Interesting Facts about Metal 3D Printing

Metal 3D printing is the crowning glory of additive manufacturing. The technologies based on metal laser sintering combine the flexibility offered by 3D printing in design and the unique mechanical characteristics of a vast array of metals. These are used to produce components and end parts that are incomparable in their strength and durability. 

A metal 3D print is obtained by melting 20-60-micron layers of metal powder, layer by layer, using a laser beam. This advanced technology is utilized to manufacture just about anything, including tooling inserts, production tools such as moulds, ducts, spare parts, and so on. These are especially in high demand in the aerospace and automobile industries for their lightweight features.

A Bit of History

The first ever patent filed for metal 3D printing was that by a German 3D print service in the 1990s, for direct metal laser sintering (DMLS). Metal 3D engineering has come a long way since them with innovations in printing methods for metals. Some of these techniques are vastly different from the original DMLS, while some carry variations of their own that warrant a patent.

How Does Metal 3D Printing Work?

As already stated, metal 3D printing uses a laser beam to melt powdered metals. This high-powered laser goes about selectively binding together particles on the powder bed while, simultaneously, even layers of metallic powder are distributed by the machine. The support structures,formed in the same material, are manually removed before the completed print is thermally treated.

Various Additive Technologies Can 3D Print Metals

Users are spoiled for choices when to comes to 3D printing technologies for manufacturing metal parts. 

Selective Laser Melting (SLM): Primarily used to metal alloys, SLM sinters the material, one layer at a time, as per the 3D model. The metal powder is completely melted in the process, owing to the presence of an inert gas (argon or nitrogen). Supports are required for this technology so that small angles and hangovers can be reinforced.SLM requires higher temperatures in order to melt the material completely, thereby its cooling period is also longer. It allows for the creation of detailed parts, sometimes even multiple components, making it suitable for the manufacture of industrial-grade propellers or gears.

Direct Metal Laser Sintering (DMLS): Like SLM, DMLS also works by sintering the metal powder on the basis of the shape of a 3D model. However, unlike SLM, DMLS does not involve the complete melting of the powder. As a result, DMLS 3D printing does not require as high a temperature as SLM printing, thereby shortening the cooling time as well. DMLS is extremely advantageous when to comes printing multiple components into a singular object or to produce thin-walled objects with detailed designs. DMLS 3D printed parts are ideally suited for use in the automotive or aerospace industries.

Binder Jetting: As the name suggests, this technology creates parts with the help of a binding agent, usually in a liquid form. Using a 3D CAD model, this method also creates the object layer by layer. Once printing is complete, the part is consolidated through hot isotactic pressing in order to avoid porosity and to also add the complete mechanical properties of the material.Binder jetting offers the option of plating, making it especially useful for 3D printingjewellery and decorative items.

Lost-wax Casting: In this technique,a 3D printed master model, in wax, is first obtained. Then, a plaster mould is poured over the wax model. Following the preparation of the plaster mould, liquid metal is injected to create the end product, while the wax is replaced in the process. The precision of this method makes it ideal for manufacturing jewellery, but not so for technical components.

Metals That Are 3D Printed

A wide range of metals and metal alloys are available for 3D printing. They vary in their mechanical properties, therefore, offering a range of industrial applications, including aerospace, defence, automobile, medical, and so on. The most popular metals used in additive manufacturing processes include:

1.    Stainless Steel420
2.    Stainless Steel316L
3.    MS1 Steel
4.    Aluminium (AlSi10Mg)
5.    Titanium
6.    NickelAlloy IN625
7.    NickelAlloy IN718
8.    CobaltChrome
9.    Matt Black Gold Nickel Steel
10.    Brass
11.    Bronze
12.    Copper
13.    Silver
14.    Platinum
15.    Gold 14k
16.    Gold 18k

Many precious metals, such as gold, platinum, and silver are also used to create jewellery and home décor, personalized items. Metals come with high tensile strength that may be difficult to process and print using conventional printing technologies. Moreover, metal 3D printing also helps reduce manufacturing costs and time.

Benefits of Metal 3D Printing

- Design Flexibility: Like any other form of 3D printing, metal 3D print techniques also offer a level of flexibility for designers, especially complex designs.In a relatively shorter period of time, design engineers have the option to explore more with no untoward effect on the product development cycle.

- Mass Customizations: Metals can be 3D printed to manufacture custom-made objects, making it one of the most cost-effective processes.

- Short Production Runs: As pointed out earlier, 3D prints in metal is cost-effective, especially for customized products. Therefore, depending on demand, short production runs can be undertaken without any additional costs.

Applications of Metal 3D Prints

Owing to the fact that metals offer their own characteristics that are advantageous with regards to plastics, parts created using metal 3D printing are extremely resistant, making them ideal in such sectors as automotive, aerospace or aeronautics that require precision and specific characteristic features in the materials used.

Not only functional prototypes, the applications of additive metal printing are beneficial to other areas as well, such as jewellery making. Parts with complex geometries likelightweight brackets and fixtures can be created in an inexpensive manner. These parts require high strength and stiffness, both features easily available with a variety of metals.