We have been getting a lot of questions recently about additive manufacturing. It’s no wonder, as additive manufacturing has become the latest buzzword to sweep the industry. More commonly referred to as 3D Printing, this quickly advancing technology is transforming the way things get made and has the potential to completely revolutionize manufacturing.
While many people think of 3D manufacturing as a way to create plastic objects cheaply, quickly, and repeatedly, many other materials are being experimented with as well. This includes metals such as aluminum. While designers and engineers have been working with high-performance alloys such as titanium and nickel for years, there is an increasing focus on the possible uses of aluminum alloys in additive manufacturing applications.
Today we’ll be discussing how aluminum is currently being used in 3D printing and what the future might hold.
What is additive manufacturing?
The term “3D printing” refers to a number of processes that involve material being joined or solidified to form a three-dimensional object under the direction of a computer. Because the material gets added together in a layer-by-layer procedure, it is also known as additive manufacturing. This is in contrast to traditional methods of manufacturing in which material is removed from an object, in what is known as subtractive manufacturing, or poured into a mold.
While the technique has been around since at least the 90’s, recent advances in precision, repeatability, and material options have made 3D printing commercially feasible as an industrial-production technology. One of the main advantages is the ability to create very complex shapes. And because parts are produced based on digital 3D models or CAD files, every outputted item is nearly identical. Costs continue to come down as well, making it even more viable.
How does 3D printing work with metal materials?
The type of 3D printing that most people are familiar with right now involves using plastic polymers, because of the cheapness and ease of use of these materials. However, metal additive manufacturing is quickly becoming popular.
The process normally (though not exclusively) relies on the use of metal powders that are fed into the 3D printers and then molded together through various techniques, such as with lasers or a heated nozzle. Other forms of metal that are already in use include wire, sheet, or liquid.
Currently, there are three metal additive processes that are commercially available at a large scale. The first of these relies on a laser-based machine, in which the metal powder is melted and fused with a laser electron beam. The different types of machines include direct metal laser sintering, selective laser melting, and electron beam melting. The next method is known as metal jetting technology. These machines solidify a photosensitive molding powder in a layer-by-layer process. The third category works with furnace-infused alloys, and relies on joining metal powder particles with a liquid binding agent.
These machines tend to be very expensive, and represent a huge investment, but have the potential to pay off relatively quickly. Whereas in the past these techniques were used only with prototypes, more and more industries are producing finished metal parts with additive manufacturing. 3D printing offers a very clear competitive advantage over traditional manufacturing methods.
How is aluminum being used in additive manufacturing?
The use of aluminum in 3D printing applications is projected to increase by 30-fold over the next decade. That’s an amazing growth curve, and every manufacturer, especially those already working with aluminum, needs to take notice.
In the early days of additive manufacturing, engineers found it very challenging to work with aluminum, because of its peculiar attributes. But this has lead to two separate developments with regards to aluminum. One, new high-performance aluminum alloys have been created specifically to take advantage of AM processes. Second, aluminum solutions have been developed specifically for die-cast applications. These two avenues have been leading the way for the popularization of aluminum in 3D printing applications.
The aluminum powders that are commonly in use today are most likely hypereutectic casting alloy compositions. They consist of extremely small powder particles that are spherical in shape. The sizes of the particles range from 10 to 75 micrometers (one thousandth of a millimeter). It’s important to note that for additive manufacturing processes, the particles need to be as close to spherical as possible to maintain proper flow during the process and ensure adequate mechanical properties in the finished parts.
Not all aluminum additive manufacturing relies on powder as its primary material. Aluminum wire is also popular, and actually can be used with a greater variety of alloys. The wire is formed into the finished part via an electron beam gun that deposits the aluminum layer by layer from the wire feedstock. This is the fastest of the currently viable methods and the size of the finished part is limited only by the size of the vacuum chamber.
A more recent development in additive manufacturing is giving us a preview of what the future of aluminum 3D printing might look like. This method is known as nanofunctionalization, and it is being tested on popular alloys such as 6061 and 7075. Nanofunctionalized aluminum powder is fed into the machine, and then heated with lasers until the desired shape is formed. One of the major advantages of this technique is the fact that the finished structures retain their alloy strength without cracking, owing to the nanoparticles acting as nucleation sites.
Aluminum 3D printing is already commonly found in a number of key industries, such as for aerospace, defense, and medical applications. Larger companies that are able to make the investment can purchase the large printing machines themselves, while smaller businesses can turn to third party companies that provide 3D printing solutions.
Your Technical Services Partner
3D printing is no longer just about plastics. Aluminum is quickly becoming a viable option for additive manufacturing and the growth of this industry over the next few years will be tremendous. That’s why finding a material supplier who understands the latest techniques and technologies is essential.
At Clinton Aluminum, our friendly and knowledgeable staff pride themselves on their ability to support our customers through every step of their production process. Contact us today to learn more about 3D aluminum printing and find out what aluminum alloy might be right for you.