## 1 Introduction  
Additive manufacturing, often referred to as 3D printing, is defined according to ISO TC 261 norm as a process in which material is joined in thin layers based on data from 3D models created via Computer Aided Design (CAD) system to manufacture the final parts [1]. Additive manufacturing includes a number of devices which differ from each other mainly in the type of material to be joined and the method of how the given material is joined, i.e., the energy source. The relative freedom in the design itself being incomparable to the conventional manufacturing methods is one of the main advantages of opting for additive manufacturing. All of the stated provide new opportunities in the development and the subsequent manufacturing of prototypes, the testing of functional samples, the application of new possibilities for modelling and manufacturing complex geometries and structures, and the related weight and cost reduction [2]. The utilization of additive manufacturing technologies also involves certain limitations, such as acquisition cost for equipment and materials, slow manufacture, and low quality and precision, with the need for further work to achieve the final desired shape and finish. It can be assumed that certain mentioned factors will be eliminated or minimized due to the recent rapid development of the additive technologies. Regardless of the above-mentioned limitations, additive manufacturing technologies are already widely present in industrial practice, and thus, in terms of manufacturing, they are already viable for certain utilization even today [3]. Such utilization includes the manufacture of moulds or parts with complex shapes. One of the advantages of additive manufacturing in the mould construction process is the manufacture of conformal cooling in which the cooling channels copy the shaped part of the mould, unlike the drilled cooling system. The conformal cooling ensures a smoother temperature distribution in the mould cavity and also reduces residual stresses in the moulding or casting. The side effect is consequent time reduction in manufacturing cycle, since the need of an additional mould cavity cooling is reduced and the manufactured part is thus more quickly demoulded [4]. There are specific problems arising from the DMLS technology utilization in the manufacturing process. One of these problems is the creation of residual stresses during the sintering process. Cracks and fractures, which result in geometrical inaccuracies of the manufactured part, can occur particularly on the edges of the manufactured model due to the stress effects. A dangerous situation occurs when the manufactured part is being completely torn off from the platform of the machine and a collision between the manufactured part and the moving parts of the machine occurs, thus causing damaged. The moving part of the machine is a ceramic knife that evenly applies the powder material prior to sintering of each layer. A collision between this part and the knife occurs when an already created part of the model is torn off and moved in the direction of the \(z\)-axis [5]. [PERSON] and colleagues used a voxel-based methodology in their research of model orientation optimization in order to achieve residual stress reduction. The main focus of the work is the achievement of a reduction of residual stresses and overall material consumption. When variants of components with and without optimization were compared, the results showed a reduction in residual stresses as well as a reduction in material consumption and production time [6; 7]. A study by [PERSON] et al. experimentally investigates residual stresses in the DMLS process in steels by X-ray diffraction. The process parameter for the sample was optimized for the highest possible model density (\(\geq\)99.95%). The determined magnitudes of the residual stresses were subsequently compared with the values after the heat treatment. They concluded that additional heat treatment has a positive effect on residual stresses, hence it almost completely eliminates them [8].