共查询到20条相似文献,搜索用时 46 毫秒
1.
Eun-Sang Lee Tae-Hee Shin Baek-Kyoum Kim Seung-Yub Baek 《International Journal of Precision Engineering and Manufacturing》2010,11(1):113-118
Ni-Ti, a shape memory alloy (SMA), can recover from deformation to its initial shape when heated. With using this effect,
Ni-Ti SMA is applied for several industries such as a medical industry, an aerospace, electrical application on a part of
micro structure. The Ni-Ti alloy used for SMA is composed of approximately 56% nickel and 44% titanium. With this composition,
Ni-Ti alloy cannot be machined efficiently using traditional machining tools and methods such as the lathe, milling, and drilling
because it shares the poor heat dispersion characteristics of titanium. Thus, Ti-Ni SMA should be machined using non-traditional
machining methods. Electrochemical micro machining (EMM) is one form of non-traditional machining that can be applied to Ni-Ti
SMA. As an anodic dissolution process, EMM allows the machining of complex shapes in Ti-Ni SMA without the generation of heat
and without causing tool wear during the machining process. In this study, through the experiment that making the micro-groove,
the characteristic of short pulse electrochemical machining (SPECM) process is accomplished to Ni-Ti SMA. And an evaluation
of various machining factors for Ni-Ti SMA is also performed, through the substitution of different types of power source
and machining time, and through simulation of the material removal rate (MRR). The experimental and simulation results are
analyzed and compared. 相似文献
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Nickel alloys possess the excellent potential at high temperature and resistance to oxidation/corrosion owing to its high nickel content. These materials necessitate non-traditional machining methods. The rotary ultrasonic machining (RUM) process comes into existence as a superior alternative to the conventional machining of nickel alloys. The processing of these alloys using RUM needs attention. This article details the multi-response optimization in RUM of nickel alloy using the desirability concept. The present work is carried out with two shapes of the tool: (i) Plain tool and (ii) lateral slotted tool. During RUM, the process parameters—power rating tool rotation, abrasive diamond grit size and feed rate are varied. Compared with the plain tool, the lateral slotted tool shows the more efficient machining rate (MR) with less tool wear (TW). The micro-graphs disclose the mechanism of MR and TW during RUM. 相似文献
4.
Shirish D. Dhobe B. Doloi B. Bhattacharyya 《The International Journal of Advanced Manufacturing Technology》2011,55(1-4):177-188
Electrochemical machining (ECM) process has great potential on account of the versatility of its applications. ECM is being widely used in the manufacturing industry because hard metals can be machined regardless of the mechanical property of a work piece. Titanium is broadly used in a number of fields such as aerospace, power generation, automotive, chemical including petrochemical, and sporting goods. Apart from these applications, it has tremendous prospective in dental, medical industries, and biomedical engineering. The biological performance of titanium implant depends on their surface topography and form accuracy that includes various surface parameters. ECM is one of the alternative machining processes that can be applied to the machining of titanium implant for biomedical applications. The aim of this paper is to present experimental result of surface characteristics obtained on titanium samples, utilizing developed cross-flow electrolyte supply system in electrochemical machining. It is observed that electrolyte flow velocity and voltage between electrodes are some of the influencing parameters, which affect the surface characteristics. Titanium oxide layer has been generated on the machined surface, which facilitates the improvement of the corrosion and chemical resistance of titanium implant. Effects of electrolyte flow velocity and voltage during electrochemical machining process for generation of various surface characteristics have been successfully studied through experimentation. In the present work, the obtained surface roughness values on the titanium sample machined by ECM were in the range of 2.4 to 2.93???m, which is within acceptable value for the implants. Effects of electrolyte flow velocity and voltage on the material removal rate and machining accuracy in the form of overcut are also presented in the paper. 相似文献
5.
Simultaneous optimisation of multiple performance characteristics in micro-EDM drilling of titanium alloy 总被引:1,自引:1,他引:0
M. S. Azad A. B. Puri 《The International Journal of Advanced Manufacturing Technology》2012,61(9-12):1231-1239
Micro-electrical discharge machining (micro-EDM) has become a widely accepted non-traditional material removal process for machining conductive and difficult-to-cut materials effectively and economically. Being a difficult-to-cut material, titanium alloy suffers poor machinability for most cutting processes, especially the drilling of micro-holes using traditional machining methods. Although EDM is suitable for machining titanium alloys, selection of machining parameters for higher machining rate and accuracy is a challenging task in machining micro-holes. In this study, an attempt has been made for simultaneous optimization of the process performances like, metal removal rate, tool wear rate and overcut based on Taguchi methodology. Thus, the optimal micro-EDM process parameter settings have been found out for a set of desired performances. The process parameters considered in the study were pulse-on time, frequency, voltage and current while tungsten carbide electrode was used as a tool. Verification experiments have been carried out and the results have been provided to illustrate the effectiveness of this approach. 相似文献
6.
TiNiCu alloy belongs to new class of shape memory alloy (SMA), which exhibits superior properties like shape memory effect, super elasticity and reversible martensitic transformation phase and thus find broad applications in actuators, micro tools and stents in biomedical components. Even though, SMA demonstrates outstanding property profile, traditional machining of SMAs is fairly complex and hence non-traditional machining like wire electric discharge machining (WEDM) has been performed. Hence, there is a need to investigate the WEDM performance characteristics of shape memory alloys due to excellent property profile and potential applications. In the present investigation, various machining characteristics like material removal rate (MRR), surface roughness, surface topography and metallographic changes have been studied and the influence of wire material on TiNiCu alloy machining characteristics has also been evaluated through ANOVA. Ti50Ni50−xCux=10, 20 was prepared by vacuum arc melting process. The proposed alloy as-cast material exhibits austenite property (B2 phase) and having higher hardness when compared to TiNi alloy. The investigation on WEDM of Ti50Ni50−xCux alloy reveals that the machining parameters such as servo voltage, pulse on time and pulse off time are the most significant parameters affecting MRR as well as surface roughness using both brass and zinc coated brass wires. However, machining with zinc coated brass wire yields reduced surface roughness and better MRR and also produces less surface defects on the machined surface of Ti50Ni50−xCux alloys. 相似文献
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MULTI-OBJECTIVE OPTIMIZATION OF ABRASIVE FLOW MACHINING PROCESSES USING POLYNOMIAL NEURAL NETWORKS AND GENETIC ALGORITHMS 总被引:1,自引:0,他引:1
M. Ali-Tavoli N. Nariman-Zadeh A. Khakhali M. Mehran 《Machining Science and Technology》2006,10(4):491-510
Abrasive flow machining (AFM) is an economic and effective non-traditional machining technique, which is capable of providing excellent surface finish on difficult to approach regions on a wide range of components. With this method, it has become possible to substitute various time-consuming deburring and polishing operations that had often lead to non-reproducible results. In this paper, group method of data handling (GMDH)-type neural networks and Genetic algorithms (GAs) are first used for modelling of the effects of number of cycles and abrasive concentration on both material removal and surface finish, using some experimentally obtained training and testing data for brass and aluminum. Using such polynomial neural network models obtained, multi-objective GAs (non-dominated sorting genetic algorithm, NSGA-II) with a new diversity preserving mechanism are then used for Pareto-based optimization of AFM considering two conflicting objectives such as material removal and surface finish. It is shown that some interesting and important relationships as useful optimal design principles involved in the performance of AFM can be discovered by the Pareto-based multi-objective optimization of the obtained polynomial models. Such important optimal principles would not have been obtained without the use of both GMDH-type neural network modelling and multi-objective Pareto optimization approach. 相似文献
10.
Abrasive flow machining (AFM) is an economic and effective non-traditional machining technique, which is capable of providing excellent surface finish on difficult to approach regions on a wide range of components. With this method, it has become possible to substitute various time-consuming deburring and polishing operations that had often lead to non-reproducible results. In this paper, group method of data handling (GMDH)-type neural networks and Genetic algorithms (GAs) are first used for modelling of the effects of number of cycles and abrasive concentration on both material removal and surface finish, using some experimentally obtained training and testing data for brass and aluminum. Using such polynomial neural network models obtained, multi-objective GAs (non-dominated sorting genetic algorithm, NSGA-II) with a new diversity preserving mechanism are then used for Pareto-based optimization of AFM considering two conflicting objectives such as material removal and surface finish. It is shown that some interesting and important relationships as useful optimal design principles involved in the performance of AFM can be discovered by the Pareto-based multi-objective optimization of the obtained polynomial models. Such important optimal principles would not have been obtained without the use of both GMDH-type neural network modelling and multi-objective Pareto optimization approach. 相似文献
11.
张宏友 《机械工程与自动化》2012,(4):111-112
在总结目前滚动轴承加工制造的终加工工序及光整加工概念的基础上,主要论述了滚动轴承的振动抛光方法及加工机理,以及滚动轴承自修磨技术(ART)的加工机理及应用特点,并进一步提出了光整加工新技术、新工艺,如电化学加工、磁流变抛光、超声波磁流变复合抛光、电泳抛光、磨料流抛光等在滚动轴承加工制造中的应用,以期改变传统滚动轴承的抛光要求,在提高表面光洁度的基础上,进一步提高滚动轴承的几何精度和力学性能。 相似文献
12.
An integrated framework of statistical process control and design of experiments for optimizing wire electrochemical turning process 总被引:2,自引:1,他引:1
Salah Haridy Sherif Araby Gouda Zhang Wu 《The International Journal of Advanced Manufacturing Technology》2011,53(1-4):191-207
Design of experiments (DOE) and statistical process control (SPC) have been separately used in many traditional and non-traditional machining processes, but recently these two approaches are being combined and reevaluated for more effective use and accurate conclusions. DOE and SPC are very efficient tools to maintain the process on target and within boundaries of natural variations and to achieve the maximum accuracy and effectiveness of an experimental program. This paper proposes an integrated framework of SPC and DOE to execute the experimental procedures and to investigate a reliable mathematical model for optimizing the wire electrochemical turning process (WECT). WECT is a non-traditional machining process which has tremendous applications in modern industries especially in the aerospace and military industries. Response surface methodology is used to determine the sufficient number of experiments and also the recommended values of the input parameters. Univariate and multivariate control charts are used to assess the statistical control of the output parameters. Multi-objective optimization is conducted for determining the optimum values of the input parameters. 相似文献
13.
以镍粉和钛粉为原料,采用自蔓延燃烧合成技术制备了多孔NiTi形状记忆合金,研究了压坯压力、镍含量、钛粉粒径等参数对合金孔隙尺寸、孔隙均匀性和显微组织的影响。结果表明:自蔓延燃烧合成的NiTi合金为螺旋分层结构;压坯压力在100~200 MPa范围内再经自蔓延燃烧合成的NiTi合金的孔隙均匀,且为三维连通结构,比较理想;镍质量分数为40%左右时,孔隙的分布和三维贯通性均较理想;当钛粉粒径较大时,出现了大量的液相和NiTi2、Ni3Ti等杂质相,反应很不充分,钛粉粒径在50~100μm之间为好。 相似文献
14.
This article correlates laboratory-based understanding in machining of titanium alloys with the industry based outputs and finds possible solutions to improve machining efficiency of titanium alloy Ti-6Al-4V. The machining outputs are explained based on different aspects of chip formation mechanism and practical issues faced by industries during titanium machining. This study also analyzed and linked the methods that effectively improve the machinability of titanium alloys. It is found that the deformation mechanism during machining of titanium alloys is complex and causes basic challenges, such as sawtooth chips, high temperature, high stress on cutting tool, high tool wear and undercut parts. These challenges are correlated and affected by each other. Sawtooth chips cause variation in cutting forces which results in high cyclic stress on cutting tools. On the other hand, low thermal conductivity of titanium alloy causes high temperature. These cause a favorable environment for high tool wear. Thus, improvements in machining titanium alloy depend mainly on overcoming the complexities associated with the inherent properties of this alloy. Vibration analysis kit, high pressure coolant, cryogenic cooling, thermally enhanced machining, hybrid machining and, use of high conductive cutting tool and tool holders improve the machinability of titanium alloy. 相似文献
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The concept of electrochemical discharge machining (ECDM), also known as electrochemical spark machining (ECSM), was presented for the first time in 1968. Since then, this technology remains as research topic and was never explained seriously for industrial applications. The ECDM is a non-traditional machining technology used for machining of electrically non-conducting materials like glass, ceramics, quartz, etc. The literature reveals that the concept of mechanism of material removal in this machining process is not yet understood well. However, phenomena involved in the material removal needs to be investigated well in order to improve the process. In this paper, the concept of mechanism of material removal in ECDM is reviewed till date; scopes for further research have been identified. Possible future efforts to enhance the material removal rate in ECDM are also discussed. 相似文献
16.
J. Wilks 《Precision Engineering》1980,2(2):57-72
Mechanical behaviour and properties of diamonds are more complex than is generally recognised. They have a significant influence on the performance of single crystal diamonds used in precision machining operations. This article relates such factors as crystallographic orientation, polishing methods, surface interactions between tool and workpiece, fracture, chipping, and fatigue to the use of diamond tooling 相似文献
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Guilherme Ferreira Gomes Fabricio Alves de Almeida Sebastiao Simões da CunhaJr Antonio Carlos AncelottiJr 《The International Journal of Advanced Manufacturing Technology》2018,98(5-8):1155-1162
Due to the superior properties of titanium alloys, there are more and more applications of the ultra-precision situations. Nevertheless, the machinability of titanium alloys in the ultra-precision machining is still very poor. To investigate the effect of ultra-precision polishing path on the surface quality of titanium alloy Ti6Al4V, a series of ultra-precision polishing tests of titanium alloy have been carried out after the ultra-precision turning tests. The results proved that the better surface quality can be obtained using the zigzag path in the ultra-precision polishing of titanium alloys. In addition, the finite element model (FEM) has been presented to simulate the press distribution and elastic deformation of the polished surface. The results of simulation proved that the zigzag path can increase the press and deformation on the workpiece. 相似文献
19.
Jeong Woo Park Deug Woo Lee 《The International Journal of Advanced Manufacturing Technology》2009,40(7-8):742-748
Electrochemical polishing using a pulsing current is a potential alternative process for polishing micro patterns or microrecesses generated by pulse electrochemical machining. Pulse electrochemical polishing processes are attractive compared to conventional electrochemical polishing processes based on a continuous current because they allow instantaneous electrochemical reaction by applying ultrashort voltage pulses. However, there have been few attempts for calculating preferable pulse durations of the electrochemical process. To predict the preferable pulse durations, the specific polarization resistance and time constant should be obtained from a charging/discharging analysis of electrical double layer. This study describes a means of controlling physical and electrical conditions to achieve polished micro pattern or microrecess with lustrous and smooth surfaces while maintaining their original micro-scale shapes. 相似文献
20.
A. Pramanik 《The International Journal of Advanced Manufacturing Technology》2014,70(5-8):919-928
Titanium alloys are known as difficult-to-machine materials. The problems of machining titanium are many folds which depend on types of titanium alloys. This paper investigates the underlying mechanisms of basic challenges, such as variation of chip thickness, high heat stress, high pressure loads, springback, and residual stress based on the available literature. These are responsible for higher tool wear and worse machined surface integrity. In addition, many cutting tool materials are inapt for machining titanium alloys as those materials are chemically reactive to titanium alloys under machining conditions. To address these problems, latest techniques such as application of high pressure coolant, cryogenic cooling, tap testing, thermally enhanced machining, hybrid machining, and use of high conductive cutting tool and tool holder have also been discussed and correlated. It seems that all the solutions are not yet well accepted in the industrial domain; further advancement in those fields are required to reduce the machining cost of titanium alloys. 相似文献