The article presents the results of microstructural characterization of newly developed three-layer thermal barrier coating (TBC) after isothermal oxidation test. Bond coats were deposited by the overaluminizing of MCrAlY coating deposited by low-pressure plasma spraying (LPPS) process. The outer ceramic layer of yttria-stabilized zirconia was deposited by the plasma spray physical vapor deposition process. The TBCs with MCrAlY bond coat without aluminizing process was produced by LPPS as well. The isothermal oxidation test at 1,100°C for 1,000 h showed that the thickness of the thermally grown oxides alumina oxide layer on overaluminized bond coats was significantly thinner in comparison with conventional LPPS-sprayed MCrAlY bond coats. The possibility of the presence of NiAl and Ni3Al phases in the outer zone of overaluminized bond coat after the oxidation test was observed.
New materials and filaments dedicated to 3D printing were obtained using the fused deposition modeling method, and the properties of the produced materials were investigated. Polylactide was used as a polymer base for the assays because of the desired properties of the polymer, mainly biodegradability, and the matrix was refilled by the addition of metallic nanofillers, such as bronze, copper, brass, and steel. For the composites obtained, mechanical properties were investigated to determine the dependence of the obtained results on the content and type of filler used and on the method of fabrication of the fittings. It was found that the additives present in the polymer matrix increased the fluidity of the material. The best results were obtained for the compositions with bronze and steel in which the mass flow rate was 72.97 and 79.99 g/10 min, respectively. The filled material that had lower hardness was measured by Rockwell and the impact strength was measured by Charpy. In addition, it was found that injection-molded parts obtained much better mechanical properties than those obtained by 3D printing.
In recent years, a rapid increase in the use of three-dimensional (3D) printing technologies in medicine, especially in the manufacturing of the diagnostic models, can be observed. In some cases, there is a need to fabricate transparent models that allow visualization of internal structures of the object. Unfortunately, techniques used to manufacture such models are often very expensive and time-consuming. The above-mentioned issues were the motivation for developing a new method of fabrication transparent models for visualization of internal structures for planning surgical treatments. This paper presents the process of making transparent models using the newly developed method – the stacked layers method. In order to compare this new method and one of the most common 3D printing technologies – fused deposition modeling (FDM) – the models for two medical cases using both of these methods were fabricated. As a result of this work, it can be concluded that the stacked layers method provides faster and cheaper way of making transparent medical models. The main features of fabrication process that have a huge impact on quality of the models made by new method were pointed. The results of this study suggest that models fabricated with the use of this method can be useful as a diagnostic tool in medical applications for planning surgical treatments.
In this article, a study of nonmetallic inclusions introduced during the casting process of the aluminum–silicon alloy is presented. The samples were investigated using a scanning electron microscope to find the chemical composition and X-ray tomography to check the volumetric content of the non-metallic inclusions. The samples were made from AlSi7Mg alloy, used for car wheels, with 7% weight content of Si, 89% of Al, and 0.3% of Mg. The main goal of our investigations was to find out the chemical composition of the impurities and to identify the stage of the casting process at which the impurities are introduced.
The development of software applications and the use of VR (Virtual Reality) techniques allow to improve the company’s financial result. The construction of models of robotic stations with robots using Virtual Robot technology allows to determine the time of the machining process. It allows its optimization through the selection of accelerations, tools, tooling strategies, and so on. Determining the time of a technological operation translates into savings. This allows you to decide on the purposefulness of the investment. In addition, modern software add-ons, for example, Signal Analyzer in RobotStudio, allow you to monitor the electricity consumption of a robotic station. The article presents a solution showing how, based on the construction of digital models and the use of VR, we can conclude about the profitability of the investment.
Virtual testing and hybrid simulation have become an important trend in airplane design and validation. The traditional Testing Pyramid (or Building Block) approaches that emphasis on uniaxial coupon test and full structure certification test are being challenged. Researchers are trying to use advanced testing and simulation methods to replace the Testing Pyramid approach.
Before physical testing, virtual testing can be conducted to simulate the physical test. Virtual model of the full testing system including controller, actuators, and fixtures can be constructed and validated. In this work, an example has been developed and validated to show the potentials of the virtual testing process.
Hybrid simulation is an approach of analyzing an analysis model and physical structure integrated system under realistic loading conditions. Hybrid simulation combines the lab testing with numerical analysis to explore the benefits of both methodologies. In this study, a hybrid simulation for a simplified airplane wing was conducted to demonstrate the process.
Virtual testing and hybrid simulation are alternative methods of Testing Pyramid approach. Full scale tests are still required for certification but the more that is known about the test article, the greater chances of success in the full-scale certification testing.
Currently, scientists are striving to produce innovative textile materials characterized by special properties. Therefore, attempts have been made to use physical and chemical vapor deposition techniques to modify the surface of textile materials, i.e., nonwovens, fabrics, and knitted fabrics. By using these techniques for modifying the basic materials, researchers have obtained textiles with novel properties, which are used in shielding materials, textronics, or clothing, as well as in specialized accessories. The PVD process can be applied for almost all materials. The physical vapor deposition process allows for obtaining layers of different thicknesses and with various physical and chemical properties. This article is a review of the latest state of the art on the use of various methods of physical vapor deposition in textiles destined for different purposes.
The paper presents the concept of installation of an electricity generator and en energy store inside a roller of belt or roller conveyor. Accordingly, the use of a generator-pulley does not require any structural changes to be made to an existing conveyor. In addition, the user will be able to power distributed sensors network for monitoring the operation of the belt conveyor anywhere on its route.
The objective of this study was to investigate the carbon dioxide (CO2) emissions of an airport, to determine if strategies are helping to achieve sustainability targets. Kansai International Airport was selected as the case study, and it is Japan’s third largest airport and there was readily available comprehensive data to enable a study to be undertaken. The airport has a dedicated environmental division and has implemented various initiatives over the past decade or so to reduce the airport’s impact on the surrounding environment, especially since it is in Osaka Bay. The research used an exploratory design, with an initial qualitative case study, followed by a quantitative longitudinal study, utilizing correlation to assess trends over time. Results showed statistically significant reductions in carbon dioxide (CO2) emission from the three facets of airport operations, both in terms of the number of passengers and number of aircraft serviced by the airport. As a result, the initiatives undertaken at Kansai International Airport could be adapted and used by other airports to help reduce their carbon dioxide emissions.
Smart devices and their connections to the Internet of Things (IoT) have been the subject of many papers in the past decade. In the context of IoT in transportation, one feature is the smart junction. This research deals with this junction, where several cars approach the intersection from different directions, and a smart traffic light must decide regarding the time intervals of red and green light in each direction. Out novel approach is based not only on the number of vehicles in each lane, but also on the social characteristics of the passengers (e.g. a handicapped person, a driver with no previous traffic violations). These factors will be gleaned from IoT network sources on cars, traffic lights, individuals, municipality data, and more. In this paper, we suggest using a VCG (Vickrey-Clarke-Groves) auction mechanism for the intersection scheduling, combining the social characteristic with a benefit parameter that expresses the passenger’s subjective perception of the importance of crossing the intersection as soon as possible. Our simulation results show the efficiency of the suggested protocol and demonstrate how the intersection scheduling depends on the passengers’ preferences, as well as on their social priorities.