【作者】 岳彩旭；

【导师】 刘献礼；

【作者基本信息】 哈尔滨理工大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 与磨削相比,硬态切削具有很好的工艺柔性、经济性和环保性能看,该工艺能精确地将硬度大于HRC50得毛坯直接加工成工件。因此,用硬态切削来代替磨削在当今的机械加工中得到了越来越广泛的?应用,并且在一定的条件下,硬态切削已经成为代替磨削的首选工艺。因此,深入研究硬态切削机理并对其进行工艺优化有重要的意义。在阐述国内外研究现状的基础上,本文通过理论分析与实验研究相结合,从金属切削原理入手,借助有限元仿真手段对PCBN刀具硬态切削淬硬钢GCr₁₅的过程进行了较为深入的研究。通过设置合理边界条件,结合网格自适应控制技术建立了二维完全热力耦合的有限元模型,研究了带状切屑的产生过程。借助有限元仿真结果文章本文研究了刀具几何参数和切削条件对对切削过程的影响。通过采用合理的材料本构模型和剪切失效模型本文建立了锯齿状切屑产生过程的有限元模型,并利用有限元结果分析了锋利刃口、倒圆刃口和倒棱刃口对切削过程的影响。结合了网格自适应技术和删除技术,采用质量放大技术,建立了硬态切削过程的三维有限元仿真模型。为了验证仿真结果的正确性与否,本文采用山特维克公司的PCBN刀具在CA6140车床上对淬硬轴承钢GCr₁₅进行了一系列切削力、切削温度实验。通过试验与仿真分析对比,有限元仿真切削力、切削温度和已加工表面残余应力有较好的精度。采用的模拟方法可以部分的取代实验研究,拓展了有限元理论的应用范围,促进了硬态切削机理的研究,为刀具几何参数和切削工艺的优化提供了有益的参考。更多还原

【Abstract】 Compared with grinding, hard-state cutting process has a very good process flexibility, economy and environmental protection, in this process, the hardness of the rough higher than HRC50 can be processed directly into work piece accurately. Thus, instead of grinding, hard-state cutting in today’s machining has been increasingly widely used, and under certain conditions, hard-state cutting has become the first choice to replace grinding process. Therefore, in-depth studying of the mechanism and process optimization of the hard-state cutting has important significance.Based on describing research status at home and abroad, through combining theoretical analysis and experimental study, this paper start with the principle of metal cutting, using finite element simulation to do a more in-depth study of the process of PCBN tool hard-state cutting hardened steel GCr₁₅.By setting up reasonable boundary conditions, combining the grid adaptive control technology, two-dimensional finite element model of fully thermal coupled was established completely, cutting process of continuous chip was also studied. Using results in finite element simulation articles, the effects of cutter geometric parameters and cutting conditions take on cutting process was also researched in this paper. Under the use of reasonable material constitutive model and shear failure model, the finite element model of serrated chip formation process was set up in this paper, then using the finite element analysis consequence, influence of the cutting process caused by sharp edge and radius edge chamfering edge circle was analyzed.By combining with the technology of grid adaptive and delete, using the technology of quality amplification, three-dimensional finite element simulation model of hard cutting process was build. In order to verify the correctness of simulation results or not, this paper uses PCBN cutting tools of Sandvik for hardened bearing steel GCr₁₅ to conduct a series of cutting force and cutting temperature experiments in CA6140 lathe. Analyzed and compared by experiment and simulation, finite element emulates cutting forces, cutting temperature and surface residual stress, which have better accuracy. Using the simulation method can replace part of the experimental research, expand the application of finite element theory, promote the research of hard-state cutting mechanism and provide a useful reference for cutting tool geometry optimization and process.更多还原