基于高温力学行为的陶瓷刀具精细制备及其极端切削使役性能研究

Based on the accumulation of research experience in the research group, it is fully recognized that the problems which the current design and manufacturing processes of ceramic cutting tool are usually estimated on mechanical properties of cutting tool materials at room temperature, as well as shortcomings of ceramic cutting tool in use , such as instability. For efficient processing of high-temperature alloys in the conditions of harsh cutting environment, such as high temperature, high pressure and strain hardening, the research will be started from the high temperature mechanical properties and behavior of ceramic cutting tool. The experiments, simulation, theory analysis and other methods will be used to explore the microstructure evolution, the decay mechanism of mechanical properties at high temperature and the failure mechanism of ceramic cutting tool in extreme high-speed cutting environment. This research will be focused on the coupling relationship between the high temperature mechanical behavior of ceramic cutting tool material and the cutting performance, which can contribute to design the components of the ceramic cutting tool in a reverse direction and put forward the control strategy of the structure manufacturing to realize the high reliability target when the ceramic cutting tool machines the high-temperature alloys with high efficiency in the extreme environment . This study will be overcomed the traditional development method that could not couple between the room temperature mechanical properties and the cutting performance. With a view to develop composite ceramic cutting tool components grades which are suitable for continuous and intermittent machining three categories of high-temperature alloys with high efficiency, this study is expected to make a breakthrough in the design and cutting reliability of high-speed cutting tools for high-temperature alloys.

本研究在课题组多年研究经验积累基础上，充分认识到目前陶瓷刀具设计、制造过程存在通常以刀具材料的常温力学性能作为判断基准的问题，以及陶瓷刀具使用性能不稳定等缺点，面向高效加工高温合金时的高温高压、加工硬化等极端恶劣切削使役环境，从陶瓷刀具的高温力学性能和行为出发，通过实验、仿真与理论研究等方法，探索高温时陶瓷刀具微观结构演变、力学性能衰变的行为机理和其在极端切削使役环境中失效机理，重点研究陶瓷刀具材料的高温力学行为与刀具切削使役性能之间的耦合关系，反向准确设计陶瓷刀具组分，提出结构制造的控制策略，实现陶瓷刀具在高效切削高温合金的极端使役环境下高可靠性目标。本研究将克服刀具传统研制方法中无法将刀具常温力学性能与刀具切削性能耦合的局限性，有望在高温合金高速切削用刀具的设计制备和切削可靠性上取得突破，以期开发出适合连续和断续高效切削加工三大类高温合金的复合陶瓷刀具牌号。

镍基高温合金在1000 ℃高温下仍维持优异的力学性能及良好的抗氧化性、抗腐蚀性，已成为军民用能源转换装置热端部件不可替代的关键材料。然而其切削加工性差一直制约着高性能零部件的高效生产，究其原因是刀具难以适应高速切削镍基高温合金过程中的强力-热-化学多场耦合环境，表现为加工效率低、刀具寿命短和加工质量差。本项目面向高效加工高温合金时的高温高压、加工硬化等极端恶劣切削使役环境，从陶瓷刀具的高温力学性能和行为出发，通过实验、仿真与理论研究等方法，研究高温时陶瓷刀具微观结构演变、力学性能衰变的行为机理和其在极端切削使役环境中失效机理，反向设计陶瓷刀具组分，克服了刀具传统研制方法中无法将刀具常温力学性能与刀具切削性能耦合的局限性。取得如下研究成果：（1）研究了三种不同牌号的商用陶瓷刀具高温力学性能与其切削性能及失效机理之间的关系，在此基础上提出了满足镍基高温合金GH4169高速切削要求的陶瓷刀具设计原则。 （2）设计并优化了AWN15新型陶瓷刀具材料体系，确定了粉末分散与陶瓷刀具烧结工艺，揭示了刀具材料的协同增韧机制和高温力学行为演变机制。 （3）仿真研究了AWN15新型陶瓷刀具高速切削镍基高温合金GH4169时的切削力和温度场分布，优化了 AWN15陶瓷刀具结构及几何参数。（4）精细制备出高温力学性能优良的AWN15新型陶瓷刀具。（5）研究了AWN15新型陶瓷刀具高速切削镍基高温合金GH416的使役性能，研究结果表明，AWN15新型陶瓷刀具高速切削镍基高温合金 GH4169的最佳切削用量为切削速度120 m/min，背吃刀量0.8 mm，进给量0.10 mm/r，达到半精加工要求，刀具耐用度比三种商用陶瓷刀具中切削性能最优的CC陶瓷刀具提高了18%，表现出较好的抗沟槽磨损与抗破损失效能力,研究成果对推动我国刀具材料的发展和高速切削技术进步具有重要意义。