新型复相陶瓷刀具材料的研制及切削可靠性研究

研制成功了国内外尚属空白的新型陶瓷刀具材料——碳化硅晶须(SiCw)增韧和碳化硅颗粒(SiCp)弥散补强Al_2O_3陶瓷刀具材料JX-2系列,其硬度为93.5～94.8HAA,抗弯强度为650～750MPa,断裂韧性为7.5～8.5MPa·m~(1/2),并且具有导热性好和成本低等优点。 对原料组分和热压烧结工艺进行了优化设计;证实了晶须和颗粒具有增韧补强的协同作用,根据能量耗散理论,建立了晶须桥联、拔出、裂纹偏转和微裂纹增韧的理论模型;详细研究了该陶瓷刀具材料的界面力学行为及其与材料力学性能的关系,研究了材料的界面作用机理;建立了Al_2O_3/SiCw/SiCp系陶瓷刀具材料界面结合强度L_f和断裂韧性K_(IC)的关系模型,据此可以实现复合陶瓷刀具材料的组分优化设计,缩短复合材料的研制时间。 深入研究了新型复相陶瓷刀具材料的切削性能及其磨损破损机理,并对刀具热磨损和热破损的机理进行了强激光热模拟;研究了该刀具材料力学性能、界面结合强度和刀具破损寿命的随机性,它们的分布规律均较好地服从威布尔分布,首次提出了用界面结合强度评价JX-2陶瓷刀具破损可靠性的新方法。     

现代陶瓷刀具材料

文章回顾了现代陶瓷刀具材料的发展，强调了显微结构对刀具材料的机械性能和使用性能的影响，全面介绍了各种陶瓷刀具材料的组织和性能特点以及在高速切削加工时如何正确地选择和使用陶瓷材料。     

优质陶瓷刀具材料

陶瓷是未来的最新一类刀具材料,其潜力在于高速精加工操作范围宽以及对于难加工材料亦具有切削加工速率。陶瓷刀具材料的发展部分地归于70年代汽车、燃气透平和其他高温结构材料应用所新开发的高温结构陶瓷技术。优质陶瓷即氧化铝、部分稳定氧化锆(PSZ)、碳化硅及氮化硅,但是块状PSZ因硬度有限(努氏硬度～1500Kg/mm~2),不能用作机加工的切割刀具。此外,碳化硅也     

基于切削可靠性的新型陶瓷刀具材料的研制

建立了切削可靠性和刀具力学性能之间的关系模型,根据切削可靠性和断裂韧性的要求设计并制备出了颗粒和晶须协同增韧的陶瓷刀具JX-2,其力学性能与晶须增韧陶瓷刀具(JX-1)相当,但成本低,且抗扩散磨损的能力强.将JX-2、JX-1和硬质合金刀具YG6X进行对比切削电铸纯镍实验,JX-2的切削速度最高,磨损寿命最长,其抗磨损能力最强,是加工纯镍或高镍合金等材料的理想刀具.     

陶瓷刀具在机匣加工中的应用

陶瓷刀具是现代金属切削加工中的一种新型材料刀具。其切削加工效率为普通硬质合金的6¹0倍,本文主要通过陶瓷刀具在加工中的应用介绍陶瓷刀具的切削特点及应用。     

石墨烯纳米片增韧Al2O3基纳米复合陶瓷刀具材料

以石墨烯纳米片作为增强相,采用热压烧结工艺制备石墨烯纳米片增韧Al_2O_3基纳米复合陶瓷刀具材料。进行石墨烯纳米片分散实验,研究石墨烯纳米片添加量对刀具材料断裂韧度、抗弯强度和硬度的影响,观察其微观结构和形貌。结果表明:聚乙烯吡咯烷酮(PVP)为石墨烯纳米片的优选分散剂,当PVP添加量为石墨烯纳米片质量的60%时,分散效果最佳;当石墨烯纳米片添加量为0.75%(体积分数)时,刀具材料的断裂韧度和抗弯强度分别达到7.1MPa·m^1/2和663MPa,与未添加石墨烯纳米片的组分相比分别提高了31%和15%;石墨烯纳米片呈卷曲状结构弥散分布于基体材料中,其增韧机理为石墨烯纳米片拉断、拔出和裂纹偏转。与未添加石墨烯的刀具相比,添加石墨烯纳米片的刀具的主切削力、切削温度和前刀面摩擦因数明显降低,表现出良好的减摩、耐磨性。     

粉末表面涂层陶瓷的硬质合金刀具材料

使用溶胶－凝胶法在硬质合金粉末表面涂覆了一层氧化铝陶瓷,涂层粉末经热压烧结后,制得一种新型的涂层刀具材料,这民具材料的耐磨性与陶陶瓷材料接近,并且具有较高的强度和韧性,在切削高硬度材料时表出良好性能,具有广阔的应用前景。     

新型液压缓冲汽缸活塞杆设计及新工艺浅析

现有缓冲汽缸活塞杆为分体组合,不仅在使用过程中易松动、损坏,而且加工繁琐,材料浪费严重,工作效率低。通过结构和工艺改进,既降本增效,又提高产品的质量和使用寿命,同时新型陶瓷刀具的应用也提高了产品的加工效率,新刀具可推广应用,极大的提高了车削工件的表面光洁度。     

多相复合陶瓷刀具材料的设计与制备

陶瓷材料的多相复合与计算机辅助设计是２１世纪先进陶瓷材料的重要发展趋势,章采用理论与实验相结合的方法,建立了多相复合陶瓷刀具材料力学性能与材料组分之间关系的数学模型,采用计算机辅助优化设计技术求得材料的最优组分,在此基础上,利用热压技术制得一种Ａl2O3-SiC-(W,Ti),Ｃ多相复合陶瓷刀具材料,该材料具有良好的综合力学性能。     

硬质合金粉末表面涂层陶瓷的刀具材料研制

用溶胶－凝胶法在硬质合金粉末表面涂覆了一层氧化铝陶瓷，涂层粉末经热压烧结后制得一种新型的涂层刀具材料。这种刀具材料的耐磨性与陶瓷材料接近，并且具有较高的强度和韧性，在切削高硬度材料时表现出良好性能，具有广阔的应用前景。     

新型陶瓷刀具材料的热应力分析

运用有限元方法计算了梯度功能陶瓷刀具ＦＧ－２内的热应力,计算结果表明,在高速切削条件下,梯度功能陶瓷刀具内的热应力明显小于普通陶瓷刀具;同时进行的切削实验也表明在高速切削的条件下,ＦＧ－２的破损寿命明显好于ＳＧ－４．说明梯度功能陶瓷刀具适应于高速切削．     

Effects of geometric angle and cutting speed on cutting forces and tool wear of ceramic cutting tools during peripheral up-milling of high-density fiberboard

In this paper, cutting forces and tool wear of ceramic cutting tools are investigated by up-milling high-density fiberboard under different geometric angles and cutting speeds. The results show that tangential force (F_t) and normal force (F_r) decrease with the increase of rake angle. The values of F_t and F_r at the higher speed cutting condition are lower than that at the lower speed condition. The flank wear (VB) declines with increased clearance angle and decreased cutting speed. The tool wear patterns observed on the ceramic cutting tools are pull-out of grain, cracking, tipping, and flanking. Abrasive wear and adhesive wear are the main mechanisms of the ceramic cutting tools. In all, on the premise of guaranteeing the ceramic cutting tools’ strength, the ceramic cutting tool with a bigger rake angle and clearance angle is advisable in high-density fiberboard machining, in terms of lowering the energy consumption and production cost required for machining.     

陶瓷刀具切削304不锈钢时的磨损性能

采用Ｓｉ３Ｎ４陶瓷刀具切削Ｔｉ基陶瓷，ＹＴ１５硬质合金和高速钢四种刀具对３０４奥氏体不锈钢进行了切削试验，比较各种刀具的耐磨性能，并且用ＳＥＭ，ＥＤＸ等对刀具的磨损表面进行分析。     

Research Progress of Laminated Composite Ceramic Cutting Tools

The design of the lamination structure based on bionic shell pearl layer is a successful method for toughening ceramics. Lamination with strong bonding interfaces is used to improve the mechanical property and low fracture toughness of ceramic cutting tools. Based on the idea of demand–design–preparation–analysis–failure, the development and research progress of laminated ceramic tools are reviewed herein. The research status of design, interlayer diffusion reaction, residual stress, toughening mechanism, and crack propagation path of the biomimetic laminated ceramic composite tool materials is mainly introduced. The major topics of current research include the creation of material systems, the evolution of microstructure, and the assessment of macroscopic mechanical properties. The entire mechanical properties of laminated ceramic tools are significantly influenced by the multicomposition design of the ceramic material system and the optimization design of structural parameters of layer number and layer thickness ratio. However, the research on the practical cutting application of laminated ceramic tools is limited. Cutting tool wear characteristics vary between laminated and homogeneous ceramic tools. The development of useful laminated ceramic cutting tools can greatly benefit from the study on failure mechanisms of laminated ceramic tools.     

聚焦离子束技术制造金刚石切削刀具的研究

概述了基于聚焦离子束（Focused Ion Beam,FIB）加工技术制备金刚石切削刀具的相关研究进展,并介绍了金刚石刀具在超精密加工领域的研究背景及其制造现状。作为一种先进的微纳制造技术,聚焦离子束已在微尺度金刚石刀具制造研究中发挥了重要作用。针对金刚石刀具的刃口半径、刃形精度等核心参数,国内外相关研究者开展了聚焦离子束制造方法与工艺优化研究,实现了高质量刀具的制造,聚焦离子束加工可获得刃口半径为15～22nm的金刚石刀具制造。从微观切削基础和微纳光学元件制造两个角度,论述了聚焦离子束制造金刚石刀具的应用研究进展,介绍了其在纳米切削机理、微纳尺度光学元件制造中的应用。最后从提高FIB制造效率、应用研究拓展等角度,对该领域未来的发展进行了展望。     

Efficiency of cutting tools equipped with cBN-based polycrystalline superhard materials having vacuum-plasma coating

The paper deals with the studies of improving the efficiency of cutting tools equipped with cBN-based polycrystalline superhard materials by a vacuum-plasma coating. It has been shown that the tools with coatings are characterized by an increased reliability at the stage of running-in and longer life, and allow using higher cutting parameters.     

Identification of machining features based on available resources of cutting tools

In research on machining feature recognition, the problems of interacting features and availability of cutting tools are considered two major obstacles for developing industrial applications. In this research, a new machining feature recognition approach is developed to address these problems. In this work, a new concept called cutting mode is introduced to associate generic machining surfaces and cutting motions. In the feature recognition process, the machining surfaces of a part are first mapped to cutting modes, and these cutting modes are further mapped to available cutting tools. Among all the created candidate machining processes, heuristic rules are employed to identify the optimal solution that requires the minimum number of setups. When a number of machining surfaces are associated with a cutting tool in the same setup, these surfaces are grouped as a machining feature. Therefore the interacting features are recognised by the different cutting tools to produce these features. A database of available cutting tools is used to avoid the identification of features which cannot be machined in a machine shop. Three mechanical parts with interacting features are selected in the case studies to demonstrate the effectiveness of the developed approach.