Evaluation of the impact energy of the samples produced by the additive manufacturing technology

The article covered the evaluation of the impact energy, notch toughness and morphology of the fracture surfaces of the specimens manufactured by the Direct Metal Laser Sintering Technology. Specimens without heat treatment with no notch were not broken through in course of testing, therefore there was no fracture surface present. The heat treatment resulted in the increase in hardness values. The values of impact energy after the heat treatment was approximately 60 % lower. Ductile intergranular fracture with more or less segmented dimple morphology appeared in every specimen. At places where the internal plastic bond was resisting the test, cracks remaining after particles broke away from the surface can be seen as craters

The ethical desirability of moral bioenhancement: A review of reasons

Background: The debate on the ethical aspects of moral bioenhancement focuses on the desirability of using biomedical as opposed to traditional means to achieve moral betterment. The aim of this paper is to systematically review the ethical reasons presented in the literature for and against moral bioenhancement. Discussion: A review was performed and resulted in the inclusion of 85 articles. We classified the arguments used in those articles in the following six clusters: (1) why we (don't) need moral bioenhancement, (2) it will (not) be possible to reach consensus on what moral bioenhancement should involve, (3) the feasibility of moral bioenhancement and the status of current scientific research, (4) means and processes of arriving at moral improvement matter ethically, (5) arguments related to the freedom, identity and autonomy of the individual, and (6) arguments related to social/group effects and dynamics. We discuss each argument separately, and assess the debate as a whole. First, there is little discussion on what distinguishes moral bioenhancement from treatment of pathological deficiencies in morality. Furthermore, remarkably little attention has been paid so far to the safety, risks and side-effects of moral enhancement, including the risk of identity changes. Finally, many authors overestimate the scientific as well as the practical feasibility of the interventions they discuss, rendering the debate too speculative. Summary: Based on our discussion of the arguments used in the debate on moral enhancement, and our assessment of this debate, we advocate a shift in focus. Instead of speculating about non-realistic hypothetical scenarios such as the genetic engineering of morality, or morally enhancing 'the whole of humanity', we call for a more focused debate on realistic options of biomedical treatment of moral pathologies and the concrete moral questions these treatments raise

Mathematical modeling of the mechanical characteristic of the activated PTFE-matrix using the method of planning the experiment

In this paper, the influence of the parameters of the technological process of mechanical activation on the physical characteristics of the polytetrafluoroethylene (PTFE) matrix is investigated. The paper presents a mathematical model of the dependence of breaking strength on the time of activation and rotating speed of working organs of a mill. Mathematical modeling is performed by the method of orthogonal experiment planning. The result of the study was a mathematical relation that explains the connection between the technical characteristics of the process of manufacturing a fluoroplastic composite and the mechanical characteristics of the material. The statistical analysis of the experimental results is performed and the adequacy of the mathematical relations obtained is estimated. On the basis of the analysis of the obtained data, it can be concluded that the theoretical model obtained is adequate and suitable for performing the corresponding technological calculations. On the basis of the performed calculations, the conclusion is reached on the optimal technological mode of preparing the PTFE-matrix. The analysis shows that theoretical calculations confirm the experimental value of technological indicators under optimal operating conditions of the mill. Thus, the obtained dependence of breaking strength from the technological parameters of the activation process can be embedded in the algorithm for selecting the technological mode that ensures the output of products with specified quality indicators

Examination of material manufactured by direct metal laser sintering (DMLS)

This article is concerned with assessing microstructural properties of metal component manufactured by additive DMLS technology. Two series of samples were assessed. The first one was manufactured without heat treatment. Samples in the second series were treated with heat in order to assess increase in hardness and influence on modification of microstructure. Subsequently, values of hardness were measured by Vickers Hardness Test and modification of microstructure was observed by optical microscope. Evaluations were carried out in three planes in order to assess the differences in layering of material during its processing. Differences in values of hardness and microstructural components were discovered by examination of changes in three planes

Determination of the EOS maragingsteel MS1 material resistance at low temperatures

This article deals with determination of the EOS MaragingSteel MS1 material resistance at different low temperatures. Material resistance was evaluated in two types of standardized specimens. The impact energy at the specimens tested at 10 °C, values for the specimens with no notch were compared to the V - notch specimens, higher by approximately one - third. When the temperature dropped to 0 °C, the values of the impact energy slightly decreased as well. It therefore follows that lower temperatures result in decrease in the values of the impact strength. This experiment provided us with the opportunity to find out whether the decrease in temperature impacts the resistance of the tested material