金属陶瓷微铣刀的缩尺设计与精密制造关键技术研究

The micro-miller is a special one related to the microstructure on tool material, excitation and coupling of size-effect, and structure of micro-parts, rather than considered to be narrowed on the scale of shape and structure of traditional miller. Now no researches about micro-cermet miller with mechanical properties between WC and PCD are found. Founded by the preparation theory and technology of cermet miller with a small diameter of ϕ0.5~ϕ1.0mm in our previous works, our research will investigate four parts, including scaling size-effect of micro-miller, preparation of micro-miller material, forming dynamics of geometrical structure and control of surface properties, and failure mechanism of micro-miller, based on intrinsic scale effect that microstructure directly definite the geometrical properties of mesoscopy. The aim of our research is to explain the basis of micro scale dynamics of micro-cermet miller, and find a new principle and method of manufacturing micro-miller materials, and propose a trans-dimensional combination of design theory and manufacturing method of materials and body of micro-miller, and develop a kind of micro-cermet miller with a diameter of ϕ10~500um. This research not only fills a gap of material, designs theory and manufacturing technology of micro-miller, but also more meets the demands of micro-milling many workpieces to contribute to highly manufacturing of micro-parts in our national industry. Therefore, it has a wide application prospect and great theoretical and practical significance.

微铣刀不是传统铣刀形状和结构的等比例缩小，而是与刀具材质微观结构关联、尺度效应激发与耦合、且与微小构件结构相适应性的一种特种刀具。目前国内外尚无性能介于WC与PCD之间的金属陶瓷微铣刀的相关报道。本研究在ϕ0.5~ϕ1.0mm金属陶瓷微径铣刀制备理论与技术的基础上，基于微结构直观表征介观几何性能的内禀尺度效应，在微铣刀的缩变尺寸效应、材质制备方法、结构成形动力学与表面形性控制、失效机理等四个方面开展研究，揭示金属陶瓷制作微铣刀的微尺度力学依据，发明一套制造微铣刀的材质适配性选择新原则和新方法，提出微铣刀材质和刀体跨尺度一体化设计理论和制造方法，研制出ϕ0.01~ϕ0.5mm金属陶瓷微铣刀，填补微铣刀的材质种类、设计理论和制造方法空白。本研究不仅能够填补微细切削刀具种类空白，而且能扩大微细加工构件的材料范围，为我国难加工微小构件高性能制造做出贡献，具有广泛的应用前景和重大理论与实际意义。

与传统常规金属切削相比，微细切削行为有很大的不同，微细切削刀具的几何结构和切削性能也与传统常规刀具存在差异。高速钢、硬质合金（包括涂层）、陶瓷、CBN和金刚石为目前主流的常规金属切削刀具材料，而微细切削刀具的材质多数为高速钢和硬质合金，鲜有陶瓷材质制作微铣刀的成功研究报道。陶瓷作为刀具材质候选之一，其具有高硬度、良好耐磨性和耐热性，理论上也能够满足微细切削加工的要求，尤其是难加工材料的微细切削加工需求。由此，本文针对目前硬质合金微铣刀的耐磨能力不高，涂层微铣刀面临着涂层易剥落和刃口锋利度不够的问题，将综合力学性能介于硬质合金和立方氮化硼之间的金属陶瓷材质用于制作微铣刀，开展全新的微铣刀刀具材质、设计与制造技术及其切削性能的研究。总研究思路为：以难加工材料TC4钛合金为切削对象，从刀具材料制备与力学性能角度，优化制备适用于制作微铣刀的金属陶瓷刀具材质，评估金属陶瓷材质的力学性能与行为；从刀具结构设计与制造角度，设计ϕ0.1~ϕ1.0 mm微铣刀的空间几何结构，并进行结构创成研究；从切削受载角度，论证金属陶瓷材质能够满足微铣刀的切削性能要求；从应用角度，开展金属陶瓷微铣刀铣削TC4钛合金的切削性能研究。本研究能扩大和丰富微细刀具种类，为难加工材料微细结构加工制造提供刀具支持和工具保障，具有较好的学术研究与工程应用价值。