ZTA陶瓷刀具连续切削淬硬T10A时的切削性能研究

研究两种自主研制的新型ZTA(Al2O3/Zr O2)陶瓷刀具切削淬硬T10A时的切削性能。刀具后刀面磨损量随切削深度和切削速度的增加而增大;刀具的主要磨损形态为后刀面磨损;主要磨损机理为后刀面磨粒磨损和部分粘结磨损。     

冷却方式对H13A硬质合金切削性能试验分析

在MAZARK车铣加工中心和高速铣床上选用切削速度150m/min和200m/min进行顺铣干/湿切削加工,采用H13A硬质合金刀具对TC4钛合金进行高速车铣和高速铣削加工试验。分别对比分析两种加工方式下冷却方式不同时的刀具磨损形态,结果表明:干切削时,无论正交车铣或高速铣削,刀具都是以粘结磨损为主;正交车铣干切削时,刀具表面有较多的切屑粘结物,易形成积屑瘤;切削液条件下,刀面粘结物相对减少,切屑粘走刀具材料,形成较多的粘结凹坑;铣削干切削时,粘结到刀面的切屑较正交车铣少,但切屑粘走刀具材料更为严重,前刀面出现较深的月牙洼,采用切削液时前刀面出现层状剥落。试验表明,当金属切除率一定时,正交车铣干切削金属切出总量最大,刀具寿命最长,湿切削加工时刀具寿命较短,切削液对刀具磨损形态和刀具寿命影响较大,可能与热交变应力和Co元素流失有关。试验结果表明,H13A刀具正交车铣钛合金干切削时切削性能较好。     

纯钒车削刀具磨损表面形态及机理研究

对金刚石刀具、涂层刀具及硬质合金刀具车削纯钒时刀具磨损形态及其磨损机理进行观察和分析.结果表明,在所选取条件下,不同刀具材料对工件材料切削时表现出的刀具磨损形态主要为前刀面磨损、后刀面磨损、微崩刃、剥落和粘结等.刀具的前刀面主要是沿切屑流出方向的沟槽形月牙洼磨损,而后刀面以粘结磨损为主.CD10刀具和H10非涂层刀具具有较佳的切削性能,而H13A非涂层刀具和GC1025涂层刀具不适于纯钒车削.     

陶瓷刀具材料切削加工G4335V高强钢时的耐磨性能研究

本文对Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具材料切削加工Ｇ４３３５Ｖ高强钢时的切削性能和耐磨性进行了试验研究。结果表明：在低速切削条件下，Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具和硬质合金刀具（ＹＴ１５）的抗后面磨损能力相差不大，而在高速切削条件下，前者的抗后面磨损能力远高于后者。Ａｌ２Ｏ３／ＴｉＣ陶瓷刀具前面的磨损形式主要为粘结磨损，后面的磨损形式主要为磨粒磨损。     

SY钢铣削参数优化及刀具磨损机理的试验研究

通过正交切削试验,研究了用YW2和M2两种硬质合金刀具铣削SY钢新型垃圾焚烧炉炉排材料的切削性能,并获得了优化切削参数。研究结果表明:YW2硬质合金刀具更适合切削加工SY钢;YW2硬质合金铣刀的磨损机理为硬质点磨损、氧化磨损和粘结磨损。     

用于难加工材料高效切削异面涂层刀具的研制

针对切削难加工材料时刀具前后刀面磨损机理不同、刀具寿命较短的问题,提出了在刀具前后刀面分别制备不同性能涂层的新方法,并对制备的异面涂层刀具进行了切削性能试验。首先对切削难加工材料时刀具磨损机理进行了研究,结果表明,刀具前刀面易于发生粘结磨损,后刀面易于发生磨粒磨损;然后,通过多弧离子镀方法,在前刀面制备了抗粘结能力强的Al Cr N多元涂层,在后刀面上制备了抗磨粒磨损能力强的Ti CN涂层。最后,对制备好的刀具进行了切削性能测试,结果表明,异面涂层能显著提高刀具的综合力学性能。     

高速车削300M高强度钢涂层刀具失效机理研究

选用不同涂层刀具进行高速切削300M钢试验,利用工具显微镜和电子扫描显微镜(SEM)观察刀具磨损形貌,并利用线扫描进行元素扩散分析,揭示刀具失效机理。研究结果表明:金属陶瓷基涂层刀具高速切削时,切削速度不宜超过240m/min;硬质合金基涂层刀具可在300m/min以上高速切削300M钢,其中CVD-Ti CNAl2O3厚涂层的高速切削性能更高,切屑塑形变形较小;涂层刀具切削300M钢的主要磨损形式是前刀面磨损和后刀面磨损,涂层剥落、崩刃、微裂纹、粘结磨损、磨粒磨损、氧化磨损、扩散磨损是刀具失效的主要原因。     

纳米氧化锆增韧氧化铝基陶瓷刀具切削性能的研究

研究了新型陶瓷刀具A15Zc和A20Z(c+m)切削淬硬T10A时的切削性能,并与已经商业化的陶瓷刀具SG4的切削性能进行了对比。分析了两种陶瓷刀具在低速切削(99.5m/min)和高速切削(268.5m/min)时的抗磨损能力和主要磨损形态。     

钛合金零件高速铣削刀具磨损的试验研究

高速铣削钛合金时,由于切削区内的切削温度高,加剧了刀具的磨损。通过对钛合金TC4的高速铣削实验,得出带TiA lN涂层的硬质合金刀具切削钛合金TC4时的刀具磨损的变化规律和刀具耐用度公式。通过对刀具磨损特性的分析,研究结果主要是刀具表面层的粘结相Co在高温下丧失对WC颗粒的结合强度,磨损机理以高温下的粘结层撕裂磨损为主。     

硬质合金刀具铣削Ti6Al4V材料性能研究

Ti6Al4V材料具有良好的性能,广泛应用于航空、航天、医学等领域。这一材料属于典型难加工金属材料,对刀具的切削性能要求较高。对YG6硬质合金刀具干式铣削Ti6Al4V材料时的刀具磨损形态、切削力、切屑形态进行了研究,结果表明,在其它切削参数相同的条件下,低速切削时刀具磨损主要表现为粘结磨损、磨粒磨损、边界磨损。随着切削速度的加快,刀具磨损加剧,主切削刃出现微崩刃。在较高的切削速度和较大的进给量下,刀具磨损进一步加剧,刀尖处磨损最为严重,前刀面出现剥落现象。在进给量和切削深度保持不变的情况下,切削速度加快,切削力出现减小的趋势。YG6刀具切削Ti6Al4V材料容易形成节状切屑,这会对加工表面质量产生不利影响。     

硬质合金刀具铣削Ti6Al4V时刀具磨损及切削力研究

对硬质合金刀具在干切削状态下铣削Ti6Al4V磨损机理和切削力进行了试验研究,切削速度分别为40、80、120、160m／min。分析了切削力与切削方式、切削速度、切削路程的关系。最后,对刀具的磨损形态和磨损机理进行了探讨。结果表明粘结、扩散是硬质合金铣刀的主要磨损机理。     

涂层硬质合金刀具切削奥氏体不锈钢切削力的试验研究

通过四种涂层硬质合金刀具切削奥氏体不锈钢1Cr18Ni9Ti的试验,研究了切削用量对切削力的影响,并对四种刀具的切削力进行了对比分析。试验结果表明:在采用小进给量、小背吃刀量切削时,出现了背向力大于主切削力的现象;随着切削速度的增加,YBC251、GC2025刀具的切削力先减小后增大;同型号的PVD涂层硬质合金刀具与CVD涂层硬质合金刀具相比较,前者的切削力显著小于后者。     

高速干切削铁基粉末冶金零件时细晶粒硬质合金刀具的切削性能研究

用细晶粒硬质合金刀具进行了铁基粉末冶金零件的高速干切削试验。研究了切削参数与刀具耐用度以及加工表面粗糙度的关系,给出了刀具的主要磨损形态,通过能谱分析研究了刀具的磨损机理。结果表明:所选用细晶粒硬质合金刀具具有较高的刀具耐用度和较好的加工表面粗糙度,适合于铁基粉末冶金的加工;细晶粒硬质合金的主要磨损形态是前刀面的月牙洼磨损;主要磨损机理是扩散磨损、粘结磨损。     

PCBN刀具高速切削镍基高温合金切削力及刀具磨损试验研究

高速切削加工过程中切削参数的选择对刀具切削性能具有较大的影响。镍基高温合金因在高温条件下仍具有较高的抗疲劳强度、屈服强度、抗拉强度等特点,被广泛应用于航空航天、船舶、核电等行业。但是镍基高温合金的切削加工性能差,主要表现在切削力大、切削温度高、刀具磨损现象严重等方面。本文从切削速度、进给量、切削深度等切削参数对切削力的影响进行研究,同时对PCBN刀具磨损形貌进行分析。采用PCBN刀具进行高温合金车削试验,得到PCBN刀具切削高温合金GH4169时切削参数对切削力的影响规律,并探讨不同刀具磨损形貌产生的原因,为高温合金高速切削加工参数制定及工艺优化提供一定参考。     

Use of Ceramic Tools in Hard Turning of Hardened AISI M2 Steel

Tool wear and machining performance of hardened AISI M2 steel in hard turning has been studied. Ceramic tools were used in the cutting tests without coolants, and the workpiece was heat treated to increase its hardness up to Re 60. Cutting forces, temperature, and tool wear were measured in the experiments and the effects of cutting conditions on these were investigated. Important aspects from the research are summarized as follows: 1. Flank wear was the dominant wear mode on the ceramic tool insert in hard turning. In contrast, crater wear was very small due to the ceramics high resistance against chemical reactions at high temperature. A notch was unlikely to be formed in the tool.

2. The initial flank wear rate mainly depends on the feed rate. High feed rates cause a high initial flank wear rate.

3. Depth of cut was the most important cutting parameter to affect cutting force variation, and the cutting force increased due to tool wear.

     

Wear and Tool Life of CBN Cutting Tools

The wide application of precise high-quality components made of advanced structural materials is directly related to the accelerating use of superhard materials and tools made of them. When machining with these tools, the optimal choice of cutting process parameters is important, as the requirements concerning the parts can often only be satisfied by cutting under extreme conditions (small chip cross-section, high cutting speed, special materials, new wear forms, etc.). Polycrystalline CBN tools are widely used for the fine turning of parts made of construction, stainless, heat-resistant, acid-resistant or even hardened (60–70 HRC) HS steels. The experimental T = T(vc) tool life curves are of "dromedary" type. The tool life maximum point moves up and down according to changes of depth of cut and feed-rate values. The reasons for polyextreme tool life curves and moving maximum tool-life points are discussed in the paper. A new general tool life Eq. is outlined which reflects the physical principles of cutting phenomena more completely and exactly. The suggested form describes the polyextreme structure of the tool life function, while the position of the extreme values (along the T- and vc-axis) depend on the cutting parameters. ID="A1" Correspondence and offprint requests to: Professor A. G. Mamalis, Manufacturing Technology Division, Department of Mechanical Engineering, National Technical University of Athens, 42 28th October Avenue, 106 82 Athens, Greece. E-mail: mamalis@central.ntua.gr     

基于切削参数和刀具状态的车削功率模型

动态切削功率建模是切削功率信号用于切削过程监控的关键。本文首次建立了基于切削参数 (主轴转速、进给量、切削深度 (即背吃刀量 )、工件材料及刀具材料 )与刀具状态 (主要考虑后刀面磨损量 )的车削功率模型。试验证明 ,该模型基本能正确反映车削功率信号与刀具状态及各种切削参数之间的关系     

车铣加工切削机理分析

车铣加工通过将车刀更换为铣刀,增加铣刀转动自由度,基于工件转动和铣刀转动的合成运动,完成对工件的加工.车铣加工具有断屑更容易、切削温度低、切削力小等优点,即使工件低速旋转,也能实现高速切削.对车铣加工的切削机理进行了分析,具体包括刀具磨损机理、切屑形成机理、工件表面质量、难加工材料切削等.     

刀具涂层技术及涂层刀具切削性能的试验研究

在阐述刀具硬质涂层技术发展新动向的基础上,通过车削、铣削及攻丝的切削试验证明:涂层刀具的切削力总比未涂层刀具的小,且不同涂层刀具的切削力减小程度不同,在试验的几种涂层刀具中,AlTiN涂层、TiCN-WS2涂层刀具的切削力减小得多些.     

Tool Wear in Ultra-Precision Diamond Cutting of Non-Ferrous Metals with a Round-Nose Tool

Tool wear causes the loss of the original profile accuracy of the cutting edge and degrades the form accuracy of machined surfaces. The purpose of this research is to clarify the tool-wear mechanism and its effect on machining accuracy in ultra-precision diamond cutting with a round-nose tool. Controlled cutting tests of Al 6061 were performed on a two-axis, ultra-precision turning machine. Single-crystal diamond tools were used in the experiment. The tool-wear pattern was studied based on the observation of the wear zone using a scanning electron microscope. The topographic characteristics of the chips were examined and the effect of the micro-cutting geometry on the tool wear was investigated theoretically and experimentally. The mutual effects of crystallographic dependence of wear resistance of diamonds and the change in the cutting velocity during machining are believed to be the main reasons causing uneven wear along the cutting edge. Measures for reducing the effect of tool wear are also discussed.