As companies are looking more into energy diversification, it has created a dynamic investment environment for alternative energy options. Photo chemical etching company Precision Micro has expressed its solution, particularly in the fuel cell industry.
Bipolar fuel cell plates are traditionally manufactured from graphite using CNC machines. Not only is the material expensive, but it is highly permeable, making it less than ideal for mass manufacturing applications. This has pushed other materials to be considered as alternatives—particularly stainless steel and titanium.
Fuel cells are created by stacking intricate plates with complex grooves or channels that allow liquid and gas to flow through. While the cells can be manufactured with CNC machines, hydroforming and stamping, there is still apprehension concerning the scalability and capability of these processes.
Stamping and hydroforming, both traditional metalworking technologies, tend to compromise planarity (flatness), which can cause stresses and burns. On the other hand, single-point machining processes and presswork tooling are slow and can be uneconomical to produce, especially when they must undergo research and development.
This is why Precision Micro has been actively promoting the use of the photo chemical etching process. Photo etching does not require hard tooling. Instead, it uses digital tooling, which allows designs to be optimized inexpensively.
The photo chemical etching process involves removing metal simultaneously, which means that complex channels or flow fields can be etched to 0.025mm on both sides of a plate. According to Precision Micro, the versatility of this process—which enables designers to work easily with various sizes and shapes of channels and incorporate headers, collectors and port features with very little additional cost—has not been possible with other alternative technologies.
Additionally, the process allows users to quickly go from prototype volumes to high volume manufacturing—all while still offering almost unlimited part complexity plus burr- and stress-free components. The process also doesn’t affect metal temper and properties and is appropriate for all grades of steel.
Precision Micro typically manufactures bipolar plates from 316- to 904-grade stainless steels in plate sizes to 1500mm x 600mm. However, plates can still be specified in metals that are usually hard to machine—like titanium—for lighter-weight and corrosion resistance in high-temperature fuel cell applications.
The company encourages fuel cell engineers to consider photo chemical technology as an innovative and efficient approach to the manufacturing process. According to Precision Micro, it is the versatility of the process that will make it a compelling option for manufacturers of complex sheet metal parts innumerous exacting applications. They also add that photo etching will open up innovative stimulation by making it easier and more efficient for design engineers.
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