Photochemical Machining

In this age of technological advancements, manufacturers are now placing greater emphasis on the precision and accuracy of materials to mass-produce consistent and high-quality products. Photochemical machining, or photochemical etching, is the pioneering process of manufacturing precision thin metal parts and specialized designs with exceptional accuracy.

This is a ground-breaking innovation in aerospace, electronics and medicine. The automated and digital nature of photochemical machining eliminates any possibility of variability or derangement associated with manual production. There is more to photochemical machining than its superior design quality and efficiency, so continue reading to learn about PCM, its process, its advantages over traditional methods and its applications in industries.

What Is Photochemical Etching?

Photochemical etching is a versatile, reductive process involving the use of chemical etchants to cut metal sheets with a high degree of precision selectively. The sophistication of products you can manufacture with the combination of photographic and chemical techniques in PCM is impossible to achieve by traditional methods. Once the design is complete, you use a photoresist imaging to select the areas you want to save and the rest is corroded away by pouring a robust chemical solution over the piece to achieve an intricate design.

Processing

Despite its intricacy, PCM is a fast and economical multistep process. You must choose a suitable metal alloy that can corrode readily. For example, stainless steel, copper, aluminum and titanium are common alloys used for photochemical etching. 

In the first step, you prepare the metal by cutting it into sheets and cleaning them using chemical reagents and mechanical brushing to avoid contamination during subsequent steps. The general steps in the process are as follows:

1. Photo Tooling

This step requires you to use CAD (Computer-aided design) software to convert the design into a digital drawing, which you can then transfer to a transparent mylar film or a photo tool.

2. Lamination

Then, you press each metal sheet between two layers of a dry photoresist film and apply pressure and heat to adhere the photoresist uniformly to the surface of the metal. 

3. Exposure

Next,  you print the photo tool onto the laminated surface. When you expose the sheet to UV radiation, the areas of photoresist covered by the photo tool will remain unaffected, and the rest of the surface hardens through a polymerization reaction. These hardened areas will resist etching action in the next step while you dissolve the photo tool design.

4. Developing

In this step, you wash the laminated sheets with a mild alkali to remove the soft areas of the photoresist protected by the photo tool leaving behind the hardened surface.

5. Etching

Lastly, you roll the metal sheet through a conveyor belt into an etching machine, where the etchant is sprayed. A redox reaction occurs, and the exposed metal surface is cut away. Next, you strip away the photoresist from the metal, carefully inspect the etching and then package it appropriately. 

Applications and Advantages

PCM is commonly used in the aerospace industry for parts like fuel nozzles, heat exchangers and engine blades. You can also use it to produce printed circuit boards for electronic devices and micro-components of micro-electro-chemical systems and surgical and implantation instruments. 

You can use PCM to generate renewable energy by efficiently creating parts like cathodes and electrolyzer plates. It is also widely used in the automotive industry due to advantages like high precision and tight tolerance in fabricating intricate and complex geometries. 

Using PCM, you can mass produce with consistent and accurate results. It also enables you to use various metals for your products. Additionally, the process is highly affordable, energy-efficient and stress-free.

Endnote

PCM is a precise and affordable manufacturing process of metal cutting that delivers products with rapid turnaround times, minimal errors and reduced set-up costs. You can use it in various industries, opening new opportunities in the developing world of technology and advancement.