The ability to create objects on demand from virtually anywhere has long been a dream of engineers and manufacturing professionals. Traditionally, fabrication has required lots of equipment, large factories and a workforce skilled in the use of machinery needed to manufacture objects. All of this changed, however, in the early 2010s as 3D printing hit the mainstream.
As a concept, 3D printing, sometimes referred to as additive manufacturing, has been around since 1945. Through the various iterations of this technology, the additive manufacturing industry has used a variety of materials, most of which have been polymers. One of the biggest goals of 3D printing, however, has been to print objects using metal.
The History Of 3D Printed Metal
Metal additive manufacturing was introduced to the world in 1971 when Johannes Gottwald created the Liquid Metal Recorder. This technology served as a precursor to modern 3D printing by implementing the same additive concepts used today. The Liquid Metal Recorder was based on earlier concepts like inkjet printing in which a computer is used to transfer information to a printer that places droplets of ink in precise locations on a piece of paper.
The Liquid Metal Recorder created droplets using liquid metal that were then built up using layers. This version of metal 3D printing was innovative in its time, but it lacked the precision and refinement capabilities that mark today’s 3D printing capabilities.
In 1982, defense research and technology firm Raytheon created a method for 3D printing metals using metal powder. This method is still used today for 3D printing metal parts and other metal objects by using fine powders made of metal particles and other additives. Modern metal 3D printing often introduces the use of lasers into the process along with alloys like aluminum, titanium, stainless steel, copper, silver and gold.
How Does 3D Printing In Metal Work?
Metal 3D printing is accomplished by making alloys into a pliable state. While polymers have more plasticity and are therefore easier to shape and mold, metals have always been a challenge in additive manufacturing. Metal in liquid form provides much more flexibility for injecting into 3D printing devices, but the amount of liquidity needed to make metals usable can also affect their ability to hold a shape once expressed onto a medium.
When metal powder is used in 3D printing, it is usually heated using either a plasma torch or a similar source of heat or it is melted in a furnace. Additional particles may be mixed in during the heating process depending on the end product being created. The metal will need to be at the correct temperature as too much heating will cause the metal to become unworkable, as mentioned above, but too little heat will cause the metal to lose plasticity or become too brittle.
Metal 3D printing requires the use of a printing device that dispenses the liquefied metal, but in order to do so in an orderly fashion, computer-aided design (CAD) is typically used. This software can be used to create the precise designs that a 3D printer follows, and engineers and designers use CAD software to create instructions for how a 3D-printed object will look, including its dimensions and density.
Most 3D printers that work with metal also include their own software applications and onboard settings. These can be used to customize controls, both internal and external, as well as input the various types of materials that a printer is working with. Different materials may require different tools or tips to be attached to printer heads or nozzles, and the speed with which materials are expressed will vary based on the design, the metal and the purpose.
Manufacturing And Rapid Prototyping Metal Components
One of the biggest advantages of metal 3D printing is that these technologies can be used for rapid prototyping as well as finished goods manufacturing. Prototyping is a process during which ideas are put into physical form to see how they operate outside of conceptualization. In the past, creating prototypes for complex objects was a costly and time-consuming endeavor that could take weeks, months or even longer to achieve.
Through the use of 3D metal printing, prototypes can be created within days or even hours using a variety of alloys. Another benefit of rapid prototyping is that multiple different prototypes can be created quickly using alterations of a single design.
This can give manufacturers and engineers a chance to see and feel the operation of a component before sending it to a factory floor for mass production. Rapid prototyping also opens the door for opportunities in custom and one-off production using customer files that have been uploaded via the Internet.