球头阴极电解铣磨加工TC4钛合金试验研究

采用直径6 mm的球头阴极,通过内喷液式的供液方式,对TC4钛合金进行电解铣磨加工粗精加工试验研究.结果表明:采用球头阴极可以实现底面为曲面的沟槽加工,电解铣磨加工方法可以对沟槽进行连续的粗精加工,实现TC4钛合金曲面沟槽的高效精密加工.     

球形阴极数控电解加工的流场仿真及试验研究

针对球形阴极数控电解加工的流场设计,以电解液的流道为物理模型建立了相应的数值模型,应用计算流体力学方法对流场的数值模型进行求解,得到流场的速度和压力分布。根据求解结果,分析了阴极内部结构和出液口形状对流场的影响;通过改进阴极的内部结构和出液口形状,得到了较为理想的流场仿真结果;结合工艺试验,验证了仿真结果的准确性。     

涡轮叶片电解加工的流场仿真分析

涡轮叶片是航空发动机中的重要零件,主要加工方式是电解加工。基于电解加工流场理论,建立涡轮叶片的三维模型和电解加工的流场模型。应用COMSOL Multiphysics软件对涡轮叶片电解加工进行流场仿真分析,研究流场的分布及特性,分析不同加工间隙和不同电解液压力对流场的影响。通过分析,得出涡轮叶片电解加工时加工间隙、电解液压力与流场流速之间的关系。     

双缘板叶片电解加工流场优化与试验研究

针对在长叶身的双缘板叶片电解加工中由于流场的不均匀经常导致加工短路的问题,开展了叶片电解加工流场优化仿真分析,结果表明大量电解液从两侧缘板区域的间隙中被分流,造成叶身型面部分流量减小,导致产物不能及时排出间隙,容易引起加工短路。为了改善加工区域流场分布不均的情况,提出了一种基于液体密封的多向辅助供液流场方式,对提出的流场方式开展流场仿真分析,仿真结果表明加工区流场稳定性与一致性显著提升。开展了所提出流场的电解加工工艺试验,加工过程电流稳定,试件具有较好的加工效果,验证了提出流场方式的有效性。     

球形磨头铣磨加工钛合金的铣磨力模型与实验研究

以球形磨头上单颗磨粒的铣磨力模型为基础,结合有效磨粒数和单位铣磨力模型,建立球形磨头铣磨力数学模型,为验证铣磨力数学模型的正确性,进行球形磨头铣磨钛合金实验,分析铣磨参数对铣磨力的影响规律,进而给出铣磨参数的选取建议。结果表明：建立的磨头铣磨力数学模型与铣磨实验结果符合铣磨力变化规律,数值上平均误差为5.6%;铣磨力随着主轴转速提高有显著降低并趋于平缓趋势,而随着铣磨进给速度与铣磨深度增大,铣磨力呈线性增加;铣磨夹角从45°增至75°,切向和法向铣磨力增大了数倍,轴向铣磨力仅增大50%,因此,加工时应选择较小的铣磨夹角。     

旋转超声电解复合加工小孔流场仿真

为解决电解加工深小孔中电解液难以进入加工区和电解产物难以排出的问题,构建了内喷式旋转超声电解复合加工装置,进行了电解加工、旋转电解加工和旋转超声电解复合加工小孔的对比试验。试验结果表明,阴极旋转能明显提高孔的圆度,旋转超声电解复合加工具有最大的平均加工电流,所加工孔的直径、深度都为三者中最大,表明其材料去除率是最大的。在此基础上,利用有限元ANSYS CFX软件,建立了气液两相流三维气穴模型,分析了阴极旋转和阴极高频振动对电解加工流场、电场的影响。仿真结果表明：阴极旋转使得气泡在阴极表面聚集,不利于气泡的排出,阴极振动加速了电解液的运动,有利于气泡的排出,因此具有最大的材料去除率。     

航天发动机叶片电解加工流场设计和试验研究

电解加工作为整体构件制造的主要技术之一,其流场设计的合理性将严重影响电解加工过程的稳定性、加工效率和质量。针对航天发动机叶片式扩压器设计了部分阻隔式反W型流场,并开展了与侧流式和反W型流场的仿真比较。仿真结果表明,该流场方式可以保证加工区电解液的高速流动,并能有效避免进/排气边漏液现象。最后,在部分阻隔式反W型流场中开展了叶片式扩压器电解加工试验,在阴极进给速度为0.5 mm/min时加工出了扩压器叶片,验证了流场设计的合理性。     

球形磨头单颗磨粒铣磨力模型与仿真研究

建立明晰的单颗磨粒铣磨力模型是深入解析球形磨头铣磨加工机理及工程应用的关键.通过分析磨头上单颗磨粒的铣磨过程,考虑磨头偏角的影响,建立了球形磨头上单颗磨粒铣磨力数学模型;对单颗磨粒进行多组铣磨仿真实验,分析铣磨参数对铣磨力的影响规律.结果表明:在磨粒的单次铣磨过程中,铣磨深度从20μm增大至50μm,铣磨力增大了2倍;...     

基于实验Inconel718正交切削有限元仿真分析

为研究犁削效应和前刀面粘压对Inconel718切削过程的影响.基于正交切削实验建立Inconel718有限元切削模型,模型结果同实验值对比以验证模型可靠性.通过改变刀具圆角半径和负前角参数,提取并比较不同的切削力时域曲线和刀具温度,分析犁削效应和前刀面粘压.研究表明犁削效应提高进给力数值,刀具圆角半径由0变为5μm,Inconel718切削进给力均值提高7％：前刀面粘压提高刀具和切屑温度,有利于切屑分离.但刀具负前角为-20＆#176;,切削加工不稳定.     

Inconel718与硬质合金摩擦磨损特性的实验研究

利用UMT-2多功能摩擦磨损试验机对镍基合金Inconel 718与硬质合金刀具对偶时的摩擦磨损特性进行研究,揭示法向载荷和滑动速度对摩擦副摩擦因数的影响,通过SEM观察试样摩擦形貌并分析磨损机制.研究结果表明:摩擦副的摩擦因数随着法向载荷的增大而减小,随滑动速度的增大而增大;Inconel 718镍基合金与硬质合金对偶时的磨损机制主要为黏着磨损、磨粒磨损和氧化磨损.     

切削参数与刀具几何形状对Inconel 718加工残余应力的影响

对Inconel 718高速切削加工过程中合金加工表面的残余应力进行研究,为优化材料切削参数提供参考。由试验结果可知,最大切削速度、最小进给量、中等切削深度和使用珩磨切削刃可以确保减少加工表面的残余应力,相应的表面也没有划痕区和粘附的碎屑。     

Incone1718镍基高温合金的切削性能仿真

在考察Inconel718镍基高温合金的化学成分和有关性能的基础上,通过Deform-3D软件对其进行车削仿真,分析影响Inconel718镍基高温合金切削性能的主要因素,给出其最佳的切削速度、进给量和背吃刀量的组合.研究了不同换热系数和刀-屑摩擦因数对Inconel718镍基高温合金切削性能的影响,找到了恰当的冷却润滑方式.     

Modeling subsurface deformation induced by machining of Inconel 718

Traditionally, the development and optimization of the machining process with regards to the subsurface deformation are done through experimental method which is often expensive and time consuming. This article presents the development of a finite element model based on an updated Lagrangian formulation. The numerical model is able to predict the depth of subsurface deformation induced in the high- speed machining of Inconel 718 by use of a whisker-reinforced ceramic tool. The effect that the different cutting parameters and tool microgeometries has on subsurface deformation will be investigated both numerically and experimentally. This research article also addresses the temperature distribution in the workpiece and the connection it could have on the wear of the cutting tool. The correlation of the numerical and experimental investigations for the subsurface deformation has been measured by the use of the coefficient of determination, R². This confirms that the finite element model developed here is able to simulate this type of machining process with sufficient accuracy.     

高速成型车削镍基合金Inconel718的建模和有限元分析

利用Deform 3D有限元分析软件,模拟成型车削Inconel 718,分析了不同切削深度和切削速度下的切削力及卷屑排屑状况,并对刀具应力及刀具磨损进行了分析。     

Evaluation of the Machinability of Nickel-Base,Inconel 718, Alloy with Nano-Ceramic Cutting Tools

The machinability of difficult-to-cut aerospace alloys can be enhanced by the rapid development of cutting tool materials that can withstand machining at high-speed conditions. The performance of nano-grain size ceramic tool materials were evaluated when machining nickel base, Inconel 718, in terms of tool life, tool failure modes and wear mechanisms as well as component forces generated under different roughing conditions. Comparison tests were carried out with commercially available ceramic tool materials of micron-grain composition.

The test results show that the micron grain size commercially available tool materials generally gave the longest tool life. The dominant failure mode is nose wear, while some of the nano-ceramic tools were rejected mainly due to chipping at the cutting edge. This suggests that physical properties and mechanical stability of the cutting edge of the ceramic tools influence their overall performance. It is also evident that chemical compositions of the tool materials played a significant role in their failure. The alumina base ceramics are more susceptible to premature fracture than the silicon nitride base ceramics with higher fracture toughness.     

镍基合金Inconel718可切削加工性的试验研究

Inconel718是一种高强度耐热镍基合金,具有优良的高温强度、高温硬度和耐蚀性,在高温条件下能长期工作,已被广泛地应用于宇航工业、航空工业的涡轮发动机和相关零件的制造。分析Inconel718的机械性能、微观组织结构及其对切削加工性能的影响并进行了相关的试验验证,在试验数据的基础上,研究Inconel718中含碳量对切削过程中刀具磨损的影响。试验结果表明,Inconel718中含碳量在刀具后刀面磨损中起着非常重要的作用,Inconel718合金中含碳量越高,合金中所含的细微硬质夹杂物也越多,在切削过程中使刀具产生严重的后刀面磨粒磨损,从而降低材料的切削加工性。     

Surface roughness modeling in Laser-assisted End Milling of Inconel 718

Inconel 718 is a difficult-to-machine material while products of this material require good surface finish. Therefore, it is essential for the evaluation and prediction of surface roughness of machined Inconel 718 workpiece to be developed. An analytical model for the prediction of surface roughness under laser-assisted end milling of Inconel 718 is proposed based on kinematics of tool movement and elastic response of workpiece. The actual tool trajectory is first predicted with the consideration of overall tool movement, elastic deformation of tool, and the tool tip profile. The tool movements include the translation in feed direction and the rotation along its axis. The elastic deformation is calculated based on the previously established milling force prediction model. The tool tip profile is predicted based on the tool tip radius and angle. The machined surface profile is simulated based on the tool trajectory with elastic recovery, which is considered through the comparison between the minimum thickness and actual cutting thickness. Experiments are conducted in both conventional and laser-assisted milling under seven different sets of cutting parameters. Through the comparison between the analytical predictions and experimental measurements, the proposed model has high accuracy with the maximum error less than 27%, which is more accurate for lower feed rate with error less than 3%. The proposed analytical model is valuable for providing a fast, credible, and physics-based method for the prediction of surface roughness in milling process.