Milling of WC-Co-hardmetals

由于它们的高弹性模量，与钢相比显著更高的硬度以及与陶瓷相比更高的韧性，烧结碳化物在金属成形中起着重要作用。如今，在许多情况下，这些部件是使用时间和成本密集型的研磨工艺生产的，并且由于原始边缘区域损坏，它们通常被精加工。由于高硬度切削材料的不断发展，铣削可以被认为是一种替代方法。迄今为止，对烧结碳化物铣削的研究仅在微切削领域进行，因此有关性能和工艺限制的重要科学问题目前尚未解决。到目前为止，已经进行了基础研究，特别是对于运动学上更简单的刨削/开槽工艺，尽管初步研究表明烧结碳化物的铣削具有很高的潜力。然而，需要进一步的基础研究材料，工艺参数和加工策略对切削力，刀具磨损和工件质量的影响。研究状态的可用结果和申请人所做的初步工作表明，烧结碳化物铣削的潜力，尽管该工艺由于缺乏技术基础而几乎没有被考虑。该研究项目的主要目标是对烧结碳化物铣削过程的理解做出根本性贡献。这仅限于WC-Co碳化物的加工。研究的重点是刀具的影响，特别是稳定的切削刃，工艺变量，加工策略和硬质合金的负载依赖性的边缘区损伤的工件。为了更准确地理解切削机理和局部边缘区损伤，在一定的参数组合下进行了直线切削实验，并根据实验结果建立了描述硬质合金材料硬度对零件边缘区影响的经验模型。其目的是预测发生的边缘区损伤作为未来加工任务的材料硬度的函数。此外，该模型使工艺设计，以铣削硬质合金部件在所需的quality.In的结论，性能的基本评价，以及在烧结碳化物铣削过程中的限制的确定进行。被认为是一个重要的研究项目的结果，所生产的组件的参数依赖的损伤深度。它可以用于推导未来的处理策略，以尽量减少发生的边缘区损伤。

Due to their high modulus of elasticity, the significant higher hardness compared to steels as well as the higher toughness compared to ceramics sintered carbides play an important role in metal forming. Nowadays the components are in many cases produced using time- and cost-intensive abrasive processes and due to the originated edge zone damage they are often finished. As result of the progressing development of highly hard cutting materials milling can be considered an alternative. Research on milling of sintered carbides has until now only been conducted in the field of micro cutting, so that important scientific questions concerning performance and process limitations are currently unsolved. Until now the fundamental studies have been conducted especially for the kinematic simpler process of planing/ slotting, though the preliminary studies indicate that milling of sintered carbides offers a high potential. However further fundamental research on the influence of material, process parameters and processing strategies on cutting force, tool wear and work piece quality is required.The available results of the state of research and the preliminary work done by the applicant show the potential of milling of sintered carbides, though the process has been hardly considered for lack of technological fundaments. The main objective of this research project is a fundamental contribution to the understanding of the processes occurring during milling sintered carbides. This is restricted to the machining of WC-Co carbides. The study focuses on the investigations on the influence of the tool, especially the stabilization of the cutting edge, the process variables, the processing strategies and the carbide alloys on the load-dependant edge zone damage in the work piece. For receiving a more precise understanding of the cutting mechanism and the local edge zone damage slotting experiments, i.e. with linear cutting motion, are additionally conducted at certain parameter combinations.Based on the experimental findings an empirical model to describing the impact on the edge zone of the component as a function of the carbide alloy, i.e. the material hardness, is developed. The objective is to predict the occurring edge zone damage as a function of the material hardness for future machining tasks. Furthermore the model enables the process design in order to milling a carbide component in the required quality.In conclusion, a fundamental evaluation of performance as well as a determination of process limitations in milling of sintered carbides is carried out. The parameter-dependant depth of damage of the produced component is considered as a significant result of the research project. It can be used for deriving future processing strategies in order to minimize the occurring edge zone damage.