________________________________________________________________________________________________________________________
thin walls and high-aspect ratio microhole drilling ), superfinished surfaces , and advanced-material machining capability that manufacturers need to produce the next generation of advanced components for critical industries without compromising part materials or design concepts .
Manufacturers should carefully consider how and why non-conventional manufacturing processes work before making any further investment . PECM , for instance , removes material without the use of contact or heat , and works on a fundamentally different level than conventional processes . Processes like PECM can be best understood by observing its key components :
The Cathode , also called the electrode , is the custom-designed tool shaped as the inverse of the desired geometry on the workpiece . It is lowered onto the workpiece during machining , but never comes into contact with it - separated by a microscopic gap called the inter-electrode gap ( IEG ).
The Anode , or the workpiece , can be any conductive material , however PECM is most applicable on tough-to-machine metals commonly found in the aerospace and medical device industries , including nickel superalloys . PECM can technically be used on bar stock or raw plates but is more useful when machining near-net shape parts that are stamped , rough machined , etc .
The electrolytic fluid acts as both the catalyst for the electrochemical reaction to take place , as well as a flushing agent that removes both waste products and heat from the workpiece area . These two critical functions are performed simultaneously as the fluid is flushed into the IEG .
The power supply supplies the electrolytic fluid with the necessary current to conduct the electrochemical reaction ; this current is correlated with PECM ’ s material removal rate .
PECM works by breaking down the chemical bonds of the metal atoms on the workpiece surface into metal hydroxides .
These byproducts are created in the electrolytic fluid , which is then flushed away , leaving no heat-affected zones and a superfinished surface quality .
Note : this is only a summary of PECM technology - for a more in-depth analysis on how PECM removes materials atom-by-atom using an electrochemical reaction , click the link at the end of the piece .
As alternative machining methods have unique capabilities and advantages over conventional processes , so too do they have special impediments and disadvantages manufacturers should consider . With PECM , for instance , many of its most definitive traits can act as inherent limitations to the technology :
■ PECM ’ s lack of contact or heat allows stress-free machining on features otherwise sensitive to thermal distortion or tool vibration , such as thin walls . PECM is capable of producing < 0.075mm or < 0.003 ” thick walls with a 20:1 aspect ratio .
■ However , PECM is not cost-effective compared to conventional processes when tasked with machining simplistic geometries that may require a high
16