管电极电解加工深小孔技术研究

发布时间：2017-12-31 03:25

本文关键词：管电极电解加工深小孔技术研究　出处：《大连理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：深小孔在航天、武器、机械、医疗及仪器等领域应用广泛。目前深小孔一般采用机械钻削、激光、电火花等方法加工,但传统的机械加工存在热变形、难以加工高强度及高硬度材料等问题,而激光加工和电火花加工则会生成重铸层和微裂纹等缺陷。管电极电解加工技术无冷作硬化层、电极损耗、热再铸层、孔口没有毛刺和飞边,且其加工范围不受材料强度、硬度、韧性、熔点、导热性等的限制。因此,采用管电极电解加工技术加工深小孔具有重要研究价值。本文设计并搭建了管电极电解加工深小孔加工装置：试验装置选择工件固定、电极进给的加工方案,利用双滚轮的挤压作为进给方式；进给装置采用基于PLC的驱动控制,通过编程实现不同进给速度控制；采用正流式的电解液流动方式并设计了电极夹具；为提高加工精度,选用矩形波脉冲电源作为加工电源；在深小孔出口处设计了防泄保压结构,以避免短路现象,提高加工稳定性；利用基于FA-8树脂的有机涂层工艺来实现侧壁绝缘,能有效改善深小孔的锥度问题。利用COMSOL Multiphysics软件对加工间隙进行流场仿真,通过不同仿真参数的设置和仿真结果,分析进口压力与加工稳定性之间的关系。试验表明,电解液进口压力过小或过大均易导致加工稳定性变差,最终确定电解液的进口压力为0.4MPa。开展管电极电解加工深小孔试验,研究了电流、脉冲频率、占空比和进给速度对孔加工质量的影响规律,并分析了各加工参数对孔表面粗糙度、径向过切量和锥度的影响程度。结果表明,在进给速度为0.66 mm/min、电流为1.5 A、脉冲频率为10 kHz,占空比为0.5时,加工效果较好。加工出了平均直径为1.962 mm、深为30 mm的深小孔,深径比达15.3,粗糙度为1.081 μm,锥度为0.074°。采用更长的工件以及FA-8树脂的侧壁绝缘工艺的电极,可加工出平均直径1.939 mm、深60 mm、孔内壁粗糙度Ra 1.349μm、锥度0.092°、深径比达31的深小孔。
[Abstract]:Deep holes are widely used in spaceflight, weapons, machinery, medical treatment and instruments. At present, deep holes are generally machined by mechanical drilling, laser, EDM and other methods, but the traditional mechanical processing has thermal deformation. It is difficult to process high strength and high hardness materials, while laser machining and EDM will produce defects such as recast layer and micro crack. Tube electrode Electrochemical Machining (ECM) technology has no cold hardening layer, electrode loss and hot recasting layer. There are no burrs and flashes at the orifice, and the processing range is not limited by the strength, hardness, toughness, melting point, thermal conductivity, etc. It has important research value to use tube electrode electrolysis machining technology to machining deep small hole. This paper designs and builds the tube electrode electrolysis machining device for deep small hole: the test device selects the machining scheme of fixed workpiece and electrode feed. The double roller extrusion is used as the feed mode; The feed device adopts the drive control based on PLC and realizes the control of different feed speed by programming. The electrode clamp was designed by using positive flow electrolyte flow mode. In order to improve the machining accuracy, the rectangular pulse power supply is selected as the machining power source. In order to avoid the phenomenon of short circuit and improve the processing stability, the pressure relief structure is designed at the outlet of deep hole. The side wall insulation is realized by organic coating process based on FA-8 resin. It can effectively improve the taper problem of deep holes. The flow field of machining clearance is simulated by COMSOL Multiphysics software, and the simulation results are obtained by setting different simulation parameters. The relationship between inlet pressure and processing stability is analyzed. The test results show that too small or too large inlet pressure of electrolyte will lead to poor processing stability. Finally, the inlet pressure of electrolyte was determined to be 0.4 MPA. The experiment was carried out to study the influence of current, pulse frequency, duty cycle and feed speed on the hole machining quality. The influence of machining parameters on the surface roughness, radial overcut and taper is analyzed. The results show that the feed speed is 0.66 mm / min and the current is 1.5 A. When the pulse frequency is 10 kHz and the duty cycle is 0.5, the processing effect is better. The average diameter is 1.962mm and the depth is 30mm. The deep diameter Prida is 15.3. The roughness is 1.081 渭 m and the taper is 0.074 掳. The average diameter of the electrode with longer workpiece and FA-8 resin is 1.939mm. Deep 60mm, roughness Ra 1.349 渭 m, taper 0.092 掳, deep diameter Prida 31 deep hole.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG662

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