Modelling and simulation of internal traverse grinding - from micro-thermo-mechanical mechanisms to process models

电镀CBN砂轮内横磨（ITG）是一种现代化、高效率的磨削工艺，具有巨大的工业应用潜力。这是由一个功能分级几何砂轮，分为粗加工和精加工部分。由于这种特殊的几何形状，该工艺能够产生内部工件表面的优越表面质量，以及只需一次通过工具的高材料去除率。这适用于例如轴承套圈或齿轮的制造。该工艺的特点是其工具和工件之间的小接触区，从而导致后者高度集中的热机械负荷。反过来，这可能会导致工件表面的不必要的相变以及成品零件的形状和尺寸误差。本项目旨在开发一个整体仿真框架，该框架能够预测制造过程中的上述误差，并支持开发适当的补偿策略。该仿真框架主要由三个部分组成。首先，在中尺度上建立一个有限元模型，以捕获单个cBN颗粒的接近度。这与第二部分相结合，即第三部分的宏观模拟，即统计近似模型。这种混合模拟方法能够对所考虑的磨削过程进行详细的热-机械研究。为了在两个尺度上预测相变和热致误差，正在开发适当的材料模型。除了建模，实验将使用一个典型的工件几何包括三种不同的材料厚度进行。工件材料选用淬火冷作钢102Cr6和淬火钢16MnCr5。

Internal Traverse Grinding (ITG) with electroplated CBN wheels is a modern, highly efficient grinding process holding a great potential for industrial applications. This is enabled by a functionally graded geometry of the grinding wheel which is divided into a roughing as well as a finishing section. Due to this special geometry, the process is capable of generating superior surface qualities of internal work piece surfaces along with a high rate of material removal with just one single pass of the tool. This is applicable to e.g. the manufacturing of bearing rings or gears. The process is characteristic through its small contact zone between tool and work piece, thus resulting in a highly concentrated thermo-mechanical load on the latter. In turn, this can induce unwanted phase transformations of the work piece surface as well as errors in shape and dimension of the finished part.The present project aims at the development of a holistic simulation framework that is able to predict the above-mentioned errors within the manufacturing process and that supports the development of appropriate compensation strategies. This simulation framework mainly consists of three components. First, a finite-element-model on a meso-scale to capture the proximity of one single cBN grain. This is coupled to the second component, a macro-scale simulation by the third one, a statistical approximation model. This hybrid simulation approach enables the detailed thermo-mechanical investigation of the grinding process under consideration. For the desired prediction of phase transformations and thermally induced errors on both scales, appropriate material models are being developed.Apart from modelling, experiments will be carried out using an exemplary work piece geometry including three different material thicknesses. As work piece materials, hardened cold work steel 102Cr6 and case-hardened steel 16MnCr5 will be used.