共查询到19条相似文献,搜索用时 109 毫秒
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激光冲击软模大面积微弯曲成形方法 总被引:1,自引:0,他引:1
为了实现金属箔板大面积微弯曲成形,本文结合激光冲击微弯曲成形技术与软模成形技术的优点,提出了激光冲击软模大面积微弯曲成形方法。 该方法是在脉冲激光冲击波压力下,将软模作为柔性冲头作用于金属箔板来实现工件成形的。实验中使用了Innolas Gmbit公司生产的Spitlight 2000 THG脉冲激光器,将250 μm厚的聚氨酯橡胶薄膜作为软模,采用德国LPKF-ProtoMat-C60型雕刻机在印刷电路板上加工出深度为120 μm的U型多槽模具,实现了在厚度为30 μm的铜箔板上一次性对3个U型凹槽冲击成形。用KEYENCE VHX-1000C超景深三维显微系统进行工件观测,结果显示工件上的微成形槽具有良好的轮廓质量。以ANSYS/LS-DYNA为平台,使用有限元建模(FEM)方法对微弯曲过程进行了数值模拟。实验和模拟结果均表明,加载软模的工件与模具的U型凹槽特征在形状上更加接近,成形工件更加均匀,而且具有较好的表面质量,其最大平均成形深度可达110 μm,大于激光直接冲击成形的最大深度(88 μm),说明使用软模提高了充型能力。 相似文献
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激光弯曲成形是一种利用激光成形工件的柔性成形技术.建立了钛箔激光微弯曲成形的三维热力耦合有限元模型,采用大型非线性有限元软件ANSYS对其激光微弯曲过程进行了有限元模拟.通过模拟计算得到了钛箔激光微弯曲过程的温度场和位移场分布.结果表明:钛箔上下表面存在温度梯度,但由于钛箔厚度薄,热传导迅速,导致其z向位移出现波动. 相似文献
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激光冲击驱动飞片成形性能 总被引:1,自引:0,他引:1
研究了激光冲击驱动飞片成形中相关工艺参数对成形性能的影响。采用适合高压高应变率的Johnson-Cook模型,基于ANSYS/LS-DYNA软件平台,数值模拟了激光冲击驱动飞片成形胀形件过程中激光能量、成形模具孔径以及模具圆角率与成形件成形高度的关系。分析表明,随着激光功率密度、成形模具孔径和模具圆角率的增加,胀形件成形高度均随之增加,胀形件的最大成形高度为310.6μm。对厚度为50μm的铜箔材进行了激光冲击驱动飞片成形实验,利用体视显微镜和形貌测量仪对获得的胀形件试样进行了二维和三维形貌测试,验证了数值模型的合理性。本文建立的数值模拟分析方法为激光冲击驱动飞片成形胀形件过程的预测和控制提供了手段。 相似文献
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激光冲击成形集板材成形和材料改性于一体,利用激光诱导高幅冲击波的力效应使板料产生塑性变形,是一种无模、柔性成形新工艺。本文使用商业有限元分析软件ABAQUS进行了钛合金板料激光冲击成形过程的仿真研究,分析了钛合金板料厚度、激光能量、约束孔径、激光光斑间隔四种因素对材料变形量和应力应变的影响。研究表明:随着板料厚度的增加,板料变形范围逐渐减小,变形量先减小后增大;随着激光能量的增大,材料的变形量线性增加;激光约束边界孔径越大,板料变形量越大;适当的光斑间隔并不会对零件成形精度造成较大影响,在满足精度要求的条件下,为提高效率可以考虑采用间隔光斑进行冲击成形。 相似文献
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双曲度飞机蒙皮拉伸成形轨迹优化与验证 总被引:1,自引:0,他引:1
加载轨迹是决定飞机蒙皮拉伸成形质量的关键因素。对某双曲度蒙皮最大截面采用应变控制的方法,解析分析并推导出拉伸成形加载轨迹范围,并作为初始加载轨迹进行优化;采用最优化理论与算法和有限元数值模拟相结合的优化方法,以减小卸载回弹、提高贴模度为研究目标,以单元最大,主应变和厚度减薄率为约束条件,建立最优化数学模型,得到合理的拉伸成形加载轨迹;在自行研制的拉伸成形试验平台上进行优化结果验证,试验结果表明,成形零件贴模度、应变分布与厚度的均匀程度均有明显提高。 相似文献
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A system for the launch of hypervelocity flyer plates has been developed and characterized. Laser-driven flyers were launched from the substrate backed aluminum-alumina-aluminum sandwiched films. A laser-induced plasma is used to drive flyers with typical thickness of 5.5 μm and diameters of less than 1 mm, to achieve velocities of a few km/s. These flyer plates have many applications, from micrometeorite simulation to laser ignition. The flyer plates considered here have up to three layers: an ablation layer, to form plasma; an insulating layer; and a final, thicker layer that forms the final flyer plates. This technique was developed aiming at improving the energy efficiency of the system. The kinetic energy of flyers launched with the additional layer was found to be enhanced by a factor of near 2 (up to 30%). The optical fiber delivery system governs the output spatial profile of the laser spot and power capacity. Moreover, a technique for coupling high-power laser pulses into an optical fiber has been developed. This fiber optic system has been successfully used to launch flyer plates, and the surface finishing quality of the fiber was found to be an important factor. Importantly, measurements of the flyer performance including the mean velocities and planarity were made by an optical time-of-arrival technique using an optical fiber array probe, demonstrating the good planarity of the flyer and the achievable average velocity of 1.7 km/s with approaching 1 mm diameter. Finally, the relationship between flyer velocities and incident laser pulses energy was also investigated. 相似文献
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针对微成形技术中存在的脱模问题,提出利用激光冲击波在模具与工件界面上产生界面力进行脱模的新工艺。根据冲击波在介质中传播的特点,分别从冲击波垂直入射、冲击波脱模压力的计算、冲击波斜入射的角度讨论激光冲击波脱模的机理;然后在LS-DYNA软件中进行数值模拟,分析工件从模具上脱落的过程,并进一步讨论在一定冲击波压力下工件的脱模性能;最后按照数值模拟条件进行脱模实验,证实激光冲击波脱模的可能性。 相似文献
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应用分层设计与制备工艺得到了具有微小多层型腔的复杂硅模具,采用坯料直径为3mm的Zr41.2Ti13.8Cu12.5Ni10Be22.5非晶合金为实验材料,使用自行设计的实验平台,对双层微小齿轮(大齿轮模数0.05mm,齿数36,厚度150μm;小齿轮模数0.05mm,齿数30,厚度150μm;中心轴孔直径0.8mm)进行了超塑性成形工艺研究,优化了零件成形、腐蚀脱模、飞边去除及质量分析的工艺流程。结果表明,该工艺流程合理可靠,制备出的Zr基双层微小齿轮保持了非晶态结构、形状完整、充型率高、表面质量良好。 相似文献
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飞秒激光切割与微细电阻滑焊组合制备三维金属微结构 总被引:3,自引:3,他引:0
提出了一种采用飞秒激光切割结合微细电阻滑焊制备3D金属微结构的工艺方法(微型化双工位金属箔叠层制造法,(Micro-DLOM)),并通过制备具有复杂形状的3D微型腔模具验证了该工艺方法的可行性。首先,以厚度为10μm的0Cr18Ni9不锈钢箔为基材,在110mW的飞秒激光功率、100μm/s的切割速度和0.75μm的切割补偿量下获得二维微结构,并分析了激光功率和切割速度对切割精度的影响;然后,利用微细电阻滑焊对多层二维微结构进行热扩散焊接,通过多层二维微结构的叠加拟合形成具有曲面特征的微型腔,并对焊接区进行了X射线衍射(XRD)分析。分析发现:微细电阻滑焊所产生的热量仅使焊接区主要物相的相对含量发生了变化,而没有使该区域产生新的物相。与UV-LIGA工艺相比,本工艺可以加工具有自由曲面特征的三维微结构,并且单层钢箔越薄,成形精度越高;与飞秒激光分层平面扫描烧蚀工艺相比,本工艺仅需切割每层二维结构的轮廓,提高了成形效率;与微细电火花加工工艺相比,虽然所成形的微型腔表面粗糙度相对较差,但却省去了制备微电极的工艺步骤,并且不存在微电极工作过程中的损耗问题,所以可以加工深宽比不受限制的微模具。 相似文献
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Wang G He J Zhao J Tan F Sun C Mo J Xong X Wu G 《The Review of scientific instruments》2011,82(9):095105
Electrical explosion of metallic foil or wire is widely used to the fields of material science (preparation of nao-meter materials), dynamics of materials, and high energy density physics. In this paper, the techniques of gaining hypervelocity flyer driven by electrical explosion of metallic foil were researched, which are used to study dynamics of materials and hypervelocity impact modeling of space debris. Based on low inductance technologies of pulsed storage energy capacitor, detonator switch and parallel plate transmission lines with solid films insulation, two sets of experimental apparatuses with storage energy of 14.4 kJ and 40 kJ were developed for launching hypervelocity flyer. By means of the diagnostic technologies of velocity interferometer system for any reflectors and fibre-optic pins, the hypervelocity polyester (Mylar) flyers were gained. For the apparatus of 14.4 kJ, flyer of diameter φ6 ~ φ10 mm and thickness of 0.1 ~ 0.2 mm was accelerated to the hypervelocity of 10 ~ 14 km/s. And for the apparatus of 40 kJ, flyer of diameter φ20 ~ 30 mm and thickness of 0.2 mm was launched to the velocity of 5 ~ 8 km/s. The flatness of the flyer is not more than 34 ns for the flyer with diameter of 20 mm, and less than 22 ns for the flyer with diameter of 10 mm. Based on the Lagrange hydrodynamic code, one dimensional simulation was done by introducing database of equation of states, discharging circuit equation and Joule heat equation, and modifying energy equation. The simulation results are well agreed with the experimental results in accelerating processing. The simulation results can provide good advices in designing new experiments and developing new experimental devices. Finally, some experiments of materials dynamics and hypervelocity impact of space debris were done by using the apparatus above. The results show that the apparatus of metallic foil electrically exploding driving hypervelocity flyer is a good and versatile tool for shock dynamics. 相似文献
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Chaojun Yang Zhen Ye Jinzhong Lu Yinfang Jiang 《The International Journal of Advanced Manufacturing Technology》2011,56(9-12):987-993
A novel forming method by laser shock wave with elliptical spot is reported. The mechanism of laser shock forming (LSF) and equation of pressure pulse were presented, and SUS304 stainless steel with a thickness of 0.4?mm was experimentally investigated. Firstly, the deformed specimen was measured by ARGUS optical measuring system, and the results of major and minor strain and material thickness reduction of sheet metal to analyze the deformation qualities were provided. Secondly, the major and minor strains were imported into forming limit diagram (FLD) to evaluate the forming parameters. The result clearly shows that all measurement points are below the forming limit curves of the SUS304 steel. Finally, the thickness reduction along long-axis direction was simulated and analyzed by using ABAQUS finite element (FE) software. The simulated results are basically in agreement with the experiment data. 相似文献
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Chelsey Pence Hua Ding Ninggang Shen Hongtao Ding 《The International Journal of Advanced Manufacturing Technology》2013,69(1-4):319-327
Laser shock bending is a sheet metal micro-forming process using shock waves induced by a nanosecond-pulsed laser. It is developed to accurately bend, shape, precision align, or repair micro-components with bending angles less than 10°. Negative bending angle (away from laser beam) can be achieved with the high-energy pulsed laser, despite the conventional positive laser bending mechanism. In this research, various experimental and numerical studies on aluminum sheets are conducted to investigate the different deformation mechanism, positive or negative. The experiments are conducted with the sheet thickness varying from 0.25 to 1.75 mm and laser pulse energy of 0.2 to 0.5 J. A critical thickness threshold of 0.7-0.88 mm is found that the transition of positive–negative bending mechanism occurs. A statistic regression analysis is developed to determine the bending angle as a function of laser process parameters for positive bending cases. 相似文献
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Bin Xu Xiao-yu Wu Shi-quan Ling Feng Luo Chen-lin Du Xiu-quan Sun 《The International Journal of Advanced Manufacturing Technology》2013,66(5-8):601-609
This paper proposes a novel fabrication process based on femtosecond laser cutting and micro-electric resistance slip welding to address the bottleneck presented by ultraviolet–Lithographie, Galvanoformung, Abformung combined with micro-electroforming, in which micro-molds are usually fabricated with vertical wall structures. At first, 10-μm thick 0Cr18Ni9 stainless steel foils were cut by femtosecond laser to obtain several single-layer graphics which were then joined by micro-electric resistance slip welding. The slip welding process formed a 3D micro-structure and the weld zone of micro-structure was tested by the X-ray diffraction (XRD). The XRD results show that the phases of weld zone remain unchanged, but that the phase content slightly changes. Finally, a 3D metal micro-structure mold was processed under 110 mW femtosecond laser power, 0.1 mm/s cutting speed, 0.21 V welding voltage, 10 ms welding time, 0.2 MPa welding pressure, 0.5 mm bar electrode diameter, 160 time’s slip welding discharge, which proves that the forming process could be a useful method for the production of 3D micro-molds. 相似文献