Printing in metal – the SLM method

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Printing in metal – about the SLM method

A few words about selective fusion technology

From a technological point of view, the SLM 3D method is very similar to the SLS method. However, instead of sintering polyamide powders, metal 3D printers, as the name suggests, use metal powders. The machine applies a thin layer of powdered metal to the work surface, and then selective laser beam melting technology sinters specific points that together form the base of the printed model. The work table is then lowered, another layer of powdered metal is applied, which will also be sintered using the laser beam. The process is repeated until a model with the specified geometry is obtained. After printing, it is necessary to wait until both the print chamber and the printed model have cooled down. Finally, the model is cut off from the work table and any supports, which are necessary when printing models with complex geometries, are removed.  In this way, the ‘suspended in air’ structures are prevented from falling.

Industrial application of SLM

SLM technology is increasingly making bold inroads into the tooling, biomedical engineering, dental, automotive and even aerospace industries. Thanks to the possibilities offered by metal printing, it is possible to create functional yet highly durable machine parts, mouldings, rigid housings, injection mould tools and even heat exchangers and heat spreaders. Tyre manufacturers are also increasingly using additive technology to produce tyre moulds – a much faster and cheaper solution to make the most of three-dimensional geometry.

Advantages of SLM

DMLS/SLM technology has been developed since 1993, but the first commercial devices did not appear until 2002 – this was the EBM S12 printer dedicated to the implant industry. The devices available on the market today are much more technologically advanced and metal 3D printing is becoming increasingly popular. This is because it is a technology with great potential and a large number of advantages. The SLM method makes it possible to significantly reduce unit costs when producing parts with very complex geometries. Another significant advantage is the manufacturing time, which in some cases can be accelerated by up to 90 % in comparison to traditional machining methods. It also makes it possible to produce parts that are not feasible with CNC machine tools.

SLM printing materials

Metal 3D printing can be realised using the following materials present in powdered form:

  • Aluminium AlSi10
  • Aluminium AlSi12
  • Titanium
  • Inconel IN718
  • Stainless steel AiSi 316L
  • Maraging steel
  • Cobalt chrome for dentistry
  • Cobalt chrome for orthopaedics

Each has specific properties that determine specific applications. 316L stainless steel, for example, is used to print parts that are to come into contact with food, while Inconel IN718 is used for models that need to withstand extreme temperatures. Its heat resistance is as high as 700°C.

Take a look at a sample of what our 3D printer shop has to offer: