The article details the principle behind Fused Deposition Modelling (FDM) technology. Strength tests were carried out on a Stratasys FORTUS 400mc industrial 3D printer. Prints of the strength specimens were made in different orientations in the working chamber of the machine.
PL
W artykule szczegółowo przedstawiono zasadę działania technologii FDM (Fused Deposition Modeling). Zostały przeprowadzone badania wytrzymałościowe na przemysłowej drukarce 3D Stratasys FORTUS 400mc. Wydruki próbek wytrzymałościowych zostały wykonane w różnej orientacji w komorze roboczej urządzenia.
In present study, Fe-22Cr-4.5Al oxide dispersion strengthened ferritic alloys were fabricated using a pre-alloyed powder with different minor alloying elements, and their microstructures and tensile properties were investigated to develop the advanced structural materials for high temperature service components. Planetary-typed mechanical alloying and uniaxial hot pressing processes were employed to fabricate the Fe-Cr-Al oxide dispersion strengthened ferritic alloys. Microstructural observation revealed that oxide dispersion strengthened ferritic alloys with Ti, Zr additions presented extremely fine micro-grains with a high number density of nano-scaled oxide particles which uniformly distributed in micro-grains and on the grain boundaries. These oxide particles were confirmed as a fine complex oxide, Y2Zr2O7. These favorable microstructures led to superior tensile properties than commercial ferritic stainless steel and oxide dispersion strengthened ferritic alloy with only Ti addition at elevated temperature.
In this study, the effect of calcium treatment on the mechanical properties and fatigue behavior of low carbon steel material is investigated. By applying calcium treatment after aluminum deoxidation for steel cleanliness, the aim is to transform the inclusions into harmless structures and produce cleaner liquid steel. As a result of the study, calcium treated material’s tensile strength slightly increases while fatigue life decreases. SEM studies were conducted to evaluate the results and it was observed that while elongated inclusions were observed as well as spherical shapes in the untreated sample, the inclusions generally had a spherical shape in the calcium treated sample. After the steel cleanliness process, the mechanical properties of the samples were improved. The tensile strength of the calcium treated sample increased slightly. However, a significant decrease in fatigue strength was observed depending on brittle inclusions that occur as a result of the calcium treatment process.
Developing aluminum with good mechanical properties like hardness, tensile strength, and normal flow stress, Equal Channel Angular Extrusion (ECAE) method has been suggested as a suitable metal forming process. The load applied and extrusion temperature normally infl uences the flow stress behavior in extruded products and de- termine their mechanical properties. Consequently, how these factors affect mechanical behavior and flow stress of Al 6063 processed by ECAE was examined in this study. Extrusion temperatures were 350°C, 425°C, and 500°C with die angles of 130°, 140°, and 150°. 5 mm/s of ram speed was applied. Each extrudate’s tensile strength and hardness were measured using a Universal Testing Machine and a Rockwell hardness tester. Samples with equal dimensions and properties were also modeled using the Qform software at the extended die angle and temperature for proper analysis of flow stress in the extrudates. According to experimental results, the temperature had a greater effect on the tensile strength and hardness of the billet than the die angle. The extrudates’ grains also became finer as the billet temperature rose. Simulation findings showed that higher billet temperature led to a decrease in the extrudates’ flow stress. The simulation also demonstrated that billet temperature had a greater impact on extrusion load than die angle, with a maximum extrusion load of 5.5 MN being attained at 350 °C.
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The aim of the paper was to present issues related to the determination of the influence of selected technological factors: the method of surface preparation and type of adhesive on the strength of adhesive joints made of steel sheet C45. As a method of surface preparation the process of shot-blasting with the use of three types of abrasives differentiated in terms of the degree of its wear was used. The adhesive bonds were made with the use of two two-component epoxy adhesive compositions based on Epidian 57 epoxy resin and PAC and Z-1 curing agents combined with the resin in the recommended proportions. The measurements of roughness and topography of surfaces prepared for the bonding process were also carried out. After the curing process, strength tests of adhesive bonds were performed on the Zwick/Roell 150 testing machine, according to PN-EN 1465 standard. It was noted, among others, that with increasing wear of the abrasive used in the surface preparation process, the value of adhesive bonds strength decreased and the higher strength of adhesive bonds was characterized by adhesive joints made with Epidian57/Z-1/100:10 adhesive. The obtained results were subjected to statistical analysis.
PL
Celem artykułu było przedstawienie zagadnień związanych z określeniem wpływu wybranych czynników technologicznych: sposobu przygotowania powierzchni oraz rodzaju kleju na wytrzymałości połączeń klejowych wykonanych z blachy stalowej C45. Jako sposób przygotowania powierzchni wykorzystano proces śrutowania z wykorzystaniem trzech rodzajów ścierniw zróżnicowanych pod względem stopnia jego zużycia. Połączenia klejowe wykonano przy użyciu dwóch dwuskładnikowych kompozycji klejowych epoksydowych bazujących na żywicy epoksydowej Epidian 57 oraz utwardzaczy PAC i Z-1 łączonych z żywicą w zalecanych proporcjach. Przeprowadzono także pomiary chropowatości oraz topografii powierzchni przygotowanych do procesu klejenia. Po procesie utwardzania dokonano prób wytrzymałościowych połączeń klejowych na maszynie wytrzymałościowej Zwick/Roell 150, zgodnie z normą PN-EN 1465. Zauważono m.in., że wraz ze wzrostem stopnia zużycia ścierniwa użytego w procesie przygotowania powierzchni, wartość wytrzymałości połączeń klejowych malała, a wyższą wytrzymałością charakteryzowały się połączenia klejowe wykonane przy użyciu kleju Epidian57/Z-1/100:10. Uzyskane wyniki poddano analizie statystycznej.
The food packaging material and its quality assessment based on permeability, tensile strength, swelling, transmittance, and biofilm formation are discussed in this chapter. The semi-Markov model of food packaging material quality change process is introduced and its characteristics are determined. Next, the safety and resilience indicators are proposed for multi-state analysis, identification, prediction and optimization of packaged food product consumption safety.
The effect of unmodified and stearic acid-modified calcium carbonate (5, 10, 20 and 30 wt%) on selected properties (tensile strength, puncture resistance, haze and gloss) and processability of polypropylene films (MVR, extensional viscosity) was investigated. The composites were obtained in the twin-screw extrusion process with cold granulation, and the films in the single-screw extrusion process, using a flat die head (so-called cast films) and a chill roll type cooling and pull-back device. It has been shown that stearic acid is an effective modifier of polypropylene processing properties both under shear and tensile flow conditions (lower extensional viscosity of films containing modified calcium carbonate).
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Zbadano wpływ dodatku 5, 10, 20 oraz 30 % mas. niemodyfikowanego imodyfikowanego kwasem stearynowym węglanu wapnia na wybrane właściwości użytkowe (wytrzymałość na rozciąganie, odporność na przebicie, zamglenie, połysk) iprzetwórcze folii polipropylenowych (MVR, lepkość wzdłużna). Kompozyty otrzymano w procesie dwuślimakowego wytłaczania z granulacją na zimno, a folie w procesie jednoślimakowego wytłaczania, przy użyciu głowicy płaskiej (tzw. cast films) oraz urządzenia chłodząco - odciągającego typu chill roll. Wykazano, że kwas stearynowy jest efektywnym modyfikatorem właściwości przetwórczych folii polipropylenowych zarówno w warunkach przepływu ścinającego, jak i rozciągającego (mniejsza lepkość wzdłużna folii zawierających modyfikowany węglan wapnia).
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Continuous drive friction welding (CDFW) is a solid-state joining procedure that can be used to join various similar and dissimilar materials. High-density polyethylene (HDPE) is a thermoplastic that can replace many traditional materials. Utilizing experimental design procedures such as response surface method (RSM) is a reliable approach for determining the most significant process parameters and optimizing the desired responses. The current study employed an RSM experimental design to investigate the effects of the process parameters for welding HDPE rods using CDFW. The design evaluated the process parameters and three outcome responses: the maximum welding temperature, the axial shortening, and the tensile strength (TS). The combination of the three responses can allow achieving high-efficiency welds. The results showed that it was possible to achieve high-efficiency welds while maintaining axial shortening and controlling temperature. A TS >65% of the parent material's strength with an axial shortening of <3 mm was achieved.
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This research investigates the effect of using hard ceramic SiC particles on the mechanical and tribological properties of Al6082 alloy. This investigation is performed by mixing various contents of SiC as weight percentages of 0, 1, 2, 3, and 4% with Al6082. Mechanical tests, such as tensile strength and hardness tests, are adopted for this composite (Al6082/SiC) at various contents of the filler (SiC). Besides, the wear test is conducted for the Al6082/SiC composite at various normal loads (10, 15, 20, 25, and 30 N) and sliding distances (200, 400, 600, 800, and 1000 m). Taguchi’s approach is used to create the experimental runs’ matrix. The findings reveal that the mechanical properties improved with increasing the percentage of SiC reinforcement. The tensile strength and Rockwell hardness of Al6082 increased by about 24.6 and 14%, respectively, using 4% of SiC particles. Regarding the tribological behavior, the average wear of Al6082 alloy decreased with increasing the percentage of SiC reinforcement due to higher hardness of reinforcement in Al6082/SiC composite. At the same time, an increase in the normal load and sliding distance led to a decrease in wear due to increasing plastic deformation at elevated loadings and larger area contacts.
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The presence of particles and fibers as reinforcement in a polymer matrix greatly enhances the mechanical properties. Agricultural residues and natural fibers are commonly used nowadays due to the fact that they easily decompose even after a longer period and they are eco-friendly in nature. f Fiber that was extracted from stem of Calotropis gigantea was selected as reinforcement in the present investigation. Initially the fiber was treated with a sodium hydroxide solution and CG fiber-epoxy composites were prepared. The properties of alkaline treated CG fiber-reinforced epoxy composites were further improved by the addition of particles such as chitosan, red mud and rice husk. Properties such as the tensile strength, flexural strength, impact toughness, hardness, water absorption, thickness swelling behaviour, specific wear rate and coefficient of friction were evaluated and compared. The XRD pattern of the chemically treated CG fiber-reinforced parrticle-filled epoxy composites was presented in the present study.
Optimal parameters setting of injection moulding (IM) machine critically effects productivity, quality, and cost production of end products in manufacturing industries. Previously, trial and error method were the most common method for the production engineers to meet the optimal process injection moulding parameter setting. Inappropriate injection moulding machine parameter settings can lead to poor production and quality of a product. Therefore, this study was purposefully carried out to overcome those uncertainty. This paper presents a statistical technique on the optimization of injection moulding process parameters through central composite design (CCD). In this study, an understanding of the injection moulding process and consequently its optimization is carried out by CCD based on three parameters (melt temperature, packing pressure, and cooling time) which influence the shrinkage and tensile strength of rice husk (RH) reinforced low density polyethylene (LDPE) composites. Statistical results and analysis are used to provide better interpretation of the experiment. The models are form from analysis of variance (ANOVA) method and the model passed the tests for normality and independence assumptions.
This paper studied the effect of laser welding technology on dissimilar metal welding joints of TA15 titanium alloy and Inconel 718 nickel-based alloy. The research results indicate that the laser welding of TA15 titanium alloy and Inconel 718 nickel-based alloy directly was difficult to form well, which due to the intermetallic compounds caused the joint brittle. When the pure Cu foil was used as the filling layer, the quality of the welding joints can be improved effectively. The experimental results also indicate that there were brittle intermetallic-compounds in the laser welding seam, and the laser power had an important influence on the performance and mechanical properties of the dissimilar metal joint. The maximum average tensile strength of the welding joint of 2300 W was increased to 252.32 MPa. Scanning electron microscope(SEM) results show that the fracture morphology was river pattern, a typical morphological of cleavage fracture, and the mode was brittle fracture.
In this work, 25 wheels were cast with three different grain refiners: Al5Ti1B, Al3Nb1B and MTS 1582. Samples were machined from the wheels to check the mechanical properties. It was found that Nb grain refinement had the lowest grain size (260 mm) and highest tensile properties (yield strength of 119-124 MPa and ultimate tensile strength of 190-209 MPa). Al5Ti1B and MTS 1582 revealed quite similar results (110 MPa yield and 198 MPa ultimate tensile strength). The fading of the grain refining effect of Al5TiB1 master alloy was observed in both Nb and Ti added castings whereas during the investigated time interval, the fading was not observed when MTS 1582 was used.
The article presents a results of study on the impact of replacing CEM I SR3/NA by CEM III/A LH/HSR/NA on the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement (w / c) ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana - zeolite. Compressive strength tests were performed after 3, 7, 28 and 56 days, tests of tensile strength test by splitting method and flexural strength two-point loading tests. The characteristics of the air pores and the rate of water absorption by concrete surface of the samples cut out from the slabs with exposed aggregate were presented. The resistance of the surface to exfoliation after 56 cycles of freezing-thawing in NaCl solution was tested. Based on the results obtained, it was found that when designing the composition of the concrete intended for the upper layer of the pavement, it is necessary to ensure high tensile strength, appropriate in the XF4 environment and with the decrease in the w / c < 0.4, a reduction in capillary porosity of the cement paste is obtained, and the same the durability of concrete is increased due to the improved strength parameters in the contact zone between coarse aggregate grains and cement paste. The research also showed a significant influence of proper cure on the mechanical properties and durability of pavement concrete.
PL
W artykule przedstawiono wyniki badań wpływu zastąpienia CEM I SR3/NA przez CEM III/A LH/HSR/NA na właściwości mechaniczne i trwałość betonu nawierzchniowego z odsłoniętym kruszywem. Użyto kruszywa granitowe i płukany piasek. Współczynnik woda/cement (w / c) w badanych betonach wynosił 0,35 i 0,4, a część cementu zastąpiono 5% dodatkiem naturalnej pucolany (zeolit). Badania wytrzymałości na ściskanie wykonano po 3, 7, 28 i 56 dniach, badania wytrzymałości na rozciąganie metodą rozłupywania oraz badania wytrzymałości na zginanie dwupunktowe. Przedstawiono charakterystykę porów powietrza oraz szybkość wchłaniania wody przez powierzchnię betonu próbek wyciętych z płyt z odsłoniętym kruszywem. Zbadano odporność powierzchni na złuszczanie po 56 cyklach zamrażania/rozmrażania w roztworze NaCl. Na podstawie uzyskanych wyników stwierdzono, że przy projektowaniu składu betonu przeznaczonego na górną warstwę nawierzchni należy zapewnić wysoka wytrzymałość na rozciąganie, właściwą w środowisku XF4. Zauważono, że jeśli wskaźnik w / c < 0,4 nastąpiło zmniejszenie porowatości kapilarnej zaczynu cementowego, a tym samym zwiększenie trwałości betonu dzięki poprawie parametrów wytrzymałościowych w strefie styku ziaren kruszywa gruboziarnistego z zaczynem cementowym. Badania wykazały również istotny wpływ prawidłowego utwardzenia na właściwości mechaniczne i trwałość betonu nawierzchniowego.
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Rocks in nature are commonly in partially saturated conditions and exposed to dynamic loads. In this study, to explore the coupled effects of water content and loading rate, dynamic Brazilian disc experiments were conducted on Yunnan sandstone samples with four levels of water content (from air-dried to water-saturated) under various loading rates (from 100 to 600 GPa/s) using a split Hopkinson pressure bar. The test results show that for each water content, the dynamic tensile strength of sandstone is positively sensitive to loading rate. The rate dependence of tensile strength increases as the rise of water content. The change trends of tensile strength against water content depend on loading rate: as water content rises, the tensile strength displays the manner of “no change followed by fast drop” at loading rates of 10–4 and 100 GPa/s. However, when the loading rate is above 200 GPa/s, the tensile strength increases first and then declines. The turning point occurs at water content between 1.0 and 2.0%. These observations can be interpreted with the competition between water weakening and enhancing effects under different loading conditions.
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The brittle nature of concrete limits the further development, while the addition of polymer can enhance the toughness and improve the working performance. Understanding the mechanical properties and failure mode of polyurethane cement composites (PUCC) is of great significance in the field of construction engineering. To solve these issues, in this paper, the tensile and compressive properties are studied. The tensile/compressive strength, elastic modulus, toughness, strain capacity and the failure mechanism were analyzed. The results showed that compared with the reference group (RF), the compressive strength of PUCC was decreased by 33%. However, rubber powder could enhance the toughness of samples up to 1.19 times than RF. Polyethylene fiber was hard to disperse because of the poor fluidity of the matrix, therefore, the mechanical properties of PUCC did not change obviously. But due to the bridging effect of fiber, the failure mode was relative intact. Not only the irregular shape of basalt would decrease the interfacial adhesion, but also the polyurethane has weakened the cohesion. The mechanical properties of concrete were reduced because of the formation of interfacial transition zone between basalt and cement matrix. Therefore, the tensile and compressive strength was decreased by 19.7% and 11.8%, respectively. Moreover, the incorporation of basalt shortens the deformation time and intensifies the failure degree of the specimen. Moreover, this study takes a three-stage model to describe the compressive stress–strain behavior of PUCC. There is a good correlation between the constitutive model and the experimental results, and the simulation is accurate.
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Rice husk disposal has become a great challenge for Pakistan being one of the largest rice producer across the globe. Rice Husk Ash (RHA) contains sufficient pozzolanic properties which opens up opportunities for its usage as cementitious material as partial replacement of Ordinary Portland Cement (OPC). In this research RHA was added as cement replacement in different percentages by weight of cement i.e. 0%, 6%, 12%, 18% and 24% at constant mix ratio of 1:2:4 and water-cement ratio of 0.6 that is M15 grade concrete with a target strength of 15-20 MPa. The properties of concrete like workability, compressive strength, tensile strength, flexure strength, and water permeability were investigated by casting standard concrete samples in the form of cubes, cylinders and beams in addition to cost comparison study The outcomes show that workability of fresh concrete increases with an increase in RHA content and almost all concrete properties studied in this research gave more favorable results at 6% replacement level compared with the control mix.
The contemporary work manifests that friction stir welding (FSW) is a viable avenue for joining AA1100 aluminium (Al) to C12200 copper (Cu) plates. In this present study, the response of distinctive welding parameters (viz. tool geometries, tool rotational speed, tool travel speed, and tool plunging depth) on weld quality has been investigated. The present work focused on both microstructural investigation and mechanical properties examination. It has been observed that the process parameters have significant effects on weld quality. The design of the experiments has been executed considering four welding input parameters in two variables and selected L-16 orthogonal array to limit the experimental replications. It has been observed that good quality of welds produced by keeping the tool pin offset around 4mm towards the aluminium side and 2mm towards the copper side. And it has also been noticed that right-hand threaded tool pins are giving good weld quality compared to left-handed thread. The joint efficiencies for the welds E2, E14 which were welded by RHT tools were 75.3% and 74.61% and the Strength (UTS) of the welds for the same tools exhibit’s greater than the LHT tools i.e., 98 and 95Mpa. Moderate hardness values are observed for the same welds E1 and E14 with the parameters 1100rpm, 98welding speed, and 1.6mm tool plunge depth. . It also noticed that the weld quality can be significantly enhanced by using proper tool plunge and tool pin geometries compared to the other process parameters.
The article presents an analysis of the technical use aspects of the pull-off method for testing the repair layers applied to concrete elements, based on the standards requirements. The use of non-destructive testing methods is the only option in some cases. However, it is very important to pay attention to their proper use or even preparation for research. The pull-off method requires just such diligence to be able to properly interpret the obtained results. The article compares the results of the research in which the pull-off method was used in various configurations. The obtained measurement results were compared with each other and analyzed in terms of their usefulness.
PL
W artykule przedstawiono analizę technicznych aspektów użytkowania metody pull-off do badania warstw naprawczych nakładanych na elementy betonowe w oparciu o wymagania norm. W niektórych przypadkach jedyną opcją jest zastosowanie nieniszczących metod badawczych. Bardzo ważne jest jednak, aby zwracać uwagę na ich właściwe stosowanie, a nawet samo przygotowanie do badań. Metoda pull-off wymaga właśnie takiej staranności, aby móc właściwie zinterpretować uzyskane wyniki. W artykule porównano wyniki badań, w których zastosowano metodę pull-off w różnych konfiguracjach. Otrzymane wyniki pomiarów porównano ze sobą i przeanalizowano pod kątem ich przydatności.
Publikacja obejmuje wyznaczenie oraz porównanie wytrzymałości na rozciąganie i zginanie modeli wytworzonych w procesie kształtowa- nia próżniowego z żywic poliuretanowych imitujących właściwościami materiały ABS i PC. Opracowano i przyrostowo wytworzono zespolone modele zestawów próbek wzorcowych do badań wytrzymałościowych zaopatrzone w zintegrowany układ zalewowo-odpowietrzający. Na jego podstawie opracowano formy silikonowe. Proces próżniowego odlewania przeprowadzono dla żywic poliuretanowych imitujących właściwościami mechanicznymi odpowiednio poliwęglan i ABS. Proces VC (Vacuum Casting) oraz obróbkę termiczną dla poszczególnych zestawów próbek zrealizowano wg indywidualnych kart materiałowych opracowanych przez producentów poszczególnych żywic. Wytrzymałość w statycznej próbie rozciągania i trzypunktowego zginania modeli testowych wyznaczono z wykorzystaniem specjalistycznego stanowiska badawczego. Przeprowadzono analizę porównawczą wyników uzyskanych w badaniach stanowiskowych z danymi deklarowanymi przez producentów poszczególnych materiałów.
EN
The publication covers the determination and comparison of the tensile and bending strength of models produced in the process of vacuum forming from polyurethane resins imitating the properties of ABS and PC materials. Complex models of sets of reference samples for strength tests were developed and incrementally produced integrated flood and vent system. On its basis, silicone forms were developed. The vacuum casting process was carried out for polyurethane resins imitating the mechanical properties of polycarbonate and ABS, respectively. The VC (Vacuum Casting) process and thermal treatment for individual sets of samples were carried out according to individual material cards prepared by the producer of individual resins. The strength of the static tensile and three-point bending test of the test models was determined using a specialized test stand. A comparative analysis of the results obtained through bench tests with the data declared by the producers of individual materials was carried out.
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