YB_10287_朱增伟_ZY

附件1 附件4 作者姓名：朱增伟 论文题目：磨擦辅助精密电铸技术的研究与应用 作者简介：朱增伟，男，1971年3月出生，2003年4月师从于南京航空航天大学朱荻教授，于2008年4月获博士学位。 中 文 摘 要 电铸技术是根据电化学沉积原理，通过尺度极其微小的金属离子在芯模（阴极）表面还原结晶而成形零件的特种加工技术，具有复制精度高、重复精度高、 材料 关于××同志的政审材料调查表环保先进个人材料国家普通话测试材料农民专业合作社注销四查四问剖析材料 性能可控等优点。电铸主要用于传统方法难以加工或加工成本过高的金属零件精密成形，在美国、德国等工业发达国家受到高度重视，已经在航天、航空、兵器、电子等高科技领域用于制造多种关键零部件，例如火箭喷管、破甲弹药型罩、光学镜面、微波波导管、大型RF谐振腔的铜衬套、模具等零件的制造。对于某些具有特殊要求的精密零件来说，如液体火箭发动机推力室身部的镍外壁，电铸技术是唯一可行的制造方法。 然而，从国内外的研究现状来看，现有的电铸技术仍然存在着一些关键问题难以解决，如针孔、麻点和结瘤等缺陷、晶粒粗大、生产周期长等，严重制约着电铸技术的发展。伴随金属沉积发生的析氢反应产生氢气泡吸附在阴极表面，会导致针孔和麻点的产生；而沉积表面某些微突起的优势生长则会导致结瘤的产生。随着电铸过程的持续进行和零件壁厚的逐渐增加，结瘤等缺陷会迅速长大，进而导致电铸材料性能下降，严重时会迫使电铸中止，甚至产生废品。在常规电铸中，电铸层晶粒多在微米量级，材料性能不够理想，在某些场合不能满足实际需求。受阴极极限电流密度的限制，电铸速度一般较低，生产周期长。可见，如何切实提高电铸零件的质量和性能，提高电铸速度，缩短电铸周期，是当前急需解决的难题。 本文提出磨擦辅助精密电铸技术，即在金属电沉积的同时，采用不导电的游离粒子对正在生长的沉积层进行微量磨削，同时影响电沉积过程，以提高电铸层质量和电铸速度。本文通过理论分析和试验研究，探索磨擦辅助电铸的机理，重点揭示游离粒子磨擦对电铸层表面质量、组织结构、材料性能及电铸速度的影响规律；研制磨擦辅助精密电铸机床，开展磨擦辅助精密电铸技术的应用研究。具体研究内容包括以下几方面： （一）游离粒子磨擦在电铸过程中的驱氢作用研究 在分析电铸析氢反应及其对电铸层影响的基础上，重点研究磨擦辅助电铸中游离粒子磨擦的驱氢作用。通过电铸镍和电铸铜试验，研究所制备电铸层的外观形貌和孔隙率。结果表明，游离粒子在电铸过程中通过机械驱除作用阻止氢气泡的吸附，并通过提高阴极析氢过电位减少析氢量。试验发现，游离粒子磨擦能彻底消除析氢的不利影响，利用磨擦辅助精密电铸技术能够制造出没有任何麻点、针孔等缺陷的镍电铸层。 （二）游离粒子磨擦对电铸层表面的整平作用研究 分析游离粒子在磨擦辅助电铸过程中运动和力的作用特点，揭示游离粒子对沉积层的整平机理，研究不同工艺参数下所制备电铸层的表面粗糙度和微观表面形貌的变化。理论分析表明，游离粒子磨擦对正在沉积的电铸层具有微量磨削作用，能有效去除表面结瘤，整平微观形貌，提高表面光亮度。试验取得了满意结果： 1．电铸层微观形貌呈现明显的磨削痕迹，而且随着阴极速度的提高，游离粒子的作用加强，磨削痕迹更加明显。 2．所制备的镍电铸层表面光亮平整、接近镜面效果，无任何结瘤或凹坑，表面粗糙度低于Ra0.02 m。提高阴极速度有利于降低电铸层的表面粗糙度。 （三）游离粒子磨擦改善电铸层组织结构的机理分析与试验研究 从理论和试验两方面研究游离粒子磨擦影响电铸层组织结构的机理和现象。 理论分析表明，游离粒子在金属电沉积的同时磨擦沉积层表面，有助于提高阴极过电位，使沉积层晶粒细化；并影响晶粒各晶面的生长速度，使沉积层的结晶形态发生变化。 试验结果显示，与常规电铸技术相比，用磨擦辅助精密电铸技术所制备的镍电铸层和铜电铸层的组织结构均发生明显变化。以镍电铸层为例，各晶面的衍射强度降低，择优程度明显改变，晶粒尺寸显著减小，可制备出晶粒小于80 nm的镍电铸层。 （四）磨擦辅助电铸材料的性能测试与分析 对磨擦辅助电铸所制备电铸层的材料性能进行测试，并对结果予以分析，研究电铸层的材料性能随工艺参数的变化规律及其与组织结构的关系。研究发现： 1．与常规电铸技术相比，用磨擦辅助精密电铸技术所制备电铸层的材料性能显著提高。电铸镍的显微硬度和抗拉强度分别提高90％和130％。电铸铜的显微硬度和抗腐蚀性能均明显提高。 2．电铸层材料性能受电流密度、芯模速度等工艺参数的影响，提高芯模速度有助于提高电铸层的力学性能。 3．游离粒子磨擦通过有效降低电铸层孔隙率、细化晶粒及改变晶面的择优取向，来提高电铸层的材料性能。 （五）游离粒子磨擦提高电铸速度的机理研究 分析电铸传质过程，进行大电流磨擦辅助电铸镍试验研究，得出如下结论： 1．游离粒子贴近沉积层表面作复杂运动，直接作用于阴极与电铸液的交界面，能加速扩散层内的传质过程，有效减薄扩散层厚度，增大极限电流密度。在磨擦辅助电铸镍试验中采用的电流密度比常规电铸高一倍以上，电铸速度大幅度提高。 2．游离粒子磨擦能抑制沉积层表面突出点的优势生长，避免结瘤的产生与长大。这一作用有助于实现零件的一次性电铸成形，大大缩短电铸周期。 （六）研制磨擦辅助精密电铸机床，提出象形阳极筐技术 1．研制出一台磨擦辅助精密电铸机床。机床采用双立柱龙门Π型-C型复合结构布局，结合阴极运动机构和外置沉积单元的 设计 领导形象设计圆作业设计ao工艺污水处理厂设计附属工程施工组织设计清扫机器人结构设计 ，实现不同形状和尺寸零件的磨擦辅助精密电铸成形，并获得表面平整光亮、组织致密的高性能电铸零件。 2．提出象形阳极筐技术，建立有限元模型，对阳极轮廓进行优化设计，使电铸阴极表面电场分布的均匀性得到显著提高。 （七）开展磨擦辅助精密电铸技术的应用研究 结合液体火箭发动机和破甲弹的发展需求，将磨擦辅助精密电铸技术应用于其关键零件的制造。 1．成功制造出带冷却通道的火箭发动机推力室身部样件。所电铸的镍外壁厚度均匀、表面光亮平滑，实现了6mm大壁厚零件的一次性电铸成形，电铸周期大幅度缩短。 2．采用磨擦辅助精密电铸技术成功制造出破甲弹镍药型罩和铜药型罩。性能测试表明，所制造镍药型罩的破甲性能优于目前我国武器装备中的铜药型罩。静破甲试验表明，所制造铜药型罩的破甲性能优于旋压制成的同型号破甲弹。 本文的主要创新性研究如下： ​ 发现游离粒子磨擦能改善电沉积过程的现象，揭示了游离粒子磨擦影响析氢过程、电结晶过程和传质过程的机理。 ​ 首次实现电化学沉积配以机械微量磨削的复合电沉积技术，成功制备出高性能的纳米晶光亮镍沉积层。 ​ 发明磨擦辅助精密电铸技术，彻底解决了常规电铸中存在的针孔、麻点、结瘤和晶粒粗大等关键问题，提高了电铸层材料性能和电铸速度，缩短了生产周期。 ​ 研制出具有游离粒子磨擦辅助功能的高性能精密电铸机床，并提出象形阳极筐技术用于机床，来提高电铸阴极表面电场分布的均匀性。 ​ 首次实现大壁厚零件的一次性电铸成形，成功制造出火箭发动机推力室身部样件和聚能装药破甲弹的高性能药型罩。 上述研究内容已在中国科学E辑（英文版）、Materials Letters、International Journal of Advanced Manufacturing Technology等国内外权威期刊发表。一篇论文在2006年CIRP国际会议上宣读，得到国内外同行的关注和好评。已授权国家发明专利2项。本文研究成果作为项目“高性能精密微细电铸制造技术”的主要内容，获2007年国家技术发明奖二等奖（排名第四）、2006年国防科学技术奖一等奖（排名第四）和2009年教育部自然科学奖二等奖（排名第三）。相关技术与机床作为项目“高性能电铸技术与装备”的重要组成部分，获2008年中国国际工业博览会创新奖。 关键词： 精密电铸，游离粒子，微量磨削，摩擦，电铸机床，应用 Research and application of abrasive-assisted precision electroforming Zhu Zeng-Wei ABSTRACT Electroforming is a non-traditional machining technology of manufacturing components by electrodeposition, in which extremely minute metal ions are reduced on a pre-shaped cathode mandrel and the electroforming deposit is formed by electro-crystallization. It has many advantages, such as high fidelity of shape reproduction, high repetitive forming accuracy, controllable material property, etc. Electroforming is mainly used to fabricate the metallic parts that are too difficult or expensive to manufacture for traditional machining. In America, Germany and other industrial developed countries, electroforming has been highly valued and employed in the high-tech areas of aerospace, weapon，electronics and otherwise. In these areas electroforming has been used to manufacture some key components, for example, rocket nozzle, shaped charge liner, optical component, microwave guide, copper lining for RF cavities, mold and so on. To some parts with special requirements, as the outer wall of rocket engine thrust chamber, electroforming is the only feasible method of fabrication. However, view from the present research situation at home and abroad, there are still some disadvantages in conventional electroforming process that are difficult to overcome and seriously restrict the development of electroforming, such as pinholes, pits, nodules and other defects, coarse grain, long production cycle, and so forth. When bubbles of hydrogen gas produced in hydrogen evolution adhere to the cathode surface, electrodepositing is prevented, pinholes and pits results. Due to the predominant growth of micro projections, nodules usually appear on the deposit surface. As deposits grow progressively thicker, the nodules will be exaggerated. These severe defects will lead to the decrease of the material properties, the interruption of electroforming process and even waste products. Usually the properties of electroformed material can not meet the requirement of parts because of the micron-sized coarse grains, which is common to the conventional electroforming. For the existence of limiting current density, low current density and extremely long production cycle have to been employed to obtain acceptable deposits in the conventional electroforming process. So there are some difficult problems to resolve urgently, namely how to improve the deposit quality and property, increase the deposition rate and shorten the electroforming cycle. In this dissertation, a new electroforming technology, namely Abrasive-assisted Precision Electroforming (APEF), has been developed. In the new technology, non-conducting free abrasive particles are forced to polish the cathode surface while electrodepositing. The free particle polishing can help to improve the quality of deposits and increase the electroforming rate. The mechanism of APEF has been researched theoretically and experimentally. The research is focused on the effects of free particle polishing on the deposit’s surface, microstructure, properties and deposition rate. An APEF machine has been developed, and the applications of APEF have been researched. The main research contents in this dissertation include: 1. Research on the hydrogen removal action of free particle polishing Based on the analysis of hydrogen evolution and its effects on deposit, the hydrogen adsorption resistance of free particle polishing during electroforming was researched emphatically. Through nickel and copper electroforming experiments, the outer appearance and porosity of the deposits were studied. The results showed that the free particles could remove mechanically the adhered bubbles on cathode and reduce the volume of evolved hydrogen by decreasing the over-potential of hydrogen evolution. It was found in experiments that the particle polishing could eliminate the passive effect of hydrogen evolution and nickel deposits electroformed without pinholes and pits could be achieved by APEF. 2. Research on the level action of free particle polishing to deposit surface The motion and force characteristic of free particles during the APEF process were analyzed, the level mechanism of free particles to deposit surface was disclosed, and the surface roughness and micro-morphology of the nickel deposits electroformed with various processing parameters were studied. The theoretical analysis showed that the free particle polishing on the growing deposit could help to remove effectively the surface nodules and increase the surface smoothness and brightness by micro grinding. The APEF experiments achieved satisfied results: (1) The micro-morphology of deposits appeared obvious grinding traces. With the increase of cathode speed, the free particle action was reinforced and the traces became more notable. (2) For the nickel deposits, the surface was smooth and bright without any nodules, nearly mirror effect. The surface roughness was less than Ra 0.02 m. Speedup of cathode help to decrease the roughness. 3. Mechanism analysis and experimental research on the effects of free particle polishing on deposit microstructure improvement The influencing mechanism of free particle polishing on the deposit microstructure was studied by theory analysis and experiments. Following conclusions were achieved. The results of theory analysis showed that the free particle polishing to the surface of growing deposit could refine the grain by increasing the cathode over-potential, and change the structure of deposits by affecting the growth of crystallites. It was found in experiments that the microstructure of nickel and copper deposits produced by APEF significantly changed in contrast with the conventional electroforming technology. For the nickel deposit, each diffraction peak’ intensity reduced distinctly, the preferred orientation degree changed evidently, and the grains were substantially refined. Nanocrystalline nickel with grain size of less than 80nm was achieved. 4. Analysis of material properties of the deposits electroformed by APEF The material properties of the prepared deposits were measured and analyzed, the variation of the properties with processing parameters and the relationship between the properties and microstructure were studied. The results showed: (1) Comparing with the deposits produced by conventional electroforming technology, the deposits produced by APEF exhibited better properties. For the nickel deposit, microhardness increased 90% and tensile strength increased 130%. The copper deposit also represented higher microhardness and better corrosion resistance. (2) Deposit properties were affected by current density and cathode speed, and higher cathode speed was useful to enhance the mechanical properties. (3) The improvement of deposit property had relation to the decrease of porosity, the refinement of grain and the variation of each diffraction peak’ preferred orientation degree. 5. Research on the effect mechanism of free particle polishing on electroforming rate The mass transport process in APEF was analyzed and experiments of nickel electroforming with high current density were carried out. Following conclusions were achieved. (1) The free particles touching tightly the cathode surface moved with random directions, disturbed directly the interface between cathode and electroforming solution. The disturbance could substantially diminish the thickness of diffusion layer by accelerating the mass transport in diffusion layer, which led to the increase of the limiting current density. For nickel electroforming, the current density used in APEF was at least one time higher than that one in conventional process, and the electroforming rate increased significantly. (2) The free particle polishing could avoid the production and growth of nodules by suppressing the predominant growth of surface micro projections, which helped to realize the once-and-for-all electroforming of parts and largely shorten the production cycle. 6. Develop a precision APEF machine and present a fabrication method of optimized anode basket (1) A new precision electroforming machine was developed. A double vertical column Π style-C style hybrid structure was chosen as the main mechanical structure. A cathode movement device and a deposition unit were designed to guarantee the implement of APEF technology. (2) A unique anode basket was fabricated and its anode profile was optimized by using Finite Element Method. As a result, the uniformity of current density distribution on cathode surface was improved effectively. 7. Application research of APEF technology Based on the requirements for development of liquid propellant rocket engine and shaped charge warhead, the manufacturing technique of their key parts was researched. (1) A sample of rocket engine thrust chamber with cooling channels was successfully manufactured by APEF. Its nickel outer wall with thickness of 6mm was electroformed without interruption. The wall surface was smooth, mirror-like and the wall thickness presented excellent uniformity. The electroforming cycle was significantly shortened. (2) A nickel shaped charge liner and a copper one were electroformed by APEF. The results of performance tests showed that the nickel liner manufactured by APEF appeared more excellent penetration performance than the copper one in the weapons equipped for the military in our country. The results of penetration tests showed that the penetration performance of the copper liner manufactured by APEF was better than the one manufactured by spin forming. The key innovation researches in this dissertation was as followed: ​ A phenomenon that free particle polishing can improve the process of electrodeposition was discovered. The effects of free particle polishing on hydrogen evolution, electro-crystallization and mass transport process were disclosed. ​ A compounded electrodeposition technology with auxiliary micro grinding was implemented for the first time. By the technology a bright nanocrystalline nickel deposit with mirror-like surface and high properties was achieved successfully. ​ A technology of Abrasive-assisted Precision Electroforming (APEF) was invented. This technology resolved the puzzles such as pinholes, pits, nodules and coarse grain in conventional electroforming, increased the material properties and electroforming rate, shortened the production cycle. ​ A high performance precision electroforming machine with subsidiary function of free particle polishing was presented. For the machine, a fabrication method of optimized anode basket was presented to enhance the uniformity of electric field distribution on cathode surface. ​ Once-and-for-all electroforming without interruption of parts with heavy thickness was implemented for the first time. Sample parts of rocket engine thrust chamber and high performance shaped charge liners were successfully manufactured. The above works have been published in some authoritative periodicals at home and abroad, for example, Science in China Series E, Materials Letters, International Journal of Advanced Manufacturing Technology. One paper presented in 2006 CIRP Annals had caught the attention and favorable comments of the peers both domestic and abroad. Two Chinese patents authorized have been owned. As the main content of project “High Performance Precision and Micro Electroforming”, the research findings won 2nd Rank National Award for Technological Invention in 2007 (fourth place), 1st Rank Defense Award for Science and Technology in 2006 (fourth place), 2nd Rank Education Ministry Natural Scientific Award in 2009 (third place). As an important constituent part of project “High Performance Electroforming Technology and Equipment”, the related technology and machine were awarded the Creation Prize by China International Industry Fair in 2008. Key words: Precision electroforming, Free particle, Micro grinding, Polishing, Electroforming machine, Application