3D printing, despite still being a relatively new technique, has the potential to change manufacturing as we know it. No matter what type of industry you work in, understanding the ramifications of this budding technology should be considered essential. Although new printers and new methods are being developed at a rapid pace, making it difficult to keep track of the changes, those manufacturers who can stay on top of the maturation of 3D printing will be at an advantage.
What is 3D printing?
There’s no one answer to the question of how to define 3D printing. Broadly speaking, 3D printing comprises a number of different processes that involve a material being solidified under computer control in such a way that it results in a three-dimensional object being formed. Typically, the process will include the material, such as liquid molecules or powder grains, being fused together. Common applications that involve 3D printing include rapid prototyping and additive manufacturing.
The finished objects that are printed can be of a wide variety of shapes since they are being created from digital data in the form of a 3D model. The major difference between 3D printing and traditional machining is that in the latter, material is taken away from some block of larger material, while with the former, the material is added together in layers until the desired shape is achieved. Some of the major technology categories that have been developed are stereolithography and fused deposit modeling. But in general, 3D printing is referred to as additive manufacturing, because the material is being added rather than being taken away.
What materials can be used for 3D printing?
While metal is a major material for the 3D printing industry, the range of materials in use is nearly as varied as the imagination of the researchers developing applications. Some of the most interesting include carbon fiber, plastic, paper, concrete, yarn, and food. But currently, the two materials that are by far the most interesting to manufacturers are plastic and metal.
The most familiar methods for 3D printing metal involve the use of high-intensity lasers. Two of the most common are selective laser melting (SLM) or direct metal laser sintering (DMLS). These techniques employ a high power-density laser that actually melts metallic powders and then fuses the melted powder together in the desired shape.
One of the many benefits of DMLS is that it can be partnered with a variety of metal alloys, meaning that it can be used to manufacture durable metal prototypes from the same material as traditional production components. Using the layer-by-layer additive process described above, the diversity of finished shapes and geometries is nearly endless, including the design of internal features and complicated passages that could not be cast or machined by any other means.
The digital file will divide the part to be produced into layers that vary from 20 to 100 micrometers in thickness, resulting in a series of 2D images for each layer. The data is stored in a standard file format known as .stl, which is recognized by most layer-based 3D printing and stereolithography technologies.
Next, thin layers of fine metal powder are evenly distributed via a mechanism that coats the material onto a substrate plate. Each 2D slice is then fused together by using a high-power laser beam to melt the powder, generally a ytterbium fiber laser. Two high-frequency scanning mirrors are used to direct the beam along the x- and y-axis so as to finely control which material is melted and welded together. The laser is so powerful that it fully forms the layers into solid metal.
What metals are best suited for 3D printing?
In theory, any metal that can exist in atomized (powder) form can be used for 3D printing. In practice, materials that are already in wide use and have been thoroughly tested make the most sense. Metals that are commonly found in 3D printing applications include aluminum, stainless steel, copper, cobalt chrome, titanium, tungsten, and gold.
Among these, high-strength aluminum alloys stand out as exceptionally popular. This is because of the many benefits that aluminum provides to manufacturers. Included among these alloys are the extremely prevalent 7075 and 6061 aluminum. What’s so revolutionary about this is that even though these alloys have always been highly desired in the aerospace and automobile industries, they have also been extremely difficult to weld, limiting their usefulness. 3D printing advances has made it possible for these common alloys, as well as other extremely high strength nickel-based alloys, to be employed in ways that have never been possible before.
Through the use of zirconium-based nanoparticles, researched have solved many of the limiting factors that have inhibited manufacturers in the past, including hot cracking. Essentially, the technique has transformed unweldable metals into weldable ones, all with the simple application of a nano-coating. The technique is already leading to amazing breakthroughs, such as allowing for lighter aircraft than previously possible.
Other applications in the aerospace industry include air ducts, fixtures and mountings for both commercial and military aircraft. In the medical field, 3D printing is making it possible to prototype complex medical parts much more cheaply, allowing for faster and less expensive research into new devices. Tooling is another area being transformed by 3D printing, eliminating tool-path generation and multiple machining processes such as EDM. Tool inserts can now be built in just a few hours.
Your Technical Resource Partner
3D printing is still a relatively new technology. Manufacturers would be well advised to consult with knowledgeable partners who understand the complexities involved. At Clinton Aluminum, we proudly serve as more than metal providers. We strive to be true partners who will leverage our extensive experience to make sure that our customers are successful at every step of the production process.
As the Midwest’s number one supplier of aluminum, Clinton Aluminum makes it our top priority to maximize the competitiveness of our clients. Contact us today to speak with one of our knowledgeable and friendly representatives.