Cr/x/DLC复合涂层刀具切削铝硅合金切削性能研究

类金刚石(Diamond-Like Carbon,DLC)涂层刀具结合了基体强度高、韧性好以及涂层硬度高、耐磨性高的优点,可以有效降低刀-屑间摩擦,提高刀具切削寿命和加工效率。采用直流磁控溅射和等离子体辅助化学气相沉积(Plasma-Assisted Chemical Vapor Deposition,PACVD)法分别在硬质合金刀具基体上制备了单一DLC涂层、Cr/W-DLC/DLC复合涂层和Cr/CrN/DLC复合涂层。对比研究了具有不同Cr/x/DLC过渡层的DLC复合涂层硬质合金刀具加工过共晶结构铝硅合金AC9B的切削性能。研究结果表明:切削铝硅合金时,相对于无涂层硬质合金刀具,DLC涂层硬质合金刀具可以明显降低切削力和切削温度,并且具有更长的刀具切削寿命;Cr/W-DLC/DLC复合涂层硬质合金刀具的切削力最小,切削寿命最长。经显微分析,发现DLC涂层硬质合金刀具切削铝硅合金时的磨损机理主要是黏结磨损和硬质点磨损。     

TiSiC涂层钻头钻削CFRP/TC4钛合金叠层材料的研究

为解决碳纤维复合材料/钛合金叠层材料制孔刀具使用寿命短的问题,本文提出采用Ti Si C涂层来提高刀具耐用度,并研究了Ti Si C涂层钻头钻削碳纤维复合材料/钛合金叠层材料时的轴向力、刀具磨损和孔出口质量。结果表明,Ti Si C涂层刀具能减小钻削钛合金的轴向力,延长刀具寿命和改善孔出口质量,且制孔一致性良好,有利于提高钻孔质量和刀具寿命。     

Mapal公司推出新型PCD螺孔钻头

Mapal公司在2007年汉诺威EMO展览会上推出了名为”HP-Tap-Drill”的WWS新型PCD螺孔钻头。据称,由于该钻头在整个攻丝长度上均采用了PCD材料,因此与目前占据主要市场份额的金刚石涂层或非涂层整体硬质合金螺孔钻头相比,刀具寿命获得了大幅度提高。     

新型涂层刀片TZ15

<正> 西德维迪亚公司在世界上率先将涂层材料TiC 涂复于硬质合金刀具上,从开始销售到现在,已有二十年的时间。由于涂层刀具同时具有硬质合金基体材料的高韧性和表面涂层的高     

陶瓷刀具材料的新进展与应用（上）

切削加工生产率和刀具寿命的高低、加工成本的多少、加工精度和加工表面质量的优劣等，在很大程度上取决于刀具材料的合理选择。目前应用的刀具材料主要有金刚石、立方氮化硼、陶瓷、TiC（N）基硬质合金（金属陶瓷）、硬质合金、高速钢及各种涂层刀具。它们各有各自的特点，适应不同的工件材料和不同的切削速度范围。     

涂层硬质合金刀具在高强度钢加工中的应用

一、涂层硬质合金在中国的发展在中国，涂层硬质合金的研究始于1972年，在80年代中期形成大批量生产能力。目前，国内多采用CVD方法在硬质合金上进行涂层。株洲硬质合金厂以瑞典和瑞士的涂层设备，可提供YB系列、CN系列及CA系列的涂层刀片。自贡硬质合金厂用美国的涂层设备，可提供ZC系列涂层刀片。北京钢铁研究总院和成都工具所则以自制设备，也能提供涂层刀片产品。刀片的基本材料，有的是采用普通P、M或K类硬质合金，有的是采用特殊基体。涂层材料有TiC、TiN、Ti（C，N）、Al2O3、Ti（N，B）和HfN等。中国涂层刀片的切削性能…     

硬质合金钻头修磨与涂层技术的应用探索

针对HOWO被动锥齿轮加工中硬质合金钻头的使用,讨论了硬质合金钻头各相关参数对加工性能的影响,并且对各种不同的涂层材料进行了使用寿命对比试验。通过对刀具相关参数的优化,重磨技术和最新涂层技术的应用,将钻头使用寿命提高了数倍,明显降低了刀具成本。     

硬质合金刀具高速车削钛合金的切削性能研究

采用单因素试验法,用未涂层硬质合金刀具和TiAlN涂层硬质合金刀具对Ti-6Al-4V钛合金进行了高速干车削试验,通过对切削过程中切削力、刀具寿命、切削温度以及加工表面粗糙度的分析,得出了两种刀具高速干车削钛合金的切削性能,为钛合金高速切削刀具的设计提供了试验依据。     

[刀具及切削工艺]高速铣削中TaC（NbC）对硬质合金刀具磨损性能的影响

针对航空航天钛合金加工时硬质合金刀具磨损过快的难题，制备了主元素一致、微量合金碳化物TaC（NbC）含量不同的两种WC-Co基硬质合金材料。采用高温维氏硬度计检测两种材料的高温硬度和高温断裂韧性，并制备相同几何参数的立铣刀对钛合金TC4进行铣削加工试验。试验结果表明：在硬质合金中添加微量合金碳化物TaC（NbC），可以同时提高材料的高温硬度和高温断裂韧性,在相同的切削条件下，添加微量合金碳化物TaC（NbC）的硬质合金立铣刀比未添加微量合金碳化物的立铣刀耐磨性更好，刃口断裂裂纹更少，刀具使用寿命更长，更适合航空航天钛合金材料的高速铣削加工。     

类金刚石刀具涂层研究进展

类金刚石(DLC)涂层因其优良性能在有色金属和复合材料等材料的切削刀具表面广泛应用。基于DLC涂层刀具的使役性能,详述了DLC刀具涂层制备方法,主要包括离子束沉积法、磁控溅射法、电弧离子镀法和等离子体增强化学气相沉积法;阐述了不同类型DLC涂层材料的结构特征与性能特点,总结了DLC涂层刀具存在的膜—基结合力差、涂层厚度低和热稳定性差等问题及其优化方向;结合不同材料的加工特点,介绍了DLC涂层刀具在有色金属以及复合材料等材料加工中的应用情况;展望了DLC涂层未来的发展方向。     

真空阴极电弧沉积（Ti,Al）N薄膜的应用研究

为了提高TiN涂层刀具的耐磨性,采用钛铝合金靶,以真空阴极电弧沉积法制备了（Ti,Al)N涂层,对膜层形貌成分,组织结构及硬度进行了测试及研究,并试验了（Ti,Al)N涂层高速钢钻头及YG6硬质合金刀具的使用寿命,结果表明：（Ti,Al)N涂层硬度高达HV0．1,15,3700,（Ti,Al)N涂层使高速钢钻头及YG6硬质合金刀具的使用寿命显著提高。     

Comparative assessment of the mechanical and electromagnetic surfaces of explosively clad Ti–steel plates after drilling process

The present work pertains to the analysis of surface topography of explosively clad material such as titanium plated steel in drilling process. The study was conducted for different types of indexable insert drills with different configuration of the tool coatings and for WC-Co drill tool. In this context, surface topography of the drilled holes especially in the region of contact area was analyzed. Metrological analysis was performed using stylus-based and optical profilometry. In this paper the differences between mechanically and electromagnetically measured surfaces are highlighted. It has been observed that the parameters of the surface topography are dependent upon the type of layers of the clad and the type of drill.     

Investigating the feasibility of DLC-coated twist drills in deep-hole drilling

The ideal coating for twist drills used to drill deep holes should have both a high hardness and a smooth surface. The latter property is considered to ease chip evacuation through the drill’s chip flutes and, therefore, reduces the risk of chip clogging and possible premature drill fractures. For this reason, diamond-like carbon (DLC) appears to be a well-suited type of coating. This paper presents the results of cutting tests using DLC-coated HSS and cobalt-HSS twist drills when drilling deep holes of diameter 1.5 mm into plain carbon steel. Their capability to extract swarf from the borehole as well as their tool lives were investigated and compared to uncoated and TiN- and MoS₂-coated drills. Although the DLC-coated drills showed a very good swarf disposal capability, they did not exhibit a longer tool life when compared to off-the-shelf drills.     

Evaluation of the performance of coated and uncoated carbide tools in drilling thick CFRP/aluminium alloy stacks

This paper aims to establish the wear mechanisms of coated and uncoated tungsten carbide drills when drilling carbon fibre reinforced plastics (CFRP)/aluminium alloy (Al) stacks. During the drilling experiments, thrust forces were measured. A scanning electron microscope (SEM) and a numerical microscope, provided with a scanning device, were periodically used to analyse tool wear mechanisms and to measure wear progression of the tool cutting edges. For both coated and uncoated drills, abrasion was the dominant tool wear mechanism, affecting the entire cutting edges. Higher wear was observed on uncoated tools which caused a significant increase in thrust force during drilling both Al and CFRP materials. The influence of these phenomena on the quality of the holes and on the generated roughness was also discussed.     

HIGH THROUGHPUT DRILLING OF TITANIUM ALLOYS

The experiments of high throughput drilling of Ti-6Al-4V at 183 m/min cutting speed and 156 mm3/s material removal rate using a 4 mm diameter WC-Co spiral point drill are conducted. At this material removal rate, it took only 0.57 s to drill a hole in a 6.35 mm thick Ti plate. Supplying the cutting fluid via through-the-drill holes and the balance of cutting speed and feed have proven to be critical for drill life. An inverse heat transfer model is developed to predict the heat flux and the drill temperature distribution in drilling. A three-dimensional finite element modeling of drilling is con-ducted to predict the thrust force and torque. Experimental result demonstrates that, using proper machining process parameters, tool geometry, and fine-grained WC-Co tool material, the high throughput machining of Ti alloy is technically feasible.     

Surface Texturing of Drill Bits for Adhesion Reduction and Tool Life Enhancement

Properly designed micro-scale surface textures can have positive impact on adhesion reduction and lubrication enhancement, which can lead to lower friction and improved performance of a contact interface. The present study aims to utilize this function of textures to reduce the adhesion between a drill and a workpiece. In this study, rectangular surface textures were generated on the margins of drill bits using a diode-pumped Nd:YVO₄ picosecond laser with a wavelength of 532 nm. Two designs were created in which the textures covered approximately 10 and 20 % of the margin surface area. Textured drills were tested by drilling a series of holes in a titanium plate while recording cutting forces, and the results were compared with the performance of baseline samples. Thermographic heat profiles and visual inspections of the drills were taken at increments of 5 and 10–15 holes, respectively. The comparison demonstrated an encouraging improvement in drill bit life as judged by the number of holes drilled before failure. Textured drills were found to reduce adhesion of titanium chips on the drill margins. This work has demonstrated the potential of texturing to significantly improve the lifetime of drill bits and similar cutting tools.     

麻花钻磨损特性的研究

通过对调质合金结构钢的大量钻削试验,研究了麻花钻磨损区的图形特征和磨损机理以及钻头失效与磨损图形参数、钻头切削寿命与钻削速度的关系。结果表明,麻花钻的磨损具有非线性特征,钻头转角和主刀刃及横刃区有两个显著不同的磨损区,随钻削速度的提高,这两个磨损区的特征差异及磨损带宽度之比明显增大。在钻削速度较低、钻头失效时,两个磨损区为较均衡的磨粒磨损和粘结磨损;钻削速度较高时,转角区剧烈的粘结磨损和氧化磨损使钻头加快失效,而主刀刃及横刃上的磨损却很小。受此影响,麻花钻的磨钝标准、耐用度问题较为复杂,钻头的寿命（Ｔ）－速度（Ｖ）曲线的泰勒特性范围很窄。     

Dry and minimum quantity lubrication high-throughput drilling of compacted graphite iron

This research studies the sustainable and high-throughput drilling of compacted graphite iron (CGI), a high strength, lightweight material for automotive powertrain applications. CGI drilling experiments were conducted using a 4 mm diameter coated carbide drill at 26.5 mm/s feed rate. In two repeated tests under three lubrication conditions: dry, dry with through-the-drill compressed air, and through-the-drill minimum quantity lubrication (MQL), the drills were able to produce a maximum of 1,740, 3,150 and 2,948 holes, respectively, before the breakage of the drill. The Joule–Thomson effect due to the expansion of high pressure air from through-the-drill holes at the drill tip, chip shape, chip size and chip speed are investigated. Flank wear of the drill cutting edge is measured and results are correlated to drill life. Results indicate that dry machining of CGI is technically feasible. Chip evacuation and advanced tool cooling are important factors that affect drill life for high-throughput sustainable dry drilling of CGI.