EMAG ECM GmbH (ECM/PECM) 精微電化學加工技術在未來各種細微加工應用中佔有極大的優勢。該技術之優點係在於其加工能力與材料硬度無關，且能加工出微細及形狀複雜之表面結構，經由該製程加工後之產品表面具有粗糙度佳、無殘留應力及無裂縫產生等優良特性，常應用於航太、光電半導體、醫療器材、綠色能源、模具等產業上，本次研討會中特別邀請國內外知名學者及專家，介紹於精微電化學領域內之各種加工技術，可應用於燃料電池雙極板、生物晶片、微流體動壓軸承、微噴嘴、次世次流體分配閥元件、模具等產品加工上，機會難得，精彩可期。PECM為精密電化學切削的工程公司，其領先的技術，已在精密電化學切削領域達到量產化的水準。供顧客PECM精密電化學切削生產技術和客制化的製程設備。
詳全文 元智大學機械系電化學精密加工.mpg-利豐非傳統加工科技館 www.li-fung.biz-新浪部落 http://blog.sina.com.tw/lifung/article.php?pbgid=24968&entryid=622135
詳全文 超精密拋光-利豐非傳統加工科技館 www.li-fung.biz-新浪部落 http://blog.sina.com.tw/lifung/article.php?pbgid=24968&entryid=622131
why uECM - micro electrochemical machining
Products are becoming smaller, lighter and more compact, and standards and quality requirements are rising. Micro-machining is finding more applications in many products in the aerospace, automotive, medical device, jewelery and consumables industries. There are many forms of micro-machining processes such, as laser machining, electro-discharge machining (EDM), micro-milling and electro-chemical machining (ECM) to name a few. In many instances the SME’s are the driving force behind advance in these technologies.
example of feature dimensions
The ECM process has many advantages as regards to other machining techniques. These can be divided in machine, material and product.
- Low running and tooling costs.
- Initial investment in tooling is high, but the recurring costs are low.
- o?electrode wear.
- The hardness, toughness and thermal resistance do not effect the Material Removal Rate (MRR). For tooling the product it is also not important if the tooling occurs before or after a hardening step.
- MRR is high, approximately 1,5 cm3/min at 1000 A DC.
- MRR does not depend on the type of material.
- Hard and tough alloys are equally quick machined as for instance Aluminium.
- The product is after tooling free from burrs.
- Contact free tooling principle.
- The process gets no thermal or physical tension in the product.
- No upper layer deformation like in other machining techniques.
- 3-Dimensional products can be tooled in one single step.
- High surface qualities are feasible (Ra <0,05 µm) depending on the material.
- High dimension accuracy is feasible.
- Material tension which is released during the process, is being counterbalanced if possible.
- Stainless steel is influenced in its upper layer by various machining techniques, by which local rust formation can occur. This does not happen with ECM.
- With the application of ECM, it is possible to generate more freedom of design for the product.
Electrochemical machining (ECM) is a method of removing metal by an electrochemical process. It is normally used for mass production and is used for working extremely hard materials or materials that are difficult to machine using conventional methods. Its use is limited to electrically conductive materials. ECM can cut small or odd-shaped angles, intricate contours or cavities in hard and exotic metals, such as titanium aluminides, Inconel, Waspaloy, and high nickel, cobalt, and rhenium alloys. Both external and internal geometries can be machined.
ECM is often characterized as "reverse electroplating," in that it removes material instead of adding it. It is similar in concept to electrical discharge machining (EDM) in that a high current is passed between an electrode and the part, through an electrolytic material removal process having a negatively charged electrode (cathode), a conductive fluid (electrolyte), and a conductive workpiece (anode); however, in ECM there is no tool wear. The ECM cutting tool is guided along the desired path close to the work but without touching the piece. Unlike EDM, however, no sparks are created. High metal removal rates are possible with ECM, with no thermal or mechanical stresses being transferred to the part, and mirror surface finishes can be achieved.
In the ECM process, a cathode (tool) is advanced into an anode (workpiece). The pressurized electrolyte is injected at a set temperature to the area being cut. The feed rate is the same as the rate of "liquefication" of the material. The gap between the tool and the workpiece varies within 80-800 micrometers (.003 in. and .030 in.) As electrons cross the gap, material from the workpiece is dissolved, as the tool forms the desired shape in the workpiece. The electrolytic fluid carries away the metal hydroxide formed in the process.
As far back as 1929, an experimental ECM process was developed by W.Gussef, although it was 1959 before a commercial process was established by the Anocut Engineering Company. B.R. and J.I. Lazarenko are also credited with proposing the use of electrolysis for metal removal.
Much research was done in the 1960s and 1970s, particularly in the gas turbine industry. The rise of EDM in the same period slowed ECM research in the west, although work continued behind the Iron Curtain. The original problems of poor dimensional accuracy and environmentally polluting waste have largely been overcome, although the process remains a niche technique.
The ECM process is most widely used to produce complicated shapes such as turbine blades with good surface finish in difficult to machine materials. It is also widely and effectively used as a deburring process.
In deburring, ECM removes metal projections left from the machining process, and so dulls sharp edges. This process is fast and often more convenient than the conventional methods of deburring by hand or nontraditional machining processes.