## 2 The State of Research in the Application of AM Technology in Polish Manufacturing Companies  
Polish manufacturing enterprises make little use of additive technologies (2.4% according to GUS data). In 2017, 3D printing technology was most often used by enterprises in the Dolnoslaskie (3.5%), Podkarpackie (3.2%) and Swietokrzyskie (3.1%) ovivodships, yet least frequently so in the Lubelskie (1.0%) and Lubuskie ovivodships (1.1%). In 2017, 3D printing technology was mainly used to create prototypes or models for personal use (1.8%), of which 10% were mainly for large enterprises. The least frequently used 3D printing was to create goods for sale, excluding prototypes or models (0.4%) and to create goods for use in production processes, excluding prototypes or models (0.5%). Spatial printing was mainly used by large enterprises employing 250 people or more. Based on the analysis of the literature on the subject [5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29], the characteristics of AM technologies used have been broken down into separate dimensions:  
* In automotive industry companies:
* Production process of machinery parts and equipment made of plastic and metal, including high precision mechanical parts and sub-assemblies,
* Production process for functional prototypes and co-operating mechanisms,
* Production process in models used in strength tests, tests and modelling. * In metal industry companies:
* Prototype and model production process,
* The production process for injection moulds, foundry moulds, highly precise metal structures and other elements with a complex geometry or requiring high mechanical properties, the production of which would often not be possible using foundry technologies,
* The process of the repair and regeneration of complex damaged metal parts. The following AM technologies according to the defined dimensions were identified for further research (Table 1). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{4}{c}{**Automotive Industry Companies**} \\ \hline  
\begin{
\begin{tab  
In the processes carried out in AM technologies, the following technologies can be distinguished: technologies using a powder-filled platform, the powder bed technology, so-called, occurring in such technologies as Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS), Electron Beam Melting (EBM) and also direct deposition technology, in such technologies as Electron Beam Additive Manufacturing (EBAM), Laser Engineering Net Shape (LENS) [30]. By evenly placing the powder on the working platform, the material feeding system has the advantage because the model does not need to have brackets generated. Moreover, the powder bed gives the opportunity to make models in the higher parts of the working chamber [27]. Selective powder micro-metallurgy (SLM) has many advantages related to accuracy of performance, versatility and the possibility of the complete elimination of the assembly phase, by sintering ready-made constructions. In the selective laser melting of powders of various metals, stainless steel powders are most often used. Unlike Selective Laser Sintering (SLS), the powder is re-melted through a laser beam, which significantly affects the tightness of the model and the lack of pores [27]. Metal additive manufacturing (MAM) is becoming a popular industrial production solution. Metal AM is characterised by two leading methods using metal powders, namely SLM/DLMS which is used mostly in the automotive industry and electron beam melting (EBM) [31; 32]. The benefits of using additive manufacturing techniques are observed in the production of engine parts, fuel systems or turbines with a complex geometry and with defined aerodynamic properties. In addition, the technology of laser sintered metal powders enables the development of advanced and lightweight structures that combine high strength with a weight reduction of up to 60%.