铣削条件对高速铣削淬硬钢TiAlN涂层刀具磨损的影响

针对硬度分别为50 HRC和60 HRC的Cr12MoV淬硬钢材料,采用TiAlN涂层刀具进行了高速铣削试验,重点研究了铣削方式、刀具螺旋角以及润滑方式等铣削条件对刀具磨损的影响.结果表明:高速铣削淬硬钢时,导致刀具失效的典型形式是后刀面磨损;铣削方式、刀具螺旋角以及润滑方式对刀具磨损的影响是不同的;材料硬度50 HRC时,刀具螺旋角是刀具磨损的主要影响因素;材料硬度60 HRC时,润滑方式是刀具磨损的主要影响因素.     

淬硬钢高速铣削试验研究

针对淬硬钢选择了Cr12MoV进行了高速铣削研究,重点研究了铣削力、刀具对铣削过程的影响。结果表明：铣削方式、刀具螺旋角以及润滑方式对铣削力、刀具磨损的影响是不同的;随铣削速度的增加铣削力呈明显上升趋势。高速铣削刀具后刀面磨损,伴随加工的整个过程。淬硬钢高速铣削加工既可以保证加工表面的质量,又可以获得较高的生产效率。     

涂层刀具高速铣削高硬度淬硬钢的振动研究

高硬度淬硬钢高速铣削过程具有高铣削速度和高加工表面硬度的特性,平稳高效的铣削能保证加工质量和精度,铣削振动的产生限制了硬态切削技术优越性的发挥.通过设计在不同加工工艺参数条件下涂层刀具高速铣削高硬度(HRC 48～68)淬硬钢试验,使用LMS Test9A测试分析软件采集铣削振动信号,进行时域和频域分析,研究铣削振动与...     

淬硬钢高速铣削用量确定方法的研究

采用高速铣削技术加工淬硬钢可以大大改善材料去除率和表面粗糙度,并提高淬硬钢加工效率,降低加工成本.为获得必要的加工精度、表面质量及延长刀具寿命,铣削淬硬钢材料除精心选择刀具材料和几何参数外,必须优化铣削用量.基于淬硬钢高速铣削参数对铣削力影响的理论分析,得出高速铣削淬硬钢宜采用高转速、低进给、小切深的方式进行铣削加工的结论.比较分析了确定淬硬钢高速铣削用量的常用3种方法.     

淬硬钢高速铣削参数优化试验研究

采用正交试验法对切削力和粗糙度两个试验指标进行优化,最后采用综合平衡法确定出一组最优方案。经验证满足加工要求,达到了试验目的。     

高速铣削淬硬钢的研究进展

对国内外高速铣削淬硬钢的研究成果进行评述.讨论高速切削的概念和特点、切削力、金属软化效应、涂层刀具加工淬硬钢的切削性能、切屑形成机理、冷却方式以及对加工表面的影响,并提出高速铣削淬硬钢研究中的热点问题.     

高速铣削淬硬钢表面粗糙度的试验研究

通过切削试验研究了高速铣削淬硬钢时刀具变量中的几何参数(铣刀的前角、后角、螺旋角)、工件变量(工件硬度)和切削参数变量(铣削速度、每齿进给量)对加工表面粗糙度的影响。根据对试验结果的分析得出高速铣削淬硬钢工件表面粗糙度的变化规律。     

高速铣削淬硬钢时的切屑形态试验研究

使用Ti Al N涂层整体圆柱立铣刀,以(151~942)m/min的铣削速度,对淬硬的45钢和3Cr2Mo钢进行了高速铣削试验,研究了各种切削速度下的宏观及微观切屑形态。发现在高的铣削速度下形成了带有绝热剪切带的锯齿形切屑,并分析了切屑形态的演化过程。工件材料的硬度、强度、导热性能及切削速度对切屑形态和绝热剪切带的形成有着重要的影响。工件材料越硬、强度越高、导热系数越低,切削速度越大,越容易形成带有绝热剪切带的锯齿形切屑,而且,随着切削速度的增加,切屑的形态由卷曲向平坦发展。     

淬硬钢Cr12高速铣削力实验研究

对淬硬钢Cr12进行了高速铣削实验研究,研究了铣削速度、背吃刀量、进给速度对铣削力的影响。研究表明:铣削力随着铣削速度的增加而减小,当铣削速度增加到一定的值后其下降趋势变得平缓;铣削力随背吃刀量的增大而增大,且变化显著;铣削力随进给速度的增加而增加,但增加不大。     

高速铣削淬硬钢的表面粗糙度的试验研究

通过试验,对CBN刀具高速铣削淬硬钢工件的表面粗糙度进行了分析。表明润滑方式对表面粗糙度的影响最大,刀具螺旋角的影响次之,而铣削方式的影响较小。     

Abrasive wear behaviour of hardened high strength boron steel

Abstract

Abrasive wear in industrial applications such as mining, materials handling and agricultural machinery constitutes a large part of the total wear. Hardened high strength boron steels are known for their good wear resistance and mechanical properties, but available results in the open literature are scarce. This work aims at investigating how different quenching techniques affect the two-body abrasive wear resistance of hardened high strength boron steels. Furthermore, the wear as a function of depth in thicker hardened high strength boron steel plates has also been studied. The material characterisation has been carried out using microhardness, SEM/energy dispersive spectroscopy and three-dimensional optical surface profilometry. The results have shown that water quenched and tool quenched high strength boron steel had similar wear resistance. The main wear mechanisms appear to be microcutting combined with microfatigue. Workhardening during the abrasion process has been found to affect the abrasive wear.     

硬车代磨表面粗糙度试验研究

使用硬质合金刀具、陶瓷刀具和PCBN刀具对渗碳淬硬钢20CrMnTi进行干式车削试验,通过测量不同切削条件下的表面粗糙度值,得出切削速度、进给量对表面粗糙度的影响规律,验证了以车代磨的干式切削渗碳淬硬钢20CrMnTi的可行性.     

汽车链磨损失效机理的试验研究

通过多挂链条的道路行驶试验与台架模拟试验,研究了汽车链的磨损失效机理,微观分析了销轴、套筒和滚子等元件的磨损表面形貌,进而分析其磨损机制。试验分析表明:在汽车链传动中,链条元件存在典型的疲劳磨损和微动磨损,并伴有磨粒磨损和粘着磨损现象。针对这种磨损失效机理及其影响因素,可以有针对性地研究强化汽车链耐磨性的措施,如:合理选取链条元件的材料、采用合理的强化工艺以及合理选择汽车链传动的润滑剂和润滑方式等。     

Experimental study of the chip morphology in turning hardened AISI D2 steel

The study of local mechanisms of material removal is essential in all problems of shaping by machining. Indeed, the mastery of surfaces generated by cutting requires an understanding of cutting mechanisms. The turning of steels with high mechanical properties using the cutting tool, often called “hard turning,” is a new technique for the mechanical industry, and hence the need to understand the cutting mechanisms. The steel type EN X160CrMoV12 treated to 62 HRC (cold work tool steel: AISI D2 with a martensite matrix and distribution of primary and secondary carbides) is the subject of this study. Hard turning tests were carried out for this steel at different cutting conditions, with the aim to understand the mechanism of chip formation in order to be able to obtain the optimal cutting conditions. The chips obtained were examined under a microscope. The observation showed that the chip formation is influenced by cutting conditions. The chips contained a white layer, and this layer was examined under scanning electronic microscope (SEM) to study its variation depending on cutting parameters. The study shown, that cutting forces decrease with the increase of cutting speed. However, ANOVA method was used to establish the effect of the cutting conditions on experimental obtained results. Analysis of plastic deformation of the chip and the shear angle was made according to cutting conditions. Finally, a microhardness test was carried out to relate the mechanical properties and the microstructures of white layers.     

AISI 304不锈钢铣削加工刀具磨损实验研究

AISI 304不锈钢具有低导热性和高韧性等特性,切削加工性较差。研究采用复合涂层硬质合金铣刀,对AISI 304不锈钢进行了端铣实验研究,考察后刀面磨损情况。实验表明,进给率对磨损的影响大于切削速度。针对刀具后刀面磨损,给出了相对较好的切削条件组合。     

高速铣削硬态40CrNiMoA的试验研究

针对硬态40CrNiMoA（47HRC），在干切和空气油雾环境下，选用黛杰整体硬质合金（K30）涂层（涂层材料为TiAIN）立铣刀在Mikron UCP710高速加工中心上作了试验研究。并通过试验结果对两种铣削环境下的铣削力作了比较，得出不同铣削参数和铣削环境下高速铣削硬态40CrNiMoA（47HRC）铣削力的变化规律。     

高速铣削铁基高温合金的试验研究

针对铁基高温合金(GH696)在干切环境下,选用超细晶粒硬质合金(涂层材料为TiAlN)机夹式铣刀在Mikron UCP 710五轴联动加工中心上作了切削试验研究.获得了不同环境下,铣削力和切削参数的变化关系,分析了高速铣削铁基高温合金铣削力随着铣削参数变化的趋势和原因.     

Tool life and wear mechanism of coated and uncoated Al2O3/TiCN mixed ceramic tools in turning hardened alloy steel

The focus of this paper is the continuous turning of hardened AISI 52100 (～63HRc) using coated and uncoated ceramic Al₂O₃–TiCN mixed inserts, which are cheaper than cubic boron nitride (CBN) or polycrystalline cubic boron nitride (PCBN). The machinability of hardened steel was evaluated by measurements of tool wear, tool life, and surface finish of the workpiece. Wear mechanisms and patterns of ceramic inserts in hard turning of hardened AISI 52100 are discussed. According to the results obtained, fracture and chipping type damages occur more frequently in uncoated tools, whereas crater wear is the more common type of damage in TiN coated tools. Most important result obtained from the study is that TiN coating and crater wear affect chip flow direction. In uncoated ceramic tool, the crater formation results in decrease of chip up-curl radius. Besides, uncoated cutting tool results in an increase in the temperature at the tool chip interface. This causes a thermal bi-metallic effect between the upper and lower sides of the chip that forces the chip to curl a smaller radius. Chips accumulate in front of the tool and stick to the workpiece depending on the length of the cutting time. This causes the surface quality to deteriorate. TiN coating not only ensures that the cutting tool is tougher, but also ensures that the surface quality is maintained during cutting processes.     

Experimental research material characteristics effect on white layers formation in grinding of hardened steel

Many studies have been performed on the formation of white layer. However, little study has been done to investigate the effects of material characteristics on the formation and thickness of white layer. In this study, grinding experiments are carried out by using four different steels (hardened and annealed) as workpiece material. The specimens are analyzed using a microhardness tester and an optical microscope. The experiments indicate the depth of white layer increases with the carbon content of workpiece materials. There is a critical carbon content (about 0.77 %) associated with thick white layer. Microhardness of white layer increases with the carbon content in hardened steel. A higher hardness is observed in the hardened steel than that in annealed steel, while there is not a softer transition zone in the annealed steel. White layer varies with the different combinations of grinding parameters. White layer thickness increases with the grinding depth and wheel speed. Based on experimental data, nonlinear regression statistical models are proposed to predict white layer thickness during grinding.