La2O3/SiCw/TiCN纳米无粘结相表面微织构刀具及其高速干切削性能研究

In the face of the issues of intensified friction, elevated temperature and declined tool life expectancy which are brought about by high speed dry cutting, this project is intended to tentatively design and prepare nanometer binderless titanium carbonitride based cutting tool strengthened and toughened by La2O3 and SiCw and to study the performance of high speed dry cutting. The project systematically explores the impact of La2O3 and SiCw on nanometer binderless titanium carbonitride cutting tool materials in terms of microstructure and mechanical properties, elaborate on its strengthening and toughening mechanism, examine the capability of spark plasma sintering to control the morphology of surface micro texture, analyze the reflective relationship between the form of surface micro texture and tribology performance of La2O3/SiCw/TiCN nanometer binderless cutting tool materials, optimize the form of surface micro texture, and disclose the mechanism of durability and friction reduction.The project also examines the performance of high speed dry cutting featuring La2O3/SiCw/TiCN nanometer binderless tool with surface micro texture, establishes the relational model among surface micro texture and mechanical properties of La2O3/SiCw/TiCN nanometer binderless tool and the performance of the high speed dry cutting, explores the theories and methods pertaining to the optimization of high speed dry cutting performance of La2O3/SiCw/TiCN nanometer binderless tool with surface micro texture, providing the theoretical foundation for the development and application of TiCN based nanometer biderless tool with surface micro texture.

针对高速干切削带来的摩擦加剧、温度上升和刀具寿命下降的问题，项目拟设计制备La2O3和SiC晶须（SiCw）强韧化的纳米无粘结相碳氮化钛(TiCN)基刀具，考察其高速干切削性能。系统地研究La2O3和SiCw对TiCN基纳米无粘结相刀具材料微观组织、力学性能的影响规律，阐明其强韧化机制；研究放电等离子烧结技术对表面微织构形貌的控制能力，分析表面微织构形式与La2O3/SiCw/TiCN纳米无粘结相材料摩擦性能的映射关系，优化表面微织构形式，揭示其耐磨减摩机理；研究具有表面微织构的La2O3/SiCw/TiCN纳米无粘结相刀具的高速干切削性能，建立La2O3/SiCw/TiCN纳米无粘结相刀具表面微织构、材料力学性能与刀具高速干切削性能间的关系模型，探索优化La2O3/SiCw/TiCN纳米无粘结相刀具高速干切削性能的理论与方法，为TiCN基纳米无粘结相表面微织构刀具的开发和应用提供理论支撑

切削过程中刀具承受巨大的热力耦合作用，尤其在高速干切削情况下。项目从提高刀具力学性能、降低刀具表面摩擦和温度的角度，研究提高刀具寿命的方法，主要的研究工作如下。.采用放电等离子体烧结技术，在较宽的温度范围研究了纳米TiCN、微米TiCN、TiCN/Co、TiCN/SiCw/Co、La2O3/SiCw/TiCN/Co等材料的制备工艺，采用排水法、三点弯曲法和维氏硬度计测试了材料的密度、强度和硬度，并采用扫描电镜观察了材料的微观组织，结果表明：纳米TiCN在放电等离子烧结下，颗粒长大迅速，且致密化程度低；少量SiCw和La2O3的加入可以大大提高TiCN/Co的密度、强度和硬度。对比研究了La2O3/SiCw/TiCN/Co系列刀具的刀具寿命，并对刀具的磨损机理进行了分析。实验研究了沟槽形态和深度对切削过程切削力、切屑成形的影响，并对微织构刀具的减摩机理进行了探讨。从提高刀具表面减摩耐磨性能的角度，研究了功能梯度金属陶瓷和硬质合金刀具的制备及其切削性能；研究了氮化烧结工艺对刀具材料力学性能和刀具耐磨性能影响；分析了梯度刀具的减摩耐磨机理。为考察切削过程中工件和刀具材料的本构关系，发明了一种快速加热准静态高温霍普金森压杆实验装置。.本项目的研究为高效刀具的设计制备提供了理论和实验指导。