Thermo-mechanical simulation of hard turning with macroscopic models and phase-field-models

与磨削相比，硬车削是一种有利的替代制造工艺，具有高切屑去除率，几何复杂工件的灵活性和干加工资源效率。工件材料的物理性能与未来的部件性能相关，主要受表面层形成、硬车削过程中的相变和残余应力发展的影响。考虑工件热负荷的硬态车削工艺优化需要对这些现象进行模拟映射。因此，通过使用多机制模型考虑工件材料中的相变的粘塑性变形过程的模拟代表了所提出的项目的主要目标之一。模型验证的基础上进行的高速和相变实验，以及在现场的温度和合力分量测量。此外，相场模型，以实现更好地理解在介观尺度上的相变，如奥氏体化，马氏体的形成和各向异性的发展。第一个支持期内的研究工作重点是调查适当的模拟技术，以便对硬车削过程中滚动轴承套圈中的热通量进行逼真的建模。在第二个支持阶段，第一个项目阶段所取得的成果被转移到具有轴肩的几何形状复杂的带槽车削零件上。此外，考虑到相变，相塑性和扩散过程，以及使热有利的加工策略的推导出一个广泛的材料模型的发展是打算。在第三个支持阶段，仿真模型将用于考虑上游或下游加工过程，目的是导出补偿策略，这将通过修改过程控制或过程顺序来减少热变形。

Compared to grinding is hard turning an advantageous alternative manufacturing process with respect to high chip removal rates, flexibility in case of geometrically complex work pieces and dry processing resource efficiency. The physical properties of the work piece material, which are relevant for the future component behavior, are essentially influenced by the surface layer formation, the phase transformations during the hard turning process and the development of residual stress. The process optimization of hard turning concerning the work piece thermal load requires the simulative mapping of these phenomena. Hence, the simulation of viscoplastic deformation processes taking into account the phase transformations in the work piece material by the use of a Multi-Mechanism-Model represents one of the main goals of the proposed project. The model validation is carried out on the basis of high speed and phase transformation experiments as well as in-situ temperature and resultant force component measurements. Moreover, phase-field models are used in order to achieve a better understanding of the phase transformations at the mesoscale such as austenitization, martensite formation and development of anisotropy. The research work within the first period of support focuses on the investigation of adequate simulation techniques that enable a realistic modeling of the thermal flux in rolling bearing rings during hard turning. In the second period of support, the results achieved in the first project phase are transferred to geometrically complex grooved turned parts with shaft shoulders. Furthermore, the development of an extensive material model taking into consideration the phase transformations, the phase plasticity and diffusion processes as well as enabling the derivation of thermally profitable machining strategies is intended. In the third period of support, the simulation models will be used to consider up- or downstream machining processes with the aim of deriving compensation strategies, which will lead to the reduction of thermal deformations by modifying the process control or the process sequence.