基于材料挤出和光固化复合成型的智能陶瓷刀具增材制造工艺机理研究

As a key component of intelligent machining equipment, smart cutting tool can effectively advance the development of intelligent manufacturing. In this project, an additive manufacturing process based on the combination of material extrusion and photo-curing is proposed, which could resolve the conflict of requiring the fluidity as well as shape preserving of slurry in material extrusion process, and could fix the problem that multi-material structure is not easily accessible by stereolithography. With this proposed method, a new kind of ceramic smart cutting tool with embedded temperature and wear switch sensors, with inner cooling channel with heat pipe effect, and with multi-material functional gradient structure can be obtained. In this project, rheological properties and self-propagation photo-polymerization waveguide (SPPW) characteristics of the photosensitive slurry are going to be investigated through multi-factor analysis, multi-objective optimization and the distribution model of multi size ceramic particles in extruded filament based on discrete element analysis. We will research the quantization and uniformity of the space shrinkage in the drying, debonding and sintering processes by establishing the mathematical model of spatial shrinkage of different slurries in different shapes, positions and directions. Optimization algorithms for the route of inner thermal channels and distribution of functional gradient structure materials are to be studied based on the aware of the internal thermal-stress field distribution of the tool body by cutting experiment and finite element model (FEM). The evaluation of cutting performance, perceptive function and functional gradient structure of the new ceramic smart cutting tool will also be made in this project. Through this project, we can obtain a new process of multi-material additive manufacturing and contribute to the development of intelligent equipment and intelligent manufacturing.

智能切削刀具是智能加工装备的关键部件，能有效推进智能制造的发展。本项目提出一种基于材料挤出和光固化复合成型的增材制造工艺，解决材料挤出成型要求浆料同时具备流动性和保形性的矛盾和光固化成型难以制成多材料结构零件的问题，制造内部具有温度和磨损开关传感器、热管效应散热通道和多材料功能梯度结构的新型智能陶瓷刀具。本项目通过多因素分析、多目标优化和基于离散元的多粒径陶瓷颗粒在丝线形挤出浆料中的分布模型，研究光敏挤出浆料的流变特性和自传导光固化特性；建立干燥、脱胶和烧结过程中的材料空间收缩数学模型，研究多材料结构空间收缩的量化和保证空间收缩一致性的方法；通过切削实验结合有限元计算获得刀具内部热力场分布，研究散热通道空间路径和功能梯度结构材料分布的优化方法；并综合评价新型智能陶瓷刀具的切削性能、感知功能和功能梯度结构。通过本项目的研究，可形成多材料复杂结构增材制造新工艺，促进智能装备和智能制造的发展。

智能切削刀具是智能切削加工装备的关键部件，能有效推进智能制造的发展。本项目提出了一种基于材料挤出和光固化复合成型的增材制造工艺（MEX-PPM），解决了材料挤出成型要求浆料同时具备流动性和保形性的矛盾和光固化成型难以制成多材料结构零件的问题，研发了MEX-PPM完整工艺和关键设备，制出了变形率低、内嵌温度传感器、多材料结构、结构致密的智能陶瓷刀片。浆料与坯件方面，研究发现，以经0.15wt%油酸为表面改性剂处理后的氧化铝粉末和HDDA为分散剂制成的陶瓷浆料具备更好的流动性和稳定性；81wt%氧化铝陶瓷浆料在流动性和固相含量之间得到最佳平衡；提高温度也有利于浆料的流动和挤出；坯件的保形性方面，固相含量越高变形率越小；以此确定了81wt%氧化铝陶瓷浆料的制备工艺。装备研制方面，经验证与优化设计，提出并确定了气压驱动、二通阀控制的浆料挤出方案和环形UV固化光投射方案，试制了MEX-PPM复合成型设备。脱脂和烧结工艺方面，提出了3阶保温法，减少脱脂和烧结过程中的变形。为进一步提升制件性能，研究发现以10wt%氧化铝纳米颗粒和30wt%TiCN微米颗粒作为添加相，制件能获得更好的致密性和力学性能。智能切削刀片应用方面，制出了内嵌温度传感器的陶瓷刀片。项目提出并实现的基于材料挤出和光固化复合成型的增材制造工艺与设备为高效制造高性能陶瓷刀片提供了新路径，智能陶瓷刀片的方案对推进切削加工过程的智能化有积极作用。