表面缺立方相梯度硬质合金研究进展  

Research Progress ofγ-Free Layer Gradient Cemented Carbide

作　　者：胡灿 陈冲 孙建清 潘昆明[1,2] 魏世忠 王长记[3] aHu Can;Chen Chong;Sun Jianqing;Pan Kunming;Wei Shizhong;Wang Changji(College of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471000,China;Longmen Laboratory Intelligent Manufacturing Basic Research Center,Luoyang 471000,China;National Local Joint Engineering Research Center for Wear Control and Forming Technology of Metal Materials,Henan University of Science and Technology,Luoyang 471003,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471000 [2]龙门实验室智能制造基础研究中心,河南洛阳471000 [3]河南科技大学金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003

出　　处：《稀有金属》2024年第10期1459-1474,共16页Chinese Journal of Rare Metals

基　　金：国家自然科学基金青年基金项目(51901070)资助。

摘　　要：表面确立方相梯度硬质合金是金属加工中最常用的涂层刀具材料之一,在精密加工中发挥着重要作用。梯度硬质合金基体是保证刀具稳定切削和良好服役寿命的关键因素之一。当其与Ti C,Ti N,Ti(C,N)和Al_(2)O_(3)等涂层结合使用时,由于涂层和基体之间热膨胀系数的差异,在二者结合过程中产生的热应力容易导致出现裂纹,从而降低刀具的切削性能和使用寿命。梯度硬质合金中的富粘结相表层可以提高合金表面的韧性,减少裂纹的产生,阻止裂纹的扩展。简单介绍了表面缺立方相梯度硬质合金梯度层的形成机制和常用的制备方法,总结了相图计算方法在梯度层组织和性能模拟中的应用,并从热力学数据库、动力学数据库和表征有效扩散系数的迷宫因子这3个方面论述了梯度层模拟技术的发展,阐述了梯度硬质合金原料粉末粒度、烧结工艺和合金组分(包括氮源、粘结相和二次碳化物)等对梯度层形成和合金性能等方面的影响,并对高性能涂层梯度硬质合金的未来研究方向进行了展望。Cemented carbide is a composite material prepared by powder metallurgy with refractory metal compounds(WC,TiC,TaC,NbC,etc.)as matrix and transition metal elements(Co,Fe,Ni,etc.)as binder phase.It is widely used in the fields of machine tool cutting tools,mining and rock drilling tools,tensile die and wear-resistant parts.Coated gradient cemented carbide is the most commonly used cutting tool and plays an important role in precision machining.When used in combination with Ti C,Ti N,Ti(C,N)and Al2O3 coatings,cracks often occur between coating and matrix due to the different thermal expansion coefficients,which affects the cutting performance and service life of the tool.The binder-rich andγ-free layer of the gradient cemented carbide can improve the toughness of the alloy surface,reduce the crack generation and prevent its propagation.In this paper,the formation mechanism and preparation method ofγ-free layer gradient cemented carbide are sketched,the application and development of phase diagram calculation method on the simulation of gradient layer formation are summarized,and the effects of powder size,sintering process and alloy compositions(including nitrogen source,binder phase and secondary carbide)on gradient layer formation and alloy properties are described in detail.The future research direction of gradient cemented carbide with high-performance coating has also been prospected.The formation of the gradient layer is based on the strong thermodynamic coupling between Ti and N atoms.During the sintering process,denitrification occurs at the surface of the cemented carbide.Ti(C,N)phase in the surface layer dissolves continuously into the liquid binder phase along with the outward diffusion of N and the inward diffusion of Ti through the liquid binder phase,resulting in the formation of theγ-free surface gradient layer.The formation of the gradient layer is affected by many factors.CALPHAD method can accurately describe the phase diagram thermodynamics and diffusion dynamics information of the multi-compon

关 键 词：梯度硬质合金 缺立方相 形成机制 制备方法 相图计算 

分 类 号：TG135.5[一般工业技术—材料科学与工程]