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1.
Junzhan Hou Wei Zhou Hongjian Duan Guang Yang Hongwei Xu Ning Zhao 《The International Journal of Advanced Manufacturing Technology》2014,70(9-12):1835-1845
Tool wear is one of the most important problems in cutting titanium alloys due to the high-cutting temperature and strong adhesion. Recently, the high-speed machining process has become a topic of great interest for titanium alloys, not only because it increases material removal rates, but also because it can positively influence the properties of finished workpiece. However, the process may result in the increase of cutting force and cutting temperature which will accelerate tool wear. In this paper, end milling experiments of Ti-6Al-4V alloy were conducted at high speeds using both uncoated and coated carbide tools. The obtained results show that the cutting force increases significantly at higher cutting speed whether the cutter is uncoated carbide or TiN/TiAlN physical vapor deposition (PVD)-coated carbide. For uncoated carbide tools, the mean flank temperature is almost constant at higher cutting speed, and no obvious abrasion wear or fatigue can be observed. However, for TiN/TiAlN PVD-coated carbide tools, the mean flank temperature always increases as the increase of cutting speed, and serious abrasion wear can be observed. In conclusion, the cutting performance of uncoated inserts is relatively better than TiN/TiAlN PVD-coated inserts at a higher cutting speed. 相似文献
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Titanium alloys are difficult-to-machine materials because of their poor machinability characteristics. Machining and machining performance evaluation for such materials is still a challenge. Individual machining performance indices like cutting forces, cutting energy and tool wear lead to ambiguous understanding. In this work, a Cumulative Performance Index (CPI) is defined which amalgamates non-dimensional forms of specific cutting energy, back force and average principal flank wear in turning. The CPI focuses upon simultaneous minimization of specific cutting energy, dimensional deviation and average principal flank wear. The defined index is then used to evaluate performance of five commercially available physical vapor deposited (PVD) TiAlN coated tungsten carbide/cobalt inserts vis-à-vis uncoated tungsten carbide/cobalt insert in turning of Ti-6Al-4V. Cutting forces were monitored during turning and tool wear was measured after turning experiments. The results showed that the performance of coated inserts was either comparable or poor than uncoated insert; and in no case, coated inserts performed better than uncoated insert. Although commercial recommendations are in place to use PVD coated inserts for enhanced machinability of titanium alloys, the use of coated inserts is not justified keeping in view the energy spent in coating and insignificant improvement in performance. 相似文献
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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. 相似文献
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The influence of nanolayer AlTiN/TiN and multilayer nanocomposite TiAlSiN/TiSiN/TiAlN hard coatings on the wear behavior and cutting performance of carbide cutting tools was investigated in face milling of hardened AISI O2 cold work tool steel (∼58 HRC) at dry conditions. Characterization of the coatings was performed using nanoindentation, scratch test, reciprocating multi-pass wear test. The chips forming during cutting process were also analyzed. Results showed that abrasive and oxidation wear are dominant tool failures. The nanolayer AlTiN/TiN coating gives the best adhesion to the substrate, the best wear resistance in machining and thus provides the longest lifetime with carbide inserts. 相似文献
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Qiulin Niu Ming Chen Weiwei Ming Qinglong An 《The International Journal of Advanced Manufacturing Technology》2013,64(5-8):623-631
Titanium and its alloys are well known as the typical different-to-cut materials because of their low thermal conductivity, high chemical reactivity, and low modulus of elasticity. During machining of titanium alloy, advanced high-speed, high-efficiency processing technologies are adopted to improve the production efficiency and reduce the production costs. The main goal of this work is to compare the performance of physical vapor deposition (PVD)-coated (TiN/TiAlN) and chemical vapor deposition (CVD)-coated (TiN/Al2O3/TiCN) carbide inserts in face milling TC6 alloy. To this end, the present paper reviewed the main works on the application of PVD- and CVD-coated tools in machining titanium alloys and the material performance of TC6 alloy, especially the machinability in machining process. Several tool life tests and tool wear experiments were carried out on a milling center with a five-axis spindle drive. Cutting forces were measured with a Kistler dynamometer. The failure modes and chip morphology were observed. Surface roughness and tool wear evolution were determined. The wear mechanism was discussed to compare the performance of PVD and CVD-coated tools. The main conclusions of this work were that the cutting tools made with PVD coating (TiN/TiAlN) had the excellent tooling quality and the main wear mechanisms were spalling and adhesion. PVD-TiN/TiAlN insert was more suitable to milling TC6 alloy than CVD-TiN/Al2O3/TiCN insert. 相似文献
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A. Biksa G. Dosbaeva S.C. Veldhuis A. Elfizy L.S. Shuster 《Tribology International》2010,43(8):1491-1499
Machining of aerospace materials is one of the major challenges of modern manufacturing. Application of nano-multilayered AlTiN/MexN PVD coatings (where Mex is a transition metal of V-VI groups of periodic table) to cemented carbide tooling results in a significant tool life improvement under conditions of cutting hard to machine alloys such as Ni-based Inconel 718 superalloy and Ti-based TiAl6V4 alloy. Microhardness and coefficient of friction of the coatings were measured during this experiment. Investigations of the coated tool life, wear behavior, chip formation (chip type and undersurface morphology) for cutting tools with nano-multilayered PVD coating were also performed. Morphology of worn tools has been studied using SEM and EDX. This study will show that metallurgical design of the nano-multilayered coating should be tailored to its application. To achieve better tool life when machining Inconel 781, adaptive nano-multilayered AlTiN/MoN coating is recommended, whereas a AlTiN/VN coating is better suited to machining TiAl6V4 alloy. A driving force behind selecting these coatings was a noticeably lower coefficient of friction at elevated temperatures. 相似文献
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Multilayer TiN/TiCN/TiN and single-layer TiAIN PVD coated carbide tools were used to machine a nickel base, C-263, alloy at high-speed conditions in order to investigate their performance in terms of tool life, surface finish and component forces generated during machining. The test results show that the triple layer, TiN/TiCN/TiN, coated inserts gave longer tool life when machining at higher speed and depth of cut conditions while the single layer, TiA/N, coated inserts produced better surface finish. The feed forces recorded were generally higher than the cutting forces. This could perhaps be attributed to the adverse effect of burr formation and work hardening of the workpiece associated with prolonged machining. Analysis of the test results indicate that the difference in thermal properties and tribo-chemical behaviour of both the coating and substrate materials are the major factors influencing the tribo-contact at the tool-chip interface during machining. Wear mechanisms of the coating materials can also affect tool performance in terms of tool life, surface finish and component forces. 相似文献
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Wear mechanisms and tool performance of TiAlN PVD coated inserts during machining of AISI 4140 steel
《Wear》2007,262(1-2):64-69
The tribological influences of PVD-applied TiAlN coatings on the wear of cemented carbide inserts and the microstructure wear behaviors of the coated tools under dry and wet machining are investigated. The turning test was conducted with variable high cutting speeds ranging from 210 to 410 m/min. The analyses based on the experimental results lead to strong evidences that conventional coolant has a retarded effect on TiAlN coatings under high-speed machining. Micro-wear mechanisms identified in the tests through SEM micrographs include edge chipping, micro-abrasion, micro-fatigue, micro-thermal, and micro-attrition. These micro-structural variations of coatings provide structure-physical alterations as the measures for wear alert of TiAlN coated tool inserts under high speed machining of steels. 相似文献
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In this study different specimens of ductile cast iron with tensile strength ranking from 400 MPa to 675 MPa were turned with K15 carbide, TiN coated and TiAlN coated tool in order to investigate wear mechanism and performance. Cutting forces and cutting temperature were similar for both coated tools, however flank wear and BUE were the lowest on the TiAlN coated tool, for this reason the TiAlN coated tool is suitable in the machining of ductile cast iron. The proposed tool wear mechanism is based on like-intermittent cutting caused by the pass from hard matrix to the soft graphite occasioning wear by adhesion. The analysis of the flank wear on coated tools is proposed by means of the wear curves in logarithmic scale instead of the usual linear scale. In this way, the change in wear rate is easily observed. This phenomenon was related with the wear out of the coating layer. The partial loss of the coating layer on cutting edge was confirmed by the EDS mapping images and SEM photographs. 相似文献
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The coating material of a tool directly affects the efficiency and cost of machining malleable cast iron.However,the machining adaptability of various coating materials to malleable cast iron has been insufficiently researched.In this paper,turning tests were conducted on cemented carbide tools with different coatings(a thick TiN/TiAlN coating,a thin TiN/TiAlN coating,and a nanocomposite(nc)TiAlSiN coating).All coatings were applied by physical vapor deposi-tion.In a comparative study of chip morphology,cutting force,cutting temperature,specific cutting energy,tool wear,and surface roughness,this study analyzed the cutting characteristics of the tools coated with various materials,and established the relationship between the cutting parameters and machining objectives.The results showed that in malleable cast iron machining,the coating material significantly affects the cutting performance of the tool.Among the three tools,the nc-TiAlSiN-coated carbide tool achieved the minimum cutting force,the lowest cutting tempera-ture,least tool wear,longest tool life,and best surface quality.Moreover,in comparisons between cemented-carbide and compacted-graphite cast iron machined under the same conditions,the wear mechanism of the coated tools was found to depend on the cast iron being machined.Therefore,the performance requirements of a tool depend on multiple factors,and selecting an appropriately coated tool for a particular cast iron material is essential. 相似文献
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T. V. Sreerama Reddy M. Venkatarama Reddy R. Venkatram A. Senthilkumar 《Machining Science and Technology》2013,17(2):269-281
In the present work, coated tungsten carbide tool inserts of ISO P-40 grade were subjected to deep cryogenic treatment at ?176°C. Turning studies were conducted on AISI 1040 workpieces using both untreated and deep cryogenic treated tungsten carbide cutting tool inserts. The turning performance was evaluated in terms of flank wear of the cutting tool inserts, main cutting force and surface finish of the machined workpieces. The flank wear of deep cryogenic treated carbide tools was observed to be lower than that of untreated carbide tools in machining of AISI 1040 steel. The cutting force during machining of AISI 1040 steel was lower with the deep cryogenic treated carbide tools when compared with the untreated carbide tools. The surface finish produced on machined AISI 1040 steel workpieces was superior with the deep cryogenic treated carbide tools as compared to the untreated carbide tools. 相似文献
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具有高硬度、耐高温、高耐磨性能和良好韧性的涂层刀具在干式切削加工中的应用越来越多,不同涂层刀具的应用场合及先进涂层的开发已成为目前涂层刀具技术研究的重点。本文基于TiAlN、AlTiN和TiAlN+WC/C三种涂层刀具在干式铣削加工SKD11时的切削力、切削温度和刀具磨损等物理量,对其切削性能作了详细分析。研究结果表明:在干铣加工SKD11时TiAlN+WC/C涂层刀具和AlTiN涂层刀具优于TiAlN涂层刀具,其中AlTiN涂层刀具的涂层材料硬度最高,而且在切削高温影响下生成Al2O3的薄膜层能延长该涂层刀具的寿命;TiAlN+WC/C涂层刀具的切削力小、刀具耐用度高,是干式铣削加工模具钢SKD11的理想刀具。 相似文献
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采用AlTiN涂层4刃?10 mm硬质合金立铣刀,在VMC850立式加工中心上对TC4钛合金进行铣削精加工试验。利用高精密数字化检测设备,对加工成形的TC4钛合金试件表面粗糙度、平面度、平行度、表面形貌、残余应力及显微硬度测量。分析AlTiN涂层刀具在设定不同工艺参数条件下TC4钛合金的整体加工质量和表面形貌变化规律。结果表明:在主轴转速n=8000 r/min、每齿进给量f z=0.04 mm/z、切削深度Δd=0.5 mm的最优精铣工艺参数下,TC4钛合金工件的加工质量和表面形貌好,刀具寿命长,其平面度为0.39μm,平行度为0.33μm,表面粗糙度为0.70μm,表面残余应力为-175 MPa,表面显微硬度为269 HV 0.2,实现了TC4钛合金的高质量高效率的精铣加工。 相似文献
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A. Y. L. Yong K. H. W. Seah M. Rahman 《The International Journal of Advanced Manufacturing Technology》2007,32(7-8):638-643
This paper describes a study on the effects of cryogenic treatment of tungsten carbide. Cryogenic treatment has been acknowledged
by some as a means of extending the tool life of many cutting tool materials, but little is known about the mechanism behind
it. Thus far, the only few detailed studies conducted pertain to the cryogenic treatment of tool steels. However, tungsten
carbide cutting tools are now in common use in industry. This paper primarily reports and analyses the differences in tool
performance between cryogenically treated and untreated tungsten carbide tool inserts during the high-speed milling of medium
carbon steel. In addition to dry cutting, machining with coolant was also tested. From the results, it can be seen that cryogenically
treated tools exhibit better tool wear resistance than untreated ones. Also, it is evident that the application of coolant
during cutting helps to reduce tool wear experienced by the cryogenically treated tools even further. In addition, cryogenically
treated tools are found to perform best under a particular set of cutting conditions. 相似文献
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涂层刀具在高速干切削钛合金时容易出现刀具磨损严重、刀具寿命短等问题,对涂层刀具进行表面处理能改善涂层刀具的表面完整性,是提高涂层刀具耐磨性和切削寿命的有效途径。选取TiAlSiN涂层刀具,分别进行深冷处理、微喷砂处理和深冷+微喷砂处理,研究不同处理方法对涂层刀具表面完整性(包括表面形貌、表面粗糙度、显微硬度和表面残余应力等)的影响,并进行钛合金高速干切削试验,分析不同处理方法对涂层刀具切削性能的影响,探究提高涂层刀具耐磨性和切削寿命的方法。结果表明:与单一深冷处理和微喷砂处理相比,深冷+微喷砂处理后涂层刀具表面完整性明显改善,刀具寿命显著提高。深冷+微喷砂处理能减少刀具崩刃、月牙洼磨损和磨粒磨损,有效提高涂层刀具耐磨性。 相似文献