3D-printer for metal. Manufacture of metal products

3D printing is considered the most complex technological achievement and an important direction of additive production. Thanks to three-dimensional printers, new opportunities are opening up in all sectors of the economy. There is an opinion that in the future they can even displace traditional production methods (forging, casting, etc.). In this article we will consider what is 3D printing with metals and its main technologies.

What is a 3D printer for metal

These are special machines that allow you to make metal objects or apply coating to finished products. Such a printer "grows" a physical object layer by layer. That is, first a virtual model in three dimensions, divided into digital layers, is created on the computer in the design system. After starting the object in print, the 3D printer's head starts to squeeze out the liquid metal or pour the powder onto the printing platform, forming the first layer. Then the machine applies a second portion of metal and so on.

3D-printer for metal allows you to create a large range of products and, thanks to modern technology, can compete with classical methods of metal production.

What can I print with a 3D printer?

This printer is a universal invention, which can be used by both professionals and simple enthusiasts. Metal printers can be used for manufacturing non-standard objects, mechanical parts, jewelry. They also allow the creation of metal products simulating hand forging. And for this, no additional devices and mechanisms are needed.

An industrial 3D-printer for metal can even print a rocket engine. In this case, it will not practically differ from the product manufactured by the traditional method. Thus, the metal printer enables a modern person to create any objects.

3D printing technologies for metal

To date, the manufacture of metal products is carried out by two technologies: laser and inkjet printing. They mean a gradual and accurate layering of metal, as a result of which the intended figure should be obtained. At the same time, engineers have developed several ways to grow.

Inkjet 3D printing

The manufacture of metal products by inkjet printing is one of the oldest ways of additive production. It allows the best way to use metals as consumables. But this technology is applicable only in the case of creating a composite model. The matter is that the jet 3D-printer allows to print objects from any material, which can be processed into a powder. During printing, the ground raw materials are bound by polymers. Because of this technological feature, finished products can not be considered completely metal.

In addition, it is possible to convert the resulting composite models into all-metal ones. For this, thermal smelting or burning of polymers and sintering of powdered metal are used. Such metal products are not durable, since they have a porous structure. Add strength can be due to the impregnation of another metal. For example, a steel object will become more durable if it is impregnated with bronze.

This method of creating products is mainly used in the souvenir and jewelry industry.

Laminating method

3D printing by lamination means the application of thin sheets of metal formed by laser or mechanical cutting to the platform and their gluing to obtain a three-dimensional model. This method allows us to use even metal foil as an expendable material. Laminated objects do not have metallic strength, since their integrity is based on the bonding of bonded sheets.

The advantage of this technology is relative cheapness and the ability to create a variety of items that are identical with all-metal products. The most common printing lamination is used to create mock-ups.

Layer fusing

This method of 3D printing is based on the use of light alloy materials. Extruders available in the printer are not capable of withstanding high temperatures. Therefore, it is almost impossible to create objects from pure metal and alloys. Thus, the developers of consumables began to produce special composite raw materials. An example of such a solution is a material consisting of thermoplastic and bronze powder.

A metal printer of this type prints items that can not be distinguished from an all-metal product in appearance. But the physical properties of such objects are much worse. Therefore, layer-by-layer fusing is used exclusively to create mock-ups, souvenirs, and interior items. Now, engineers are looking for industries where it is permissible to use this production technology. Thus, a thermoplastic with a metal filler can be used for printing electronic boards.

Selective laser and direct sintering

Selective laser sintering of metals allows you to work not only with a durable material, but also with thermoplastic. Here, the creation of three-dimensional objects occurs with the help of laser installations by sintering a metal powder. Quite often, to reduce the power of laser emitters on a metallic material, a more low-melting coating is applied. In such cases, to increase the strength of finished products, additional sintering and impregnation with metals are required.

A variety of the described method is direct laser sintering of metals. This technology is focused on working with pure metal powder type. To realize this goal, the 3D printer has special sealed chambers filled with inert gas. Also, the printing press uses the heating of the consumable material to the temperature at which it melts, but does not boil yet. This allows you to reduce the printing time and save on the power of laser installations.

Printing by laser sintering occurs in layers. On the working platform, the machine applies a thin layer of heated powder, the particles of which are sintered together and with the previous layer. The laser beam constantly changes its direction with the help of a mirror system.

Laser sintering makes it possible to create complex structures without additional supports. Thus, this technology is used to create high-precision parts that do not require subsequent machining, as well as for the production of integral models of a level of complexity that can not be performed by conventional casting.

Laser sintering allows you to work with steel, nickel alloys, titanium, precious metals, etc.

Selective laser and electron beam melting of metals

Although the models obtained by laser sintering of metal are of high quality, they have limited application. The porous structure of the finished objects reduces their strength. Such products are of little use for industrial applications, but are more used to create mock-ups and prototypes. For the production of durable and load-resistant models, engineers converted direct laser sintering technology into a laser melting method. It is based on a strong thermal treatment of the metal powder to obtain a homogeneous object. Objects printed in this way do not actually differ in mechanical and physical properties from analogs manufactured by traditional methods.

In parallel with this, the technology of electron beam melting is applied. It makes it possible to create objects with the same accuracy and resolution, but has certain advantages. So, a 3D printer for metal of this type instead of electromechanical mirror systems is equipped with electronic guns. This allows the machine to operate at relatively high speeds, which improves performance without significant process complications. This technology is an excellent alternative to traditional industrial production, where additional equipment (furnaces and molds) is used.

Printers for laser and electron beam melting are mainly used for the production of parts of jet engines and gas turbines, orthopedic prostheses.

Direct laser additive construction

3D printer for metal direct laser construction used to repair finished products. The technology of such a machine is based on the principle of spraying metal powder particles onto damaged parts of an object and melting them with a laser. This method is characterized by a narrow specialization and is used exclusively for industrial purposes.

The print head of this type of printer moves in three planes and rotates about the vertical axis. Thus, it works at any angle.

Similar machines are used to repair complex machinery and large-sized products. For example, to repair aircraft engines.

The cost of a 3D printer for metal

Today the market offers a wide range of machines that allow creating three-dimensional metal objects. Their cost depends on the brand and printing technology. So, an industrial 3D printer for working with metal, on which it is possible to print an engine, costs tens of thousands of US dollars. More affordable machines can be bought much cheaper, but the quality of products will be worse. To solve this problem, engineers are developing a 3D printer for metal, the price for which will be much lower when fully operational.