超声振动磨削放电复合加工SiCp／Al试验研究

针对SiCp／Al的加工,提出一种超声振动磨削放电复合加工的方法．从加工效率、加工稳定性及表面质量等方面与电火花加工进行了对比试验研究。分析了两种加工方法的脉冲宽度和峰值电流对加工速度和表面粗糙度的影响,结果表明：电火花加工的表面粗糙度平均值为尺04．5μm,超声振动磨削放电复合加工的表面粗糙度平均值为Ra2μm：超声振动磨削放电复合加工的稳定性比电火花加工好,但加工速度较低。通过扫描电镜对两种加工方法下零件表面形貌和重熔层进行了观测,对试件表面进行了X射线衍射分析,表明采用超声振动磨削放电复合加工SiCp／Al复合材料可获得较好的表面质量。     

电解电火花复合加工深孔试验研究

概述了难加工材料零件打孔的几种主要工艺方法,提出此类材料小孔、深小孔加工的一种新电解电火花复合加工试验方法.在改造的试验装置上,采用复合型电解液在不锈钢、钛合金试件上进行了小孔、深小孔加工试验.分析了生产率、表面粗糙度和加工精度等工艺效果的成因.结果表明,通过合理进行电解液配制和选择电规准等相关工艺参数,试件的材料去除率达14 mm/min,表面粗糙度值Ra ＜7.9 μm.虽然加工精度低于电火花加工精度,仍验证了该方法用于钛合金试件打孔的有效性.     

时间控制法应用于某航空精密型面零件的电火花加工试验研究

时间控制法电火花加工是一种新的电火花加工工艺.介绍时间控制法的原理,并研究其应用于精密型面浅"U"型槽的电火花加工工艺.重点分析运用时间控制方案来控制零件所需的高尺寸精度,同时分析了影响零件尺寸精度和表面粗糙度的因素.通过实验表明,采用时间控制法,选择合适电规准参数,注意加工过程中的要点因素,可加工出高尺寸精度和低表面粗糙度值的精密型面,为此类高精密零件的加工提供了一种有效的加工方法.     

基于信噪比和灰关联度的TC4超声混粉电火花研究

由于TC4钛合金是一种难加工材料,采用传统机械方法难以加工,采用超声混粉电火花对其进行工艺优化研究。在正交实验基础上,利用信噪比和灰关联度两种分析方法,对超声混粉电火花加工中,脉冲宽度、脉冲间隔、间隙电压、峰值电流和超声振幅对表面粗糙度、加工时间和侧面间隙的影响进行分析,从而得到最优参数组。验证实验结果表明,使用信噪比和灰关联度相结合的优化方法对于解决多目标优化问题具有积极意义,使电火花加工TC4钛合金的加工时间减小9.87%,表面粗糙度减小11.66%,侧面间隙减小7.05%。     

精密电火花加工钛合金的参数研究

针对航空航天用难加工材料钛合金进行了精密电火花加工研究,分析了脉宽、脉间、峰值电流对表面粗糙度的影响规律,利用二元回归的方法推导了精密电火花加工的表面粗糙度经验公式,为钛合金加工的理论研究和实际应用提供了依据.     

复合电极-混粉电火花加工Ti-6Al-4V钛合金的研究

目的采用混粉电火花加工技术,使用超声电沉积制备的Cu-Si C复合电极加工TC4钛合金,在工作液中混入碳粉进行表面改性,以获取性能优异的加工表面。方法利用Cu-Si C复合电极和Cu电极对TC4钛合金进行成型加工。用扫描电子显微镜(SEM)观察加工后工件的表面形貌和熔凝层断面形貌,并用TR200粗糙度仪测量其表面不同位置的粗糙度值。用硬度仪测量工件熔凝层的显微硬度,用X射线衍射仪对材料强化层进行物相分析。并对电极损耗进行对比分析。结果 Cu电极加工的TC4钛合金表面凹坑深且面积大,熔凝层疏松,粘合性较差。Cu-Si C复合电极加工的TC4钛合金表面放电痕迹大,深度统一,电蚀产物少,熔凝层致密好。利用X射线衍射仪、硬度测量仪和粗糙度仪对试样测量分析显示,Cu-Si C复合电极加工后,表面生成的Ti C峰相高,耐磨性好,表层显微硬度较大,约为基体的6倍,表面平均粗糙度值Ra=2.825μm。复合电极损耗比铜电极损耗降低了18%。结论两种电极加工后,TC4钛合金表面均得到改善,且使用超声电沉积Cu-Si C复合电极加工后的表面质量更好。     

工件超声振动对TC4钛合金快走丝电火花线切割加工表面质量影响的研究

进行了4组对比试验,研究了工件超声振动对TC4钛合金快走丝电火花线切割加工的表面粗糙度及其表面形貌的影响。结果表明:与TC4钛合金快走丝电火花线切割加工相比,在工件上附加超声振动以后,TC4钛合金工件表面粗糙度得到降低,但改变幅度都不一样。在电参数为功率管数2个,脉冲宽度16μs,脉冲间隔比为6时,表面粗糙度改变幅度最大。对比无超声振动,发现在工件上附加超声振动以后,形成的小凹坑更加均匀规则,且小凹坑的边缘更加光滑。     

超声辅助线切割加工超声参数对表面粗糙度的影响

为提高超声振动与电火花线切割复合加工难切削金属的加工质量,通过理论分析、数值模拟和试验验证,对超声振动与电火花线切割复合加工作用下不同振幅和频率对表面粗糙度的影响规律进行深入研究。基于超声振动的电火花线切割复合加工构建物理模型和数学模型,推导基于超声振动的移动高斯热源热流密度公式,建立了完整的温度场仿真模型。通过ANSYS有限元复合加工过程温度场的模拟分析,构建基于温度场数值模拟的表面粗糙度理论计算模型。通过单因素试验对表面粗糙度的理论计算模型进行了验证,结果表明：随着振幅和频率的增大,被蚀除电蚀坑体积减小,表面质量变高;试验结果与理论及仿真模型的变化规律具有较好的一致性,最小偏差7.717%,最大偏差16.708%。     

电火花诱导烧蚀磨削修整复合加工方法研究

针对放电诱导烧蚀加工在高效加工的同时易在工件表面产生巨大烧蚀坑的问题,提出了电火花诱导烧蚀磨削修整复合加工方法。对钛合金TC4进行了电火花加工、烧蚀加工、诱导烧蚀磨削修整复合加工的对比实验,研究机械磨削作用对烧蚀性能的影响。在钛合金烧蚀加工实验过程中,用复合机械磨头进行修整能显著提高加工效率,达到1107 mm3/min,是同等条件下电火花加工的6.77倍、烧蚀加工的1.27倍。由于存在机械磨削修整作用,可在线去除烧蚀产物,露出基体材料,工件表面粗糙度优于烧蚀加工,甚至优于同等电参数下的电火花加工,达到了在获得高效加工的同时提升表面质量的目的。     

混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响

研究混粉超声振动对电火花加工Ti-6Al-4V表面结构及力学特性的影响,对传统电火花加工、混粉电火花加工及混粉超声振动电火花加工后Ti-6Al-4V试件的表面粗糙度、表面残余应力和显微硬度进行了测量,采用SEM对3种加工方法的加工试件表面重熔层及微裂纹进行了观察,采用能谱分析仪对加工表面进行了能谱分析,探讨了Al粉、SiC磨料超声振动对电火花加工表面结构和力学性能的影响机理。结果表明:在混粉电火花加工基础上,工作液中加入20 g/L的SiC颗粒,电极施加轴向超声振动,可使电火花加工表面粗糙度值Ra降低0.5μm、重熔层厚度减薄40μm、表面残余应力降低50 MPa、表面显微硬度由7650 MPa提高到9870 MPa。     

硬质合金的超声电火花复合加工速度研究

通过采用电火花加工和超声电火花复合加工的方法加工硬质合金的试验,分析超声电火花复合加工应用的限制因素,研究脉冲宽度、峰值电流等参数对加工速度的影响。结果表明,在一定的条件下超声电火花复合加工比普通电火花加工效率高、表面质量好,可用于硬质合金模具的加工。     

混粉电火花加工技术在粗加工中的应用研究

在对混粉电火花加工机理进行系统研究的基础上，对混粉电火花粗加工中的加工效率和加工表面粗糙度进行了实验研究。结果表明，通过合理选择放电参数，混粉电火花加工在相近加工表面粗糙度时，能显著提高加工效率，从而为混粉电火花加工技术在粗加工中应用提供依据。     

Surface modifications of Al–Zn–Mg alloy using combined EDM with ultrasonic machining and addition of TiC particles into the dielectric

This study proposes a novel combined process that integrates electrical discharge machining (EDM) and ultrasonic machining (USM) to investigate the machining performance and surface modification on Al–Zn–Mg alloy. In the experiment, TiC particles were added into the dielectric to explore the influence of the combined process on the material removal rate (MRR), the relative electrode wear ratio (REWR), the surface roughness and the expansion of the machined hole. The elemental distributions of titanium and carbon on the cross-section were quantitatively determined using an electron probe micro-analyzer (EPMA). Microhardness and wear resistance tests were conducted to evaluate the modifications on the machined surface caused by the combined process. The experimental results show that the combined process was associated with improved machining performance. The combination of EDM with USM yielded an alloyed layer that improved the hardness and wear resistance of the machined surface.     

Machining performance on hybrid process of abrasive jet machining and electrical discharge machining

To develop a hybrid process of abrasive jet machining (AJM) and electrical discharge machining (EDM),the effects of the hybrid process parameters on machining performance were comprehensively investigated to confirm the benefits of this hybrid process.The appropriate abrasives delivered by high speed gas media were incorporated with an EDM in gas system to construct the hybrid process of AJM and EDM,and then the high speed abrasives could impinge on the machined surface to remove the recast layer caused by EDM process to increase the efficiency of material removal and reduce the surface roughness.In this study,the benefits of the hybrid process were determined as the machining performance of hybrid process was compared with that of the EDM in gas system.The main process parameters were varied to explore their effects on material removal rate,surface roughness and surface integrities.The experimental results show that the hybrid process of AJM and EDM can enhance the machining efficiency and improve the surface quality.Consequently,the developed hybrid process can fit the requirements of modern manufacturing applications.     

Surface modification of Al–Zn–Mg alloy by combined electrical discharge machining with ball burnish machining

The study investigated the feasibility of modifying the surface of Al–Zn–Mg alloy by a combined process of electric discharge machining (EDM) with ball burnish machining (BBM). A novel process that integrates EDM and BBM is also developed to conduct experiments on an electric discharge machine. Machining parameters of the combined process, including machining polarity, peak current, power supply voltage, and the protruding of ZrO₂, are chosen to determine their effects on material removal rate, surface roughness and the improvement ratio of surface roughness. In addition, the extent to which the combined process affects surface modification is also evaluated by microhardness and corrosion resistance tests. Experimental results indicate that the combined process of EDM with BBM can effectively improve the surface roughness to obtain a fine-finishing and flat surface. The micropores and cracks caused from EDM are eliminated during the process as well. Furthermore, such a process can reinforce and increase the corrosion resistance of the machined surface after machining.     

超声磨料混粉电火花复合加工的研究

阐述了超声磨料混粉电火花复合加工基本原理和基本设备，在试验研究的基础上对加工参数进行详细的讨论，分析了主要参数对表面粗糙度的影响。     

Machining characteristics of magnetic force-assisted EDM

The gap conditions of electrical discharge machining (EDM) would significantly affect the stability of machining progress. Thus, the machining performance would be improved by expelling debris from the machining gap fast and easily. In this investigation, magnetic force was added to a conventional EDM machine to form a novel process of magnetic force-assisted EDM. The beneficial effects of this process were evaluated. The main machining parameters such as peak current and pulse duration were chosen to determine the effects on the machining characteristics in terms of material removal rate (MRR), electrode wear rate (EWR), and surface roughness. The surface integrity was also explored by a scanning electron microscope (SEM) to evaluate the effects of the magnetic force-assisted EDM. As the experimental results suggested that the magnetic force-assisted EDM facilitated the process stability. Moreover, a pertinent EDM process with high efficiency and high quality of machined surface could be accomplished to satisfy modern industrial applications.     

A comparative study of surface integrity of Ti–6Al–4V alloy machined by EDM and AECG

The electrical discharge machining (EDM) process produces the recast layer with or without cracks on the surface that requires a remedial post-treatment in the manufacture of critical or highly stressed surfaces. One of the frequently used post-treatment processes is also the abrasive electrochemical grinding (AECG) and it has been widely used in the precision machining of difficult-to-cut materials due to an enhanced surface integrity and productivity. The aim of this study is to investigate improvability of surface integrity in terms of machining voltage, electrolyte flow rate and table feed rate parameters of AECG in EDMed Ti6Al4V alloy. Scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrograph (EDS) and surface roughness measurement were performed to study the surface characteristics of the machined samples. Experimental results indicate that the AECG process effectively improves the surface roughness and eliminates the EDM damages completely by setting suitable grinding parameters.     

电火花线切割加工铜钨合金切缝宽度及加工精度影响因素研究

铜钨合金是一种广泛应用于精密及难加工材料电火花成形加工的低损耗电极材料。在窄缝、清棱清角、高纵横比等结构的电极加工中,低速走丝电火花线切割加工较传统加工方法具有一定的优势。通过单因素实验研究了电火花线切割加工参数对铜钨合金粗加工切缝宽度、加工速度及表面粗糙度的影响规律,为实际加工提供理论指导。