用PCBN刀具车削硬质合金

硬质合金模具硬度高,常用磨削、电火花或超声波等特种加工方法进行加工,这些加工方法效率均较低。随着超硬材料刀具技术的不断发展,相继产生复合超硬材料刀具,用以车削加工硬质合金材料,这种刀具材料既有超硬材料的高硬度,又有硬质合金刀片基体的抗弯强度,所以可车削硬质合金的模具。目前复合超硬材料刀具有复合聚晶金刚石（PCD）刀具和复合聚晶立方氮化硼（PCBN）刀具两种。一、PCBN刀具车削硬质合金的有关数据     

PCD刀具在非金属材料加工中的应用

1 引言 PCD刀具泛指用人造复合聚晶金刚石片(简称PCD)制造的切削刀具.人造复合聚晶金刚石片是将聚晶金刚石微粉通过高温高压烧结压制在硬质合金基体上形成的硬质合金-金刚石复合材料.用其制作的PCD刀具既具有金刚石的高硬度、高强度同时又具有硬质合金的韧性.     

人造金刚石刀具加工有色金属的研究

对人造金刚石刀具加工有色金属的切削性能进行了试验研究。结果表明，目前国产PCD金刚石刀具在加工铝硅合金时的切削性能与国外同类刀具相差不大，符合使用要求；并且得出了CVD金刚石刀具在加工某些有色金属时的切削性能优于硬质合金刀具的结论。     

超硬刀具在加工硬脆难加工材料中的应用

一、前言某些机器零件采用了难加工材料制造，其中包括一些高硬度的脆性材料。在这个加工领域中，超硬刀具能够发挥很大的作用。除天然金刚石外，人造金刚石在近年来已得到了更为广泛的应用。人造金刚石是以石墨为原料，加入催化剂，经过高温、高压制成单晶金刚石细粉，可用作磨料。再用金刚石细粉加入粘结剂，经过又一次高温、高压工艺，从而可以制成聚晶金刚石刀片或其它制品。用类似的工艺，亦可制成以硬质合金作为基底的金刚石复合刀片（PCD）。另一种最新的方法，是用化学气相沉积（CVD）工艺，在硬质合金或陶瓷刀片上涂覆一层金刚…     

钛合金切削加工中刀具寿命和刀具磨损的研究

钛合金是典型的难加工材料,提高钛合金的加工效率和刀具寿命是急需解决的问题。本文选用Ti-6Al-4V作为工件材料,选取两种不同的硬质合金和一种聚晶金刚石(PCD)作为刀具材料,对切削加工中刀具寿命和刀具磨损进行了试验研究。研究结果表明:PCD刀具寿命明显高于硬质合金刀具,在高速下优势尤其明显;两种硬质合金刀具低速下主要是粘结磨损,高速下主要是粘结磨损、扩散磨损和氧化磨损;PCD刀具主要是微崩刃和石墨化引起的沟槽磨损。     

金刚石刀具的正确使用

金刚石刀具是指用天然单晶金刚石（ND）及性能与之相近的人造金刚石（PCD）作成切削部分的刀具。用金刚石刀具加工铜、铝等有色金属和非金属耐磨材料时特别有效,其切削速度可比硬质合金高一个数量级 （例如铣削铝合金的切削速度为3000-4000m／min,高的甚至可达7000m／min）,刀具寿命比硬质合金高几十、甚至几百倍。     

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。     

晶粒细化对金刚石涂层刀具切削性能的影响

金刚石涂层具有高硬度、低摩擦系数、高耐磨性和高导热性能。本文着重介绍了金刚石涂层刀具的发展动向及现状,并通过金刚石涂层刀具的切削试验表明了金刚石涂层刀具的使用寿命明显高于未涂层的硬质合金刀具,采用金刚石涂层刀具进行切削可以获得更高的表面加工质量和生产率。     

CVD金刚石厚膜刀具切削性能的试验研究

分析了CVD金刚石厚膜刀具材料的性能特点 ,对CVD金刚石厚膜车刀进行了精密切削和难加工复合材料切削试验 ,结果表明 :CVD金刚石厚膜刀具加工铝合金的表面粗糙度可达Ra0 0 5 μm ;切削难加工复合材料时刀具耐磨性和使用寿命明显优于硬质合金刀具、PCBN刀具和PCD刀具     

高性能新型金刚石薄膜刀具

金刚石薄膜刀具是90年代前后研制成功的一种新型刀具,其特点是:切削速度高,切削深度和进给量大,生产率高;切削力小,温升低,加工精度高可用于高速微切削精加工中;耐磨性好,耐用度是普通硬质合金刀具的50～100倍。目前它应用在有色合金、复合材料和许多非金属材料的切削加工中,正与多晶金刚石(polycrystalline diamond——PCD)、硬质合金和陶瓷刀具争夺市场。日美两国已开发成功各类金刚石薄膜车刀(指铣刀、钻头等刀具)。美国在短期内对这类刀具的销售额就达到7500万美元。金刚石薄膜是通过化学气相沉积(CVD)方法,使金刚石晶体沉积在碳化钨或陶瓷基底上,其厚度一般不大于50μm。目前的CVD方法以微波辅助CVD系统应用最多。该系统的金刚石薄膜沉积原理是:将氢气     

Environmentally conscious hard turning of cemented carbide materials on the basis of micro-cutting in SEM: stressing four kinds of cemented carbides with PCD tools

Environmentally conscious hard turning and technology has placed more importance on the machining process. In this research, the possibility of environmentally conscious hard turning of cemented carbides was studied. The effects of cutting methods of dry and wet (vegetable oil mist, and mineral oil) and work material on cutting resistance and wear characteristics of cutting tools were experimentally investigated. The turning and micro-cutting process in SEM was carried out by using four kinds of tungsten carbides with the PCD cutting tools. Specifically, an emphasis was put on the effect of WC and Co additives in four kinds of cemented carbides on machinability and tool wear characteristics. The tool wear width and the cutting resistances were measured, and the worn flank was observed.     

Environmentally conscious hard turning of cemented carbide materials on the basis of micro-cutting in SEM (2nd report): stress turning with three kinds of cutting tools

Environmentally conscious hard turning and technology have placed increasing importance on the machining process. Cutting fluids have a significant impact on the environment, thus numerous research works are being performed to minimize their use. However, tool wear is very severe in hard turning cemented carbides without the use of cutting fluids. In this research, the effects of dry and wet cutting methods (vegetable oil mist and mineral oil) and tool material on cutting resistance and wear characteristics of cutting tools were experimentally investigated to study the possibility of creating an environmentally conscious hard turning of cemented carbides. Mist and wet cutting of the cemented carbides using poly-crystalline diamond (PCD) cutting tools were adopted to investigate how tool wear on the basis of micro-cutting in the Scanning Electron Microscope (SEM) can be reduced. Additionally, the poly-crystalline cubic boron nitride (PcBN) and the usual cBN cutting tools were compared with the PCD cutting tools. This paper was presented at the 9^th Asian International Conference on Fluid Machinery (AICFM9), Jeju, Korea, October 16–19, 2007.recommended for publication in revised form by Associate Editor Dae-Eun Kim HEO Sung Jung was born in Busan, R. O. K., in 1958. He received the Ph.D. in Mechanical Engineering from Osaka University, Osaka, Japan. He is a Full Professor of Mechanical Engineering at Doowon Technical College, Ansong -si, Gyonggi-do, Republic of Korea. His current research interests are in the areas of cutting of difficult-to-cut materials, environmentally conscious machining and cutting tool design.     

White layer formation and hardening effects in hard turning of H13 tool steel with CrTiAlN and CrTiAlN/MoST-coated carbide tools

White layers are hard, brittle and normally associated with a tensile stress and hence the ability to reduce the fatigue life of machined components. Several authors have reported the formation of white layers on components after turning processes by using CBN/PCBN and ceramic cutting tools. However, there are hardly any studies that have reported on white layer formation for new and low-cost-coated carbides. The study in this paper was conducted to determine the effect of CrTiAlN and CrTiAlN+MoST and high cutting speeds on white layer formation in machining tool steel. H13 tool steel (57 HRC) was examined after turning at a conventional and high cutting speed. Coated tools resulted in lower workpiece and tool temperatures. Hence coated tools resulted in reduced and also more homogeneous hardening effects compared to the uncoated tool. In addition, the higher cutting speed produced negligible white layers. Thus, the paper elucidates on the benefits of coatings on surface hardening in conventional and high speed machining.     

Performance analysis of cryogenically treated coated carbide inserts

Cryogenic treatment has been acknowledged in several researches as a means of extending the tool life of many cutting tools. Studies on cryogenically treated (CT) cutting tools show microstructural changes in the material that can influence the life of the tools significantly. Tungsten carbide cutting tools are now commonly used in the industry. So far, only a few detailed studies were carried out pertaining to the cryogenic treatment of carbides. This paper primarily reports and analyses the various performances of CT coated carbide inserts and untreated (UT) coated carbide inserts in turning of nodular cast iron. From the results, it can be seen that CT coated carbide inserts exhibit better performance based on the surface roughness of the work specimen, power consumption, and flank wear than the UT ones. The scanning electron microscope analysis is carried out for the worn out CT and UT coated carbide inserts to predict the wear resistance.     

Analysis of tool wear patterns in finishing turning of Inconel 718

This paper focuses on the analysis of tool wear mechanisms in finishing turning of Inconel 718, one of the most used Ni alloys, both in wet and dry cutting. Cemented carbides, ceramics and CBN tools are suitable for machining Ni alloys; coated carbide tools are competitive for machining operations of Ni alloys and widely used in industry. Commercial coated carbide tools (multilayer coating TiAl/TiAlN recommended for machining Ni alloys) were studied in this work. The feasibility of two inserts tested for dry cutting of Inconel 718 has been shown in the work. Experimental test were performed in order to analyze wear patterns evolution. It was found great influence of side cutting edge angle in tool wear mode.     

Machining of austenitic stainless steels using CVD multi-layer coated cemented carbide tools

This paper presents the results of experimental work in dry turning of austenitic stainless steels (AISI 304 and AISI 316) using CVD multi-layer coated cemented carbide tools. The turning tests were conducted at four different cutting speeds (120, 150, 180 and 210 m/min) while feed rate and depth of cut were kept constant at 0.16 mm/rev and 1 mm, respectively. The cutting tools used were TiC/TiCN/TiN and TiCN/TiC/Al₂O₃ coated cementide carbides. The influences of cutting speed, cutting tool coating top layer and workpiece material were investigated on the machined surface roughness and the cutting forces. The worn parts of the cutting tools were also examined under scanning electron microscope (SEM). The results showed that cutting speed significantly affected the machined surface roughness values. With increasing cutting speed, the surface roughness values decreased until a minimum value is reached beyond which they increased.     

硬质合金材料及其涂层对不锈钢加工中刀具边界磨损的影响

硬质合金刀具在不锈钢加工中,其刀具耐用度主要是取决于后刀面边界磨损而不是主切削刃后刀面的平均磨损量。为了提高刀具耐用度,就必须减小后刀面边界磨损。本文对奥氏体不锈钢（ＳＵＳ３０４） 在车削及铣削加工中,采用Ｍ２０ 、Ｋ２０ 和Ｚ２０ 材料以及ＴｉＮ、Ｔｉ（Ｃ,Ｎ） 和（Ｔｉ,Ａｌ）Ｎ 物理涂层（ＰＶＤ）的硬质合金刀具进行了耐边界磨损的研究     

高精度圆体成形车刀的CAD/CAM系统

研究了高精度圆体成形车刀优化设计的数学模型，介绍了用VB语言开发的高精度圆体成形车刀的CAD／CAM子系统的构成及其主要模块的功能该系统可由工件零件图直接生成加工该工件的高精度圆体成形车刀的零件图及刀具廓形的数控线切割加工程序，同时还能通过仿真检验所设计的刀具廓形及其加工程序代码的正确性。