Determination of the microscopic wear mechanisms and operational suitability of diamond and cBN for the precision machining of hardened steel under variation of the thermomechanical load using multiscale measurement methods

使用多尺度测量方法确定热机械载荷变化下金刚石和 cBN 精密加工的微观磨损机制和操作适用性

• 批准号: 501935718
• 负责人: Professor Dr.-Ing. Dirk Biermann
• 金额: --
• 依托单位: Lehrstuhl für Experimentelle Physik II
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/501935718?language=en
• 关键词: Determination; microscopic; wear; mechanisms; operational

Cubic boron nitride (cBN) is the superabrasive material frequently used for machining steels due to its high thermochemical resistance. In comparison to cBN, diamond possesses superior mechanical properties and allows for longer tool lifetimes at low process temperatures; however, it is less temperature-resistant. The wear mechanisms of the diamond and cBN tools for machining steels are not understood yet, thus limiting their applications and, in turn, indicating a research gap. Moreover, it is of particular interest how the predictability of the precision-grinding result and the reliability of the abrasive grain functionality using diamond and cBN could be enhanced. The understanding of the interaction of diamond and cBN with a steel surface and, hence, of the abrasive grain wear at the nanoscale is moreover an open tribological aspect. It could be clarified by a microscopic description of the wear-relevant properties of the grain surface and their dependences on the temperature and pressure.The project aims at describing chemical, structural, and physical surface properties of diamond and cBN abrasive grains as well as of the workpiece made from hardened bearing steel 100Cr6 at the meso- and nanoscale; following the conditions of grinding processes, the thermomechanical load is varied. The mutually correlated properties shall characterize the grain wear mechanisms for the precision grinding as well as the suitability and efficiency of the abrasive grains for realizing a high surface quality of the workpiece. On the one hand, acoustic phonons shall describe the energy which is dissipated into the carbon or boron-nitride atomic lattice during the grinding process and shall be linked with macro- and microscopic analyses of the wear and friction. On the other hand, application-specific process-parameter spaces for the precise machining with cBN and diamond grinding tools and potential limits and advantages of using diamond in comparison to cBN will be deduced. The wear resistance and the material abrasion performance will finally be elucidated for the target-oriented and economical application of cBN and diamond as grinding medium in precision grinding.In that context, complementary and multiscale methods, which embrace macro- and microscopic studies of structural-topographic features will be used and interatomic interactions which are relevant to chemical and physical properties will be analyzed by means of Raman and Brillouin laser-light scattering. The thermomechanical load of diamond and cBN abrasive grains being in contact with the workpiece surface will be recorded in situ and operando by a quantum sensor measurement of pressure and temperature.

立方氮化硼(CBN)具有较高的耐热化学性，是加工钢的常用超硬材料。与立方氮化硼相比，金刚石具有更好的机械性能，并允许在较低的工艺温度下使用更长的工具寿命；但它的耐温性较差。用于加工钢的金刚石和立方氮化硼刀具的磨损机理尚不清楚，因此限制了它们的应用，进而表明了研究空白。此外，人们特别感兴趣的是如何提高精密磨削结果的可预测性和使用金刚石和CBN磨粒功能的可靠性。此外，了解金刚石和立方氮化硼与钢表面的相互作用以及纳米级的磨粒磨损也是一个开放的摩擦学方面。通过微观描述磨粒表面的磨损相关特性及其与温度和压力的关系，可以阐明这一点。该项目旨在描述金刚石和CBN磨粒以及淬火轴承钢100Cr6制成的工件在介观和纳米尺度上的化学、结构和物理表面特性；随着磨削工艺条件的变化，热机械载荷是不同的。这些相互关联的特性将表征精密磨削的磨粒磨损机制，以及磨粒实现高表面质量的适宜性和效率。一方面，声学声子应描述磨削过程中耗散到碳或氮化硼原子晶格中的能量，并应与磨损和摩擦的宏观和微观分析相联系。另一方面，将推导出使用CBN和金刚石磨具进行精密加工的特定应用工艺参数空间，以及使用金刚石与CBN相比的潜在限制和优势。最后将阐明CBN和金刚石作为磨削介质在精密磨削中的定向和经济应用的耐磨性和材料磨损性能。在此背景下，将使用互补和多尺度的方法，包括宏观和微观结构-形貌特征的研究，并将利用拉曼和布里渊激光散射分析与化学和物理性质相关的原子间相互作用。金刚石和立方氮化硼磨粒与工件表面接触的热机械载荷将被现场记录下来，并通过压力和温度的量子传感器测量进行操作。