汽车发动机缸体镗孔用CNB刀具的国产化试验

在引进汽车发动机生产线上对高速半精镗,精镗缸孔的ＣＢＮ刀具进行了切削对比试验。结果表明,通过改善切削刃形状,国产ＣＮＢ刀具可以替代进口ＣＢＮ刀具。     

帕莱克创新型精密模块化镗刀系列

帕莱克有限公司是世界上刀具及刀具预调仪设计与制造的领导者,目前拥有创新的镗孔类刀具产品设计团队与制造生产线,产品包括新的精密精镗刀具、双刃粗镗刀具、大孔径镗刀刀具和小孔径精镗刀具。精密精镗刀具特点:精镗头具备最小刻度2μm(直径)的精密调节刻度盘;带有内冷却液导向孔,使冷却液直接到达切削刃;通过加长型刀夹可以改变一只精镗头镗孔范围。     

GCr15轴承钢的切削温度

为了探讨ＰＣＢＮ 刀具的切削性能,制定出ＰＣＢＮ 刀具切削淬硬轴承钢的最佳切削规范,对不同切削速度、进给量及材料硬度下的切削温度的变化规律进行了试验,得出当加工硬度高于５０ ＨＲＣ时的材料时,选择０．２５ ｍ ｍ以上的切削深度有利于降低切削温度,提高刀具寿命。附图４幅,表２个,参考文献３篇     

高效的精镗刀具

镗孔是在机械加工中一个重要的环节。众所周知,对于精镗刀具的要求主要是保证尺寸精度的同时能够改善表面粗糙度,同时可以在较短的切削时间内达到很高的切削速度。因此,精镗加工无疑也是一种要求很高的切削加工。上海松德数控刀具通过长时间的努力,现在已可提供一套经实践验证的镗削刀具系统,这种新推出的系统所具有的高精度调节装置,使直径的精调幅度可达到0．001mm。     

PCBN刀具的切削性能

综合实际数据、曲线介绍了ＰＣＢＮ刀具在淬硬钢、铸铁及有色金属等材料切削加工中的切削特性及其在硬态切削、干式切削、高速切削等加工技术中的应用。同时也介绍了ＰＣＢＮ刀具的加工表面质量。     

PCBN刀具应用于先进切削工艺研究

介绍了ＰＣＢＮ刀具的特点、性能及高速、超高速切削、硬态切削、干式切削等先进切削工艺的特点和优越性,并用实际数据说明ＰＣＢＮ是适合于上述先进切削工艺方法的理想刀具材料,具有重要的应用价值和意义。     

铝活塞肖孔可调镜面镗刀

说明:1.刀具特点:(1)刀片上有四种不同的刀刃,分别起着镗、精镗、挤压作用,是切削加工与挤压加工相结合的刀具。(2)刀体上开有槽子,通过锥螺丝调节刀具外径,其范围见表。     

PCBN刀具的切削性能

综合实际数据、曲线介绍了ＰＣＢＮ刀具在淬硬钢、铸铁及有色金属等材料切削加工中的切削特性及其在硬态切削、干式切削、高速切削等加工技术中的应用。同时也介绍了ＰＣＢＮ刀具的加工表面质量。     

粗镗浮镗滚压组合加工

介绍在深孔镗床上一次进给完成深孔油缸的粗镗、精镗、滚压的改进措施 ,并介绍其刀具结构设计、切削参数和加工特点。     

PCBN刀具精车高硬度轴承钢的合理切削速度

本文考察了切削速度对ＰＣＢＮ刀具寿命、切削温度、切削力和工件表面粗糙度的影响，总结出ＰＣＢＮ刀具切削高硬度轴承钢时合理的切削速度使用范围。Ｘ射线衍射议的测量结果表明，用ＰＣＢＮ刀具加工的工件表面存在残余压应力．     

Modelling of CBN tool crater wear in finish hard turning

The wear of cubic boron nitride (CBN) cutters, commonly used now in the finish turning of hardened parts, is an important issue that needs to be addressed for hard turning to be a viable technology due to the high costs of CBN cutters and the down-time for tool change. Chipping and tool breakage, which lead to early tool failure, are both prone to take place under the effect of crater wear. The objective of this study is to develop a methodology to model the CBN tool crater wear rate to both guide the design of CBN tool geometry and optimise cutting parameters in finish hard turning. First, the wear volume losses due to the main wear mechanisms (abrasion, adhesion, and diffusion) are modelled as functions of cutting temperature, stress, and other process attributes respectively. Then, the crater wear rate is predicted in terms of tool/work material properties and cutting configuration. Finally, the proposed model is experimentally validated in finish turning of hardened 52100 bearing steel using a low CBN content insert. The comparison between the prediction and the measurement shows reasonable agreement and the results suggest that adhesion is the main wear mechanism over the investigated range of cutting conditions .     

感应钎焊温度对立方氮化硼砂轮磨削性能的影响

利用超高频感应钎焊在不同钎焊温度条件下制备立方氮化硼(CBN)砂轮,采用扫描电子电镜（SEM）和能量分散谱仪（EDS）对磨粒表面新生化合物进行观察与分析,并通过与电镀CBN砂轮进行比较,对感应钎焊CBN砂轮的磨削性能进行评价。结果表明：CBN磨粒界面新生化合物主要组成元素有N、B、Ti三种,活性元素Ti发生扩散并与N和B发生化合反应;当感应钎焊温度为940℃时,磨粒表面生成物致密覆盖在表面,且所制备的CBN钎焊砂轮的磨削力和磨削比能较小。在相同磨削用量下,对电镀CBN砂轮和感应钎焊CBN砂轮的磨损形式进行对比分析发现,电镀CBN砂轮的磨损形式为黏附磨损,钎焊CBN砂轮的磨损形式为破碎磨损。     

磨料粒度对电镀CBN砂轮磨损影响的有限元仿真分析

以单颗CBN磨粒的磨损为例,对电镀CBN砂轮的磨损进行研究。针对磨削淬硬轴承钢GCr15,将单颗CBN磨粒适当简化成圆锥体,建立楔形滑擦模型,利用Deform 3D软件对单颗CBN磨粒的磨耗磨损进行仿真分析。仿真结果表明:不同粒度磨粒的磨损形式相似,均为前端面磨成弧形月牙洼形,尖端逐渐磨成平台;相同条件下磨粒的最大磨损量随着磨料粒度号的增大而减小。同时也说明了细粒度的电镀CBN砂轮的磨损较小。研究结果对进一步研究电镀CBN砂轮制造工艺有指导意义。     

凸轮轴加工中CBN磨削技术的应用与研究

介绍和分析了凸轮轴加工中的CBN磨削加工技术与传统的磨削技术的对比,从四个方面阐述了技术要素以及加工砂轮问题的解决方法。     

A precision grinding method for screw rotors using CBN grinding wheel

Aiming at the high precision machining of screw rotors, a new grinding method for screw rotors using cubic boron nitride (CBN) grinding wheel is presented in this paper. Small electroplated CBN grinding wheel is firstly used to grind screw rotors. The mathematical model for the axial profiles of CBN grinding wheel is developed based on gear engagement theory. Taking the backlash of screw rotors and the coating thickness of CBN layer into consideration, the modification of the base body of the wheel shape is introduced into the design of the CBN grinding wheel. Wire cut electrical discharge machining low speed (WEDM-LS) was used to machine the base body of the CBN grinding wheel. The formed turning tools of the base body of CBN grinding wheel using WEDM-LS and the wheel shapes of CBN grinding wheel using the formed turning tool were performed. The CBN grinding wheels for the screw rotors were made to verify the validity and effectiveness of the presented method. The electroplated CBN grinding wheels were used to machine the screw rotors, and the machining experiments were performed. The data obtained in the experiments reach the fifth class of Chinese Standard GB10095-88.     

金属结合层包覆单列磨粒小直径CBN砂轮端面磨削过程研究

金属结合层包覆单列磨粒小直径CBN砂轮在端面磨削过程中突出高度不同的CBN磨粒相继发生后面磨损、切削刃破碎和脱落,产生了砂轮自锐效应。砂轮磨削力呈现低频起伏和高频波动变化的特征,这是由于磨削过程中CBN磨粒后面磨损钝化使磨削力增大以及随后磨钝磨粒破碎变得锐利使磨削力减小的综合作用结果。砂轮磨削过程受到CBN磨粒性能及其切削刃状态的支配,多晶强韧CBN磨粒(BORAZON550,GE产品)耐磨性改善、磨粒微细破碎保持了砂轮的锐利性,延长了单个磨粒服务时间,突出高度不同的磨粒加入磨削过程的批次效应显著,磨削力低频起伏明显,单晶CBN磨粒(BORAZON500,GE产品)破碎范围大有效降低了磨粒切削刃突出高度、新磨粒加入磨削的过程具有连续性,磨削力高频波动明显。     

Influence of Nano/Micro CBN Particle-Coated Tools on Rolling Contact Fatigue Performance of Hard-Machined AISI 1053 Steel

In this article, we study the influence of the cubic boron nitride (CBN) particle size in nano/micro CBN particle-coated tools on the fatigue performance of hard-machined AISI 1053 steel. The effect of the CBN particle size on the crack initiation life and the crack propagation life is reduced significantly with increased loading, whereas the crack propagation life is more influenced by the CBN particle size compared with the crack initiation life. The CBN particle size can influence the crack initiation life by 96 % and the crack propagation life by 130 %. As a result, it can influence the fatigue life by 370 % at the maximum Hertzian stress of 2,724 MPa. The results demonstrate that the CBN particle size influences the fatigue life and that the effect of the CBN particle size on the fatigue life can be lessened significantly if the loading is increased to a certain level that depends on the function of machined surfaces.     

新型小直径端面CBN砂轮开发及其磨削性能研究

基于电镀小直径端面CBN砂轮磨削沟槽的试验结果,为减小沟槽底面与侧面过渡圆弧半径,开发了一种新型小直径端面CBN砂轮,在试验研究其磨削性能的基础上提出了改善措施,取得了良好的磨削效果。新型端面CBN砂轮加工沟槽的过渡圆弧半径达到0.2mm以下,比电镀CBN砂轮减小60%以上。新型端面CBN砂轮磨削过程中,由于有效CBN磨粒发生的后面磨损及其破碎,使磨粒切削刃凸出高度降低,而砂轮表面所有CBN磨粒均先后依次成为有效磨粒,因此提高单个CBN磨粒的耐磨性和韧性,减小破碎,是提高新型CBN砂轮寿命的有效措施。选用多晶强韧的CBN磨粒(通用电器GE550型产品)使砂轮寿命提高到了原来的6.75倍。     

钎焊镀膜CBN外珩齿刀的工艺研究

介绍珩齿刀钎焊镀膜CBN制作工艺，概述了钎焊镀膜CBN的工艺优势，这种新型珩齿刀以其卓越的珩削性能将会逐步代替电镀CBN珩齿刀。利用激光扫描加热的钎焊方法实现了镀膜CBN与珩齿刀基体的牢固连接，既实现了钎焊材料、CBN以及基体之间的冶金结合．又保证了基体在钎焊后的精度。     

Temperature control in CBN grinding

The main advantage of CBN grinding wheels is the long wheel life owing to the hardness of the CBN abrasive. Recent research has confirmed another advantage of CBN, which is cooler grinding. The new research allows the temperature in grinding to be predicted based on experimentally validated CBN thermal properties. This work also provides for in-process prevention of thermal damage in grinding. A well-documented feature of CBN grinding is the reduced risk of thermal damage to the workpiece. This advantage can allow a marked increase in removal rate whilst maintaining surface quality of the component compared to grinding with conventional abrasives such as aluminium oxide. The reduced risk of thermal damage in CBN grinding is sometimes attributed to the lower grinding specific energies. While lower specific energies when achieved are an advantage, this explanation ignores a fundamental advantage of the CBN abrasive. The experimental investigation has shown that a major advantage of CBN grinding is that a substantially lower proportion of the total grinding energy enters the workpiece compared to grinding with alumina wheels. The results further indicate that the effective thermal conductivity of CBN grains is considerably lower than its reported theoretical value of 1300 W(mK)^–1.