本研究为制备可满足“高速、重载”要求的高性能钢背铜石墨轴瓦板探索了一条新途径,为扩大钢背铜石墨轴瓦板在国民经济各领域中的应用奠定了坚实的基础。更多还原

【Abstract】 ABSTRACT:In order to develop a high-property steel-backed copper-graphite bearing plate needed urgently in national economy, the semi-solid casting-rolling forming and theoretical research work about steel-backed copper-graphite bearing plate was carried out in this paper.The electromagnetic-mechanical stirring technique with a two-layered stirrer was developed and the basic theory of slurry preparation was formed. A copper-graphite slurry with uniform distribution of graphite (10vol%) and SiC (lvol%) particles was prepared by this technique successfully. A new way to solve the key problem, namely, preventing particles from floating and realizing structural homogenization of slurry, was explored in preparation of copper-graphite slurry.The reasonable semi-solid processing condition of copper-graphite composite was determined and the problem of particle segregation in conventional casting of copper-graphite composite was solved.The relationship between mechanical property, structure and bonding parameters was established, the reasonable technique was optimized and the bonding mechanisium was determined in semi-solid casting-rolling of steel-backed copper-graphite bearing plate.Post treatment of interfacial residual stress was carried out, the true interfacial shear strength, the relationship model and the reasonable technics were got. A simple, low cost and little energy waste two-pass rolling post treatment technique which can substitute stress-eliminating annealing post treatment was developed.In this research, a high property of140MPa which is50%higher than90MPa in particle sintering rolling was achieved. It can be seen that a new way to prepare high-property steel-backed copper-graphite bearing plate for the need of "fast running and over loading" was explored and a firm foundation for widening the application of steel-backed copper-graphite bearing plate in national economy was laid.更多还原