三维金属微结构模具的叠层拟合成形与应用

发布时间：2017-12-30 21:49

本文关键词：三维金属微结构模具的叠层拟合成形与应用　出处：《深圳大学》2015年博士论文　论文类型：学位论文

【摘要】：随着微机电系统(MEMS)的发展和应用,微制件已广泛应用于微电子器件、精密机械、生物医疗以及航空航天等领域。微制件的结构尺寸微小,重量极轻,很难用普通加工方法对其加工。随着国际该领域研究的深入,出现了一系列面向微制件的微细加工技术:例如LIGA/UV-LIGA、微细电火花、微细电解、双光子成形以及飞秒激光微细加工技术等。上述工艺对微制件的制备做出了较大贡献,但对于制备含复杂特征的三维金属微结构均存在各自的技术瓶颈。本文针对上述技术瓶颈,在国家自然科学基金(No.51175348、51375315、51405306)的资助下,遵循“化整为零,拟直逼曲,以简代繁,积零为整”的微积分学术思想,提出三维金属微结构模具的叠层拟合成形工艺。该方法以分层实体制造工艺(LOM)和微型双工位叠层成形方法(Micro-DLOM)为基础,通过多层二维金属微结构叠层拟合成形三维金属微模具,围绕二维金属微结构精密成形、形位公差精确控制、三维金属微模具重构等关键技术开展系统研究,较好地解决了具有复杂曲面特征和深宽比不受限制的三维微结构的加工科学问题,成功制备了金属箔微胀形件和微小型塑件。三维金属微型腔模具、金属微胀形件以及微小型塑件的成功制备验证了该工艺的可行性和先进性,开创了三维金属微型腔模具制造的新领域。本文的主要研究内容如下:(1)通过双温模型结合有限差分的Crank-Nicolson方法对飞秒激光烧蚀金属箔的一维温度场进行了数值模拟,从而为飞秒激光烧蚀金属箔,控制精密二维金属微结构成形提供理论依据。研究发现材料的电子和飞秒激光的光子相互作用时,存在一个饱和功率密度和饱和时间。同时对影响材料电子—晶格能量耦合时间的因素进行了分析,发现激光能量密度和电子—晶格能量耦合参数是对电子—晶格能量耦合时间产生影响的主要因素。(2)在叠层模具制造过程中,为了切割方便,将待加工金属箔的另一端向上弹性弯曲,正加工金属箔平铺,已加工金属箔向下弹性弯曲,这种创新性的弯曲结构有利于废料的自动脱落。本文也对这种弯曲结构的金属箔变形情况进行了分析。(3)采用上述金属箔弯曲结构,对二维金属箔飞秒激光切割与三维金属微型腔模具微细电阻滑焊组合重构工艺进行了系统研究,提出了最佳工艺参数。以10μm厚的0Cr18Ni9不锈钢箔为模具基材,在120m W的飞秒激光功率、50μm/s的切割速度以及0.75μm的切割补偿量,0.21V的焊接电压,0.2MPa的焊接压强,100ms的预压时间,10ms的放电时间以及160次滑焊放电情况下,利用该工艺制备了尺寸精度和表面质量好的二级、三级阶梯金属微齿轮腔模具。(4)提出线切割与热扩散焊组合方法制备三维金属微模具工艺。通过线切割实验研究了线切割放电电压、放电电流、脉冲宽度以及脉冲间隔对二维金属箔切割质量的影响规律;通过真空压力热扩散焊实验研究了热扩散时间以及热扩散压力对三维金属微模具重构焊接质量的影响规律,从而获得一组较好的工艺参数用于制备表面质量、尺寸精度和整体机械性能较好的微模具。(5)通过实验研究了超声波功率、超声波作用时间以及超声波压强对金属微成形件、微小型塑件成形质量的影响规律,获得较优的超声波工作参数。利用叠层拟合成形工艺制造的三维金属微凹模型腔,应用超声波塑化叠层模具腔内粉末、驱动熔融树脂胀形制备了T2紫铜箔微结构件。该工艺方法所制备的微胀形件的结构尺寸主要取决于凹模。与传统工艺相比,该工艺不存在凹凸模定位不准的问题。以叠层工艺制备的三维金属微模具为凹模,采用超声塑化熔融聚合物粉末颗粒(micro-UPM)的方法制备了微小型塑件,并对凹模内超声塑化熔融过程的作用机理进行了分析。
[Abstract]:With the development of microelectromechanical system (MEMS) development and application of micro parts has been widely used in microelectronics, precision machinery, medical and aerospace fields. The structure size of micro parts is small, light weight, difficult to work with ordinary processing methods on the research in this field. With the deepening of international, the micro machining a series of techniques for micro parts such as: LIGA/UV-LIGA, micro EDM, micro electrolysis, two-photon forming and femtosecond laser micromachining technology. The process of preparation of micro parts to make a greater contribution, but for the preparation of three-dimensional metal containing complex characteristics of micro structures are found. According to their technical bottleneck the technical bottleneck in the National Natural Science Foundation (No.511753485137531551405306) funding, follow the "quasi hit song, to break up the whole into parts, in behalf of the fan, accumulating the academic thought of calculus Think of laminated fitting forming process of metal micro structure mould is proposed. This method in LOM Process (LOM) and micro double stacked molding method (Micro-DLOM) as the foundation, through multi-layer two-dimensional metal micro structure of laminated metal fitting forming 3D micro mold, metal micro structure around the two-dimensional shape of precision forming the precise control of position tolerance system, researching on the key technologies of 3D reconstruction of micro metal mold, solved with complex surface features and wide deep processing science problems than unrestricted three-dimensional micro structure, fabricated metal foil micro bulging parts and micro plastic parts. 3D micro metal mold cavity. Metal micro bulging parts and micro plastic parts were successfully prepared to verify the feasibility of the technology and advanced, and created a new field of 3D micro metal mold manufacture. The main research contents of this paper are as follows: (1) through The two temperature model with Crank-Nicolson finite difference method of one-dimensional temperature field of femtosecond laser ablation of metal foil was simulated to femtosecond laser ablation of metal foil, the control precision of two-dimensional metal micro structure forming and provide a theoretical basis. The study found the electronic materials and femtosecond laser photon interactions, the existence of a saturated power the density and saturation time. At the same time, the influence factors of electron lattice coupling time energy materials were analyzed, found that laser energy density and electron lattice coupling energy parameters are the main factors influence the electron lattice energy coupling time. (2) in the laminated mould manufacturing process, in order to facilitate the cutting, the other end the processing of metal foil to the elastic bending processing, metal foil tile, machined metal foil elastic bending bending down, this innovative structure is beneficial to waste The automatic fall off. The metal foil on this structure bending deformation was analyzed. (3) the structure of two-dimensional curved metal foil, metal foil femtosecond laser cutting were studied with 3D metal micro cavity mold micro resistance welding combined sliding reconstruction process, the optimum parameters in 0Cr18Ni9 stainless steel foil. 10 m thick mold base, in the femtosecond laser power of 120m W, the cutting speed is 50 m/s and cut compensation amount of 0.75 m, voltage 0.21V welding, welding pressure 0.2MPa, 100ms preloading time, 10ms discharge time and the 160 slip welding discharges, preparation the size accuracy and surface quality of the two level by this process, three steps of metal micro gear cavity die. (4) proposed line cutting and heat diffusion welding combination preparation method of metal micro mould process. Experimental study on the cutting line by line cutting Electric voltage, discharge current, influence of pulse width and pulse interval on the two-dimensional cutting quality of metal foil by vacuum diffusion welding; thermal stress experiment of thermal diffusion and thermal diffusion time pressure on metal micro mold reconstruction of the welding quality, so as to obtain a better set of process parameters for the preparation of the surface quality. The size of the overall accuracy and good mechanical properties of micro mold. (5) through the experimental study of ultrasonic power, ultrasonic time and ultrasonic pressure on metal micro forming, micro plastic forming quality of the influence of ultrasonic parameters better. Forming three-dimensional metal manufacturing process of micro cavity using stack fitting, application of ultrasonic plasticizing laminated mould cavity powder, driving the molten resin bulge forming T2 copper foil micro structure. The micro expansion process for preparing shaped parts The structure size depends on the die. Compared with the traditional process, this process does not exist die positioning problem. Based on 3D metal laminate preparation for micro mould die, using ultrasonic plasticizing melt polymer powder particles (micro-UPM) were prepared by means of micro plastic parts, and the mechanism of the melting process of ultrasonic plasticizing die are analyzed.

【学位授予单位】：深圳大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG76;TH-39

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