陶瓷刀具高温力学行为演变机理及其与刀具服役性能间的映射关系研究

The effects of cutting tool’s high temperature mechanical behavior evolution on the tool’s service performance were seldom considered in the studies of cutting tool material fabrication, cutting performance evaluation and tool selection, but in fact, high temperature performances are better fit for the actual condition in service. It is proposed to study the evolution mechanisms of the ceramic tool’s high temperature mechanical behavior and the mapping relationship between the high temperature mechanical behavior and the service performance. The quasi static and dynamic mechanical properties at high temperature of the ceramic tool materials will be investigated; the evolution law and evolution mechanisms of the ceramic tool’s high temperature mechanical behavior will be revealed. The influencing mechanism of the evolution law of tool’s high temperature mechanical behavior on tool life, tool failure mechanism and the machined surface quality of difficult-to-cut material will be deeply revealed. The model of mapping relationships between the high temperature mechanical behavior and the service performance will be established. The results about the influencing mechanism of the ceramic tool’s high temperature mechanical behavior on tool life, tool failure mechanism will provide important theoretical basis which is more in line with the service conditions for better development of advanced ceramic tool materials; the study about mapping relationships between the tool’s high temperature mechanical behavior and the service performance has an important theoretical and practical significance for the evaluation and prediction of the tool’s service performance, better selection for high speed cutting tools, optimization of cutting parameters and achieving high quality machining of difficult-to-cut materials.

针对目前在刀具材料研制、刀具性能评价以及刀具选用的研究中极少涉及基于刀具高温力学行为演变对其服役性能影响作用的问题，本项目提出研究更符合服役条件下的刀具高温力学行为演变机理及其与刀具服役性能的映射关系。主要研究陶瓷刀具材料的高温准静态、高温动态力学行为及其随机分布规律，深入揭示刀具高温力学行为的演变机理；研究刀具在高速切削时的力学行为演变机理对刀具寿命、刀具失效机理和加工表面质量的影响机制；建立刀具材料高温力学行为与刀具寿命和加工表面质量等刀具服役性能的映射关系模型。有关刀具高温力学行为演变及其对刀具寿命、刀具失效机理影响机制的研究将为新型高速切削刀具材料的研制提供更符合服役工况的重要理论依据；刀具高温力学行为与服役性能映射关系的研究将对刀具服役性能评价与预测、刀具材料的优选、切削参数优化、实现难加工材料的高质量切削具有重要的理论和实际意义。

陶瓷刀具在干切削难加工材料时处于高温环境下，其力学行为与室温下截然不同，不同刀具其演变规律也不相同，因此无论在刀具材料研制时还是选用刀具材料或切削性能预测评价时仅以室温力学性能为依据往往达不到高性能切削的预期效果。.本项目针对高速干切削加工时陶瓷刀具在高温服役条件下的力学行为演变展开研究，揭示了陶瓷刀具材料的高温力学性能演变规律及演变机制；结合高温力学行为的演变深入分析了其对刀具寿命、刀具失效机理以及加工表面质量的影响机制；建立了刀具高温力学行为与服役性能的映射关系，并对具有不同高温力学性能的陶瓷刀具切削性能进行了模糊评价。研究表明，室温力学性能不能作为预测和评判陶瓷刀具切削性能的标准，陶瓷刀具的高温力学性能与切削性能之间具有高度相关性，研究获得了各力学性能指标对刀具不同失效形式的影响权重。本项目的研究成果对刀具服役性能评价与预测、刀具材料的选用、切削参数优化、新型高性能陶瓷刀具的设计研制以实现难加工材料的高质量切削提供给了重要的理论依据并具有重要的实用价值。.此外针对高速切削镍基高温合金时刀具磨损特点，从提高刀具抗磨损性能的角度出发，研究了刀具失效寿命与刀具材料性能之间的关系，建立了陶瓷刀具材料力学性能预测模型，研制了具有良好切削性能的新型ASWT陶瓷刀具，该刀具能够在400 m/min的高速下高效干切削镍基高温合金，有待推广应用。