A bemutatott jelenséget egy mérésre készülő próbatestsorozat gyártása közben észleltük, melynél a mérés eredeti célja az FDM technológiával gyártott alkatrészek mechanikai tulajdonságainak javítása a lehető legegyszerűbb módon.

Abstract It is a long-lasting task to understand heat conduction phenomena beyond Fourier. Besides the low-temperature experiments on extremely pure crystals, it has turned out recently that heterogeneous materials with macro-scale size can also show thermal effects that cannot be modeled by the Fourier equation. This is called over-diffusive propagation, different from low-temperature observations, and is found in numerous samples made from metal foam, rocks, and composites. The measured temperature history is indeed similar to what Fourier’s law predicts but the usual evaluation cannot provide reliable thermal parameters. This paper is a report on our experiments on several rock types, each type having multiple samples with different thicknesses. We show that size-dependent thermal behavior can occur for both Fourier and non-Fourier situations. Moreover, based on the present experimental data, we find an empirical relation between the Fourier and non-Fourier parameters, which may be helpful in later experiments to develop a more robust and reliable evaluation procedure.

The use of three-dimensional (3D) printing technologies is an ever-growing solution. The product realized in many cases is applicable not only for visual aid, or model, but for tool, or operating element, or as an implant for medical use. For correct calculation, a proper model that is based on the theory of elasticity is necessary. The basis of this kind of model is the knowledge of the exact material properties. The PLA filament has been used to perform this study for matrix material. Our presumption is that the different layers do not fuse completely, and they do not fill up the space available. The failures between the layers and the deposited filaments and the layer arrangement could be the reason for the direction-dependent material properties of the 3D printed objects. Based on our investigation, we can conclude that the increase of the layer thickness and printing speed adversely affect the mechanical properties of the product.

In this study the properties of HT-PLA were determined with tensile tests.The influence of cooling was determined and influence of manufacturing environment shown to be predictable.Heat resistant 3D printing materials can be widely used in the manufacturing process but these materials are relatively expensive.HT-PLA is one of the cheapest materials with these parameters.

Abstract In this study the properties of HT-PLA were determined with tensile tests. The influence of cooling was determined and influence of manufacturing environment shown to be predictable. Heat resistant 3D printing materials can be widely used in the manufacturing process but these materials are relatively expensive. HTPLA is one of the cheapest materials with these parameters.

Additive production technologies made the realization of individually designed, highly complicated geometric structures in practically all fields of industry and human therapy (implantation) possible. In order to minimalize the risk of failure originating from production technology the continuous development of measurements technologies provides the possibility to track the parameters of production and if necessary to ensure their modification. The great number of recorded production data (big data) at the same time can be used in the quality control of the product.

In many situations the result of the topology optimization or generative design can be manufactured only by additive manufacturing technologies. It is also important to know how the optimised shape behaves from the mechanical stiffness, the manufacturing technology and beneficial point of view. These two different goals can be combined and just the infill properties can be changed and optimised within the main body of 3D printed part.

Az utóbbi években egyre több helyen alkalmazzák az additív gyártástechnológiákat az egyedi, valamint a kisszériás gyártásban. Ilyen esetekben az alkatrésznek valós körülmények közt is működőképesnek kell maradnia. Ez azt jelenti, hogy teherviselőnek is kell lennie. Sok esetben szilárdsági szempontból már megfelelnek az anyagok. Ugyanakkor sok esetben (gépalkatrészek, kültéri felhasználás) a modelleknek nagyobb hőmérsékleten is megbízhatóan kell működniük. Erre kínál lehetőséget a legelterjedtebb additív gyártástechnológia esetében (FDM) egy új, hőtűrő anyag a HT PLA. Sok esetben a hűtés alkalmazása elengedhetetlen a gyártás során, különösen a nagy túllógásokkal tűzdelt alkatrészek esetében, ahol szükséges az anyag mielőbbi megszilárdulása a megfelelő felületminőség eléréséhez. Cikkünkben a gyártás során alkalmazott hűtésnek a mechanikai szilárdságra gyakorolt hatását vizsgáltuk.

Nowadays the different 3D printed components are often produced for direct use. In this case the components need to be mechanical designed, therefore the material properties must be well known. It is a fact that the printing parameters have a significant effect on the printing quality. The interference between the printing parameters and the mechanical solidity is well known however the reason for this phenomenon is not. For a deeper investigation a scanning electron microscope is needed. Our study is focused on the potential evaluation of results with the help of the CAD software.