激光柔性动态冲击成形微碟形零件的研究

发布时间：2018-04-17 08:46

本文选题：复合工艺 + 微零件　；参考：《江苏大学》2017年硕士论文

【摘要】：随着零件轻量化和微型化的发展,市场对于微型器件的需求日益增加,各种微成形工艺相继涌现出来,如微拉深、微弯曲、微冲裁、微压印等。制造涉及多种工艺的微零件时则需要使用级进模以及复合模。但由于模具制造困难、取出操作性差以及冲头与凹模的对中等问题,使得微零件的尺寸始终限制在一定的范围内。本文利用激光柔性动态冲击成形技术,制造出一种可用作垫片,外环直径为1.4mm的微碟形零件,实现了微拉深、微冲裁与微落料的复合工艺。通过微复合模具的可行性探究、实验研究和微碟形零件成形过程的数值模拟分析了激光柔性动态冲击成形微碟形零件的技术,主要的工作内容和成果如下:(1)建立了激光柔性动态冲击成形微碟形零件的实验平台,设计了齐高度微复合凹凸模、半高度微复合凹凸模和微复合凹模这三种不同的微复合模具。在T2紫铜材料上完成了微碟形零件的制造。利用基恩士三维显微镜观察成形形貌,对成形性能、工艺完成顺序、工艺完成度以及零件可取出性这四个方面进行分析。对于齐高度微复合凹凸模,复合工艺均可完成,但冲裁断面的质量较低,微碟形零件较难从模具中取出;对于半高度微复合凹凸模,微冲裁工艺不能完成,微碟形零件仍然较难从模具中取出;对于微复合凹模,复合工艺均可完成,工艺完成顺序为微拉深,微冲裁,微落料,具有较好的表面形貌和断面质量,微零件能够从模具中取出,因此微复合凹模较适合用来制造微碟形零件。(2)利用微复合凹模进行实验,对微碟形零件的成形高度、微冲裁的质量、工艺类型对尺寸精度的影响、微零件的厚度、软模厚度对成形过程的影响进行了讨论,测试并分析了表面粗糙度和试样的硬度。通过对成形高度的测量,发现成形高度随着激光能量的增加先增大后减小。利用三维光学显微镜和扫描电子显微镜SEM对零件的直径尺寸和断面进行分析,发现微冲裁的直径尺寸随着激光能量的增加先增大后减小。在高应变率加载下,断面出现了较大的圆角带,没有明显的光亮带和断裂带。而单独冲裁微孔时出现了较小的圆角带、光亮带与毛刺,与复合工艺产生了差异。微冲裁与微落料的尺寸精度随着激光能量的变化趋势类似,但微冲裁的尺寸精度为负值,微落料的尺寸精度为正值。(3)研究了材料特性、模具特征和激光能量对工件材料的厚度分布规律的影响,T2紫铜和304不锈钢的最大减薄率都出现在颈部区域,最小减薄率分别出现在中间区域和法兰区域。在相同的激光能量下,当软模厚度增加时,工件的成形过程出现了明显的滞后现象。利用Axio CSM700测量不同区域的Ra值,发现法兰区域和颈部区域的表面粗糙度值随着激光能量的增大而增加,仅在微落料工艺完成后发生了骤降,而底部区域的表面粗糙度值随着激光能量的增大而减小。通过纳米硬度测试发现,T2紫铜与304不锈钢的纳米硬度较原材均有提高,平均硬度值均在颈部区域提升最多。(4)使用ANSYS/LS-DYNA软件对激光柔性动态冲击成形微碟形零件的过程进行了数值模拟,探究了模具特征对工艺顺序的影响、软模厚度对成形过程的影响以及成形过程中的回弹,进一步解释了制造过程中的变形行为。
[Abstract]:With the development of lightweight parts and miniaturization, the market demand for micro devices is increasing, a variety of micro forming technology have emerged, such as micro deep drawing, bending, micro blanking, Microimprint. Manufacturing process involves a variety of micro parts when you need to use a progressive die to die. But because the mold and composite manufacturing difficulties, poor operation and remove the punch and die on the medium, so that the micro parts size is always limited to a certain range. By using the laser shock forming flexible dynamic technology, manufacturing a gasket can be used as the outer ring, the diameter is 1.4mm micro disc shaped parts, realize micro deep drawing. Micro blanking and micro composite materials. Through the fall process feasibility of micro composite mold research, experimental research and micro disc parts forming process numerical simulation of laser flexible dynamic impact micro disc parts forming, the main work The contents and results are as follows: (1) the establishment of a flexible dynamic laser shock forming micro disc parts of the experimental platform, design the Qi height micro composite die, half height micro compound punch die and micro composite die of the three different micro composite mold. Manufactured micro disc parts in T2 copper materials. Morphology observation by Kean, forming three-dimensional microscope on the forming performance, process order, process and parts can be taken out of the four were analyzed. For the height of micro embossing composite, composite process can be completed, but at the cutting quality is low, micro disc parts are difficult to remove from the mold in the half height; micro composite die, micro blanking process can not be completed, micro disc parts are still difficult to remove from the mold; for the micro composite die, composite process can be completed, completed in order for the micro deep drawing process, micro blanking, micro drop With material, surface morphology and good quality, the micro parts can be removed from the mold, so micro composite die was suitable for manufacturing micro disc parts. (2) experiments using micro composite die for forming height micro disc parts, the quality of micro blanking process, influence the type of the size accuracy of micro parts, the thickness of soft mold thickness are discussed on the forming process, the test and analysis of the surface roughness and hardness of the samples. The forming height measurement, found forming height with the increase of the laser energy increases first and then decreases. The diameter size and cross section of parts by using three-dimensional optical microscope scanning electron microscopy and SEM analysis, found that the micro blanking diameter with the increase of the laser energy increases first and then decreases. At high strain rate loading section, a larger round belt, no obvious bright band and broken Fracture belt and micro blanking alone appeared smaller fillet with light, belt and burr, makes the difference and combination technology. Micro blanking and micro drop size precision laser energy material with the change trend is similar, but the size precision of micro blanking is negative, micro drop size precision of the material is positive. (3) studied the effect of material properties, mold characteristics and laser energy on the workpiece material thickness distribution, maximum thickness thinning of T2 copper and 304 stainless steel have appeared in the neck region, the minimum reduction rate were found in the middle region and the flange area. Under the same laser energy, when the thickness of the soft mold when increasing the forming process of workpiece has a obvious hysteresis. Using Axio CSM700 to measure the Ra values in different regions of the surface, flange area and neck region roughness value increases with the increase of laser energy, only in the micro blanking process is completed The dips, and the surface roughness of the bottom area decreases with the increase of laser energy. The nano hardness test showed that T2 copper and 304 stainless steel raw material nano hardness is increased, the average hardness value in the neck region up. (4) using the ANSYS/ LS-DYNA software of laser shock forming flexible dynamic process the micro disc shaped parts was simulated and the influence of the characteristics of the mould process sequence, the thickness of the soft mold forming process and springback in the forming process, further explains the deformation behavior of the manufacturing process.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG665

【参考文献】