Metal 3D Printing Methods, Applications, Pros And Cons
When we look at the growing number of industrial and commercial applications of additive manufacturing, 3D metal printing springs to the top of the list. It is among the fastest-growing manufacturing technology that has also seen a significant amount of investment. It can now be used in conjunction with other production technologies as well as to manufacture unique prototypes and manufactured goods. In some cases, the quality and efficiency of 3D printed metal objects can be just like the machined parts. 3D printing in metal has been used in prototyping, aerospace, engineering, specific tools, etc. In this article, we will go through some of the different aspects, including key technologies, their advantages, and limitations.
HOW DOES 3D PRINTING IN METAL WORK?
3D metal printing is a broad term for a family of several technologies. Simply put, any manufacturing technology that can create a metal object layer by layer by sintering, welding, or melting can be called 3D metal printing. This definition is not complete but let us skip the unnecessary technical details and take a look at the main benefits and drawbacks of 3D printing in metal.
ADVANTAGES OF 3D PRINTING IN METAL
People mostly think that CNC machining can be used for most tasks. However, in reality, there are certain limitations. Especially when you need to create complex parts, they could require the manufacture of new tools. This is a significant advantage of 3D metal printing, which does not have any limitations when it comes to the creation of objects with intricate designs. Other benefits of 3D metal printing include:
- 3D printers can produce intricate details more quickly than traditional manufacturing methods.
- They are less expensive than traditional manufacturing methods.
- Depending on the technology chosen, highly complex objects can be precisely produced.
- Details can be printed in 3D during assembly, saving time and money.
- Even with more complex designs, parts can be made lighter without compromising the strength. This is one of the reasons why 3D printed components are highly sought after in the aerospace industry.
- 3D printing in metal does not produce material waste, unlike the traditional production approaches.
- In short, it is the ideal approach for the creation of complex parts that are ineffective or difficult to produce with other technologies.
LIMITATIONS OF 3D METAL PRINTING
3D printing also has a few disadvantages as well. It is not feasible to produce regular parts on a large scale as traditional manufacturing methods. Therefore, mass production is not yet a viable option; other limitations of 3D metal printing are as follows:
- Metallic powders are costly compared to regular metal raw materials.
- 3D metal printing takes relatively longer to produce ordinary objects as compared to other approaches.
- 3D metallic printers are usually expensive.
- Post-processing such as surface treatment may be required.
- Precision and accuracy are generally lower as compared to CNC machining.
- Further heat treatment may be needed to lessen the internal stress of printed objects.
- The design used for 3D metal printing can be more complicated than other manufacturing processes. Therefore, experienced professionals who understand all the technical nuances of the process are recommended.
- It is not possible to produce large-sized parts.
The limitations are apparent when comparing common 3D printed metal parts with those produced by CNC machining or other conventional manufacturing techniques. Other than that, metal additive manufacturing has unparalleled advantages.
MAJOR 3D PRINTING TECHNOLOGIES
When it comes to 3D printing in metal, there are three major technologies. These are DMLS (Direct Metal Sintering Laser Sintering), LMS (Laser Metal Sintering), and EBM (Electron Beam Melting).
DMLS 3D PRINTING
Direct metal laser sintering or DMLS is the most common 3D printing method for metal. A laser is used to sinter the metallic powder layer by layer to form an object. During the course of this process, stainless steel can reach temperatures of up to 3000°F, but the metal does not melt. Available materials include a wide array of metal alloys, such as maraging steel, aluminum AlSi10Mg, Inconel 625, cobalt chromium, and titanium Ti6Al4V.
This method is used for creating prototypes and machine parts. It can be used to produce components with undercuts, cavities, and draft angles. These include medical devices, instruments, prototypes, and functional tools.
SLM 3D PRINTING
Selective laser melting or SLM, as the title implies, melts the printing material. 3D printing takes place in an inert gas environment. For this reason, the parameters of 3D printing are very similar to those manufactured with casting.
Objects made with SLM 3D printing technology are incredibly durable, which can be used to manufacture mechanical parts like propellers and gears. The automotive, medical, and aerospace manufacturers often use SLM to produce parts.
EBM 3D PRINTING
Electron beam melting or EBM is like SLM but uses an electron beam as opposed to a laser. This technology is faster and more accurate than laser-assisted printing, but there is not any significant difference. The created objects are generally more robust than other printing processes.
This method is primarily used to produce titanium and cobalt objects. This includes parts and components for aircraft, space shuttles, rockets, engines, etc.
3D printing on metal still has certain limitations. Metal parts produced by 3D printing processes such as DMLS, SLM, and EBM are deemed to be nearly as strong as the regular ones. However, many aspects limit the use of 3D metal printing. Therefore, it should be used to create items that cannot be effectively produced by traditional approaches. Furthermore, the metal 3D printers’ prices and the printing material are relatively high compared to the regular 3D printers. Metal 3D printing has a long way to go before it could become more accessible to everyday users.