Chemical etching has several benefits over other traditional sheet metal working processes, making it the preferred option for many design operations. Its applicability to a wide range of metals and alloys, even ones that are difficult to machine, makes design engineers prefer it over conventional sheet metalworking processes.
Virtually, you can chemically etch any material. However, as with more metal matching processes, you find that some metals are easier to etch than others.
In this post, we will share with you some of the typical metals and alloys suitable for chemical etching.
What is Chemical Etching?
This is a high-precision process used by design engineers to produce complex components and parts out of sheet metal. During the chemical etching process, the machines apply the artwork on both sides of the material being etched to cut all the way through the sheet metal.
The process is a versatile and highly precise manufacturing technique that aims to retain the material’s hardness, magnetic permeability, temper, and other qualities without excessively stressing the material. It is also worth noting that tooling costs are relatively low. You can easily incorporate design changes during the process without causing excessive stress to the metal.
As demand from metal artwork industries focuses more on metals with attractive attributes, we will focus our efforts on materials that ensure the process is developed in line with the consumers’ market demands.
As an alternative to “conventional” etching methods like lasers, water jets, or stamping of wire EDM, chemical etching provides a more accurate and economical solution for more precision metal applications.
With that said, here are some of the top metals that are suitable for chemical etching:
Etching Titanium and Its Alloys
Unlike most metals, titanium is very lightweight, strong, and is highly resistant to fatigue and aggressive environments. While these properties make titanium a suitable metal for etching, they can prove challenging when machining.
For instance, titanium’s high strength, chemical reactivity with conventional tool materials (at high temperatures), and low thermal conductivity can reduce tool life significantly when machining.
Additionally, long continuous chips are produced during the turning and drilling process. These can easily entangle with the cutting tool and become an issue, especially when using automated machining.
Using chemical etching on titanium can help overcome most of these issues. However, the metal can form a protective oxide coating almost immediately it is exposed to air, making it almost impossible to etch using standard etch chemistries.
Etching companies can overcome titanium’s oxidation by using specialist equipment and process chemistry (mainly hydrochloric acid) to produce etched parts and components comparable in quality to those etched from most metals.
Aluminum Etching
Aluminum also exhibits most of titanium’s attributes – mainly the high strength to weight ratio. Its natural corrosion resistance is also somewhat similar to titanium. However, titanium is much stronger and more corrosion-resistant. On the other hand, aluminum has a better fatigue limit, making it a more suitable metal for aerospace applications.
Also, like titanium, several issues may arise when chemically etching aluminum that ends up compromising the quality of cut, including the coating of the presswork and heat reflectivity.
Additionally, most suppliers find aluminum to be more difficult to etch effectively because of the heat energy it releases during the process. This usually results in a rough and granular edge. That’s why many suppliers use other proprietary methods for etching aluminum to ensure the best edge quality comparable to that of stainless steel.
Steel and Stainless-Steel Etching
While stainless steel is less difficult to etch, you still need significant investment and application of experience when using processing technologies to optimize your customer outcomes and expectations, especially in volume manufacture.
To etch stainless steel, you will need a stainless-steel sheet that has been laminated with a photoresist mask. The stainless-steel sheet will then be etched selectively with ferric chloride. It is a safe-to-use and etchant chemistry process that guarantees better and more precise edges.
Due to its range of available grades and versatility, you can use stainless steel for a variety of applications. It is particularly great for applications that benefit from burr and other stress-free features. You also won’t have to deal with exorbitant costs due to the component’s complexity.
Etching Nickel and Nickel Alloy
Like most metals, nickel also exhibits high resistance to corrosion and heat, though again, etching this metal is relatively straightforward using standard etch chemistries.
Its soldering capabilities make nickel silver the preferred metal component for electronics shielding. It does not oxidize or require additional plating. As such, its chemical etching process is relatively simple and less costly.
Etching Copper and Copper Alloy
As a relatively soft material, copper also etches quickly when standard etch chemistries are used. However, it is also worth noting that contact matching processes can distort it, altering its properties and etching precision.
Copper and its alloys are also highly conductive, ductile, malleable, and durable, making them the preferred metal for 2-D and 3-D electronics components.
Inconel
Inconel is a nickel-based super-alloy with superior heat resistance. It exhibits excellent resistance to pressure, oxidation, and corrosion. These properties make Inconel even more difficult to machine.
Its high temperature and corrosion resistance properties make it the best-suited material for oil and gas extraction industries. Inconel can withstand extreme environments alongside volatile and corrosive gases. Its alloy properties also make it resistant to carburizing, cracking, and pitting.
Like titanium, Inconel forms a thick and stable oxide layer almost immediately to protect its surface from attack when heated. As such, it can be difficult to etch and shape using conventional machine etching processes.
Why Choose Advanced Metal Etching as Your Chemical Etching Supplier?
Etching any metal successfully falls down to the skills and experiences of your preferred chemical etching partner. American Metal Etching has over 30 years of metal etching experience, making us an industry leader in the country.
Continual investment in the chemical etching industry and process parameters allows us to etch even the most challenging metals in volume. We pride ourselves on exacting chemical etching standards in terms of accuracy and tolerance.