Journal of Casting & Materials Engineering
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ISSN 2543-9901
Issue Date
2020
Volume
Vol. 4
Number
No. 1
Description
Journal Volume
Journal of Casting & Materials Engineering
Vol. 4 (2020)
Projects
Pages
Articles
Influence of structural characteristics on the mechanical properties of FDM printed PLA material
(AGH University of Science and Technology Press, 2020) Szczepanik, Stefan; Nikiel, Piotr
The present study reports on the influence of printing process parameters, architecture, raster, infill orientation and filling on the density, macrostructure, and mechanical properties, including impact resistance, of biodegradable polymer parts fabricated in polylactide (PLA) on a desktop printer. It complements and considers phenomenologically the results of recently published similar studies, including the use of recycled filament. In our study, complex mechanical properties for the samples printed at the same time on a Replicator 2 printer were investigated. Three samples were printed for each test. Full mechanical characteristics (tensile, compression and bend strengths and impact resistance) of the printed PLA material are reported. This is the novelty in comparison to other studies, where the samples test were printed individually or in a series for each test. The shape and thickness of the layered macrostructure, the presence of holes inside the layers, the number of shell perimeters and the fill density all influenced the tensile properties of the printed materials. These results show the possibility of printing with a 0.3, i.e. shorter printing time than 0.1, 0.15 and 0.18 mm layer thicknesses also reported, without significant decrease in mechanical properties. It is interesting to note that the compressive strengths, the yield of 70-80 MPa and a UTS 113-120 MPa for the printed material with a fill density of 94-96% are comparable with those of aluminum.
Surface remelting of mold inserts made of NC11 steel
(AGH University of Science and Technology Press, 2020) Trytek, Andrzej; Tupaj, Mirosław; Majerník, Ján; Gašpár, Štefan; Zbyrad-Kołodziej, Wiktoria; Łysiak, Karol
In the study presented in this paper, the effect of a concentrated heat stream on geometry, microstructure, and hardness of superficial remeltings on NC11 steel is examined. The material is used for disposable mold inserts exposed to intensive abrasive wear in the course of the press-molding of hard aggregate stampings for refractory bricks. As a result of local remelting, the hardness of the steel surface increased and its microstructure was altered. Macro- and microstructure of the remelted areas was examined with the use of optical microscopy and measurements of remelting area geometry were carried out for different parameters of the remelting process. Hardness measurements were taken in the remelting area and in the heat-affected zone. The state of stress in the material before remelting and in the remelted area was also evaluated.
Connecting castings for operation under conditions of cyclic temperature changes
(AGH University of Science and Technology Press, 2020) Drotlew, Andrzej; Piekarski, Bogdan
The separable connections used in technological equipment of heat treatment furnaces (OTP) are described in this study. The equipment is used for the heat treatment of charges, i.e. for the thermal and thermo-chemical treatment of parts of machines and devices. OTP is used for the charge formation and its transport before, during and after heat treatment operations. Accessories of this type are usually compact structures composed of several or several dozen cast elements. The main components are grates and pillars, which form an outer contour of the OTP and also allow for the correct arrangement of heat-treated parts. To form a relatively rigid structure composed of the grates and pillars, it is necessary to join these components together. For this purpose, various types of separable connections are used, mainly of a cylindrical shape with threaded parts. The subject of this study is focused on the construction and operating conditions of typical OTP structures, as well as the methods of fastening the pillar in a grate, i.e. on the design of the bottom part of the pillar and the hole in the grate in which this pillar is embedded.