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PL
Przedstawiono wpływ obecności grafitu jako fazy dyspersyjnej na właściwości mechaniczne warstw hybrydowych Ni-P/Si₃N₄/grafit, które osadzono metodą redukcji chemicznej na stopie glinu AW-7075. Wykonano badania morfologii powierzchni warstw metodą mikroskopii świetlnej i skaningowej. Dalszą część pracy stanowiły badania mechaniczne, czyli pomiary mikrotwardości warstw oraz ich adhezji do aluminiowego podłoża, a także analizy wpływu obecności grafitu na podstawowe właściwości materiału powłokowego. Zbadano próbki ze stopu AW-7075, na których osadzono metodą bezprądową powłoki hybrydowe i porównawczo nanokompozytowe o różnym składzie chemicznym, modyfikowanym zawartością faz dyspersyjnych.
EN
The mech. and adhesive properties of Ni-P/Si₃N₄ and Ni-P/Si₃N₄/graphite coatings deposited using the electroless method on the AW-7075 Al alloy were compared. Coatings with different chem. compns., modified by the content of dispersion phases (Si₃N₄ and graphite), were used. Microhardness and adhesion of the layers to the Al substrate were measured. The impact of the presence of graphite on the basic properties of the coating material was analyzed. The surface morphol. of the layers was examined using light microscopy and SEM. The incorporation of Si₃N₄ and graphite into the coating material resulted in a several-fold increase in the microhardness of the surface layer compared to the Al alloy.
EN
Recently, dissimilar metals have found applications in the process of resistance spot welding (RSW), particularly within the electric vehicle industry. Notably, copper and aluminum have gained significant importance in these sectors due to their advantageous characteristics for the industry requirements. The mechanical behavior of these materials is essential to maintaining structural integrity. The study aims to estimate the mechanical behavior of dissimilar RSW joints and optimize welding parameters for Cu-Al joints. Hence, understanding the joining processes in the electric vehicle industry to design reliable components. Combining different types of materials, such as T2-grade commercially pure copper sheets and aluminum AA1050 with the same thickness of 1 mm has been welded. The determination of optimal welding conditions takes into account material thicknesses and types. Through tensile-shear testing, welding parameters that yield maximal joint strength were identified. Using Minitab 19 software, the Taguchi method helped achieve optimized welding parameters. The hardness, fracture characteristics, and weld strength have been investigated. Hardness measurements were conducted across the nugget thickness and surface, offering insights into potential failure modes. The welding process involves the transition to a liquid state for the aluminum components, resulting in the formation of intermetallic compounds. Consequently, crack initiation was observed within the aluminum segments, leading to a plug-out fracture mechanism. In contrast, copper exhibits superior strength and hardness compared to aluminum, where increased hardness correlates with heightened strength. The discrepancy in hardness, especially the lower values observed on the aluminum side, caused fractures to appear within the heat affected zone (HAZ). Subsequently, this fracture propagated until pull-out failure was realized. The study revealed that dissimilar joining of Cu and Al resulted in an ultimate tensile stress of 26 MPa, while similar joining of copper showcased a strength of 98 MPa. Additionally, the symmetric join in aluminum exhibited a strength of 93 MPa. The maximum tensile shear force is equal to 512 N at a maximum welding current of 14000 A. The pull-out failure mode occurs in the Cu-Al RSW joint. The maximum hardness was noted in the fusion zone (FZ). Relevant literature sources have supported and confirmed these outcomes.
EN
Components used for the structure of the GLObal Solar Wind Structure experiment in the NASA Interstellar Mapping and Acceleration Probe space mission, made of AA6061-T6 alloy, are subjected to the coating process, where the temperature affects its mechanical properties. This paper aims to examine the impact of the coating thermal cycle on the mechanical properties of AA6061-T6 alloy, which is the load-carrying material in a spaceborne instrument. As a part of the manufacturing process, the parts made of AA6061-T6 are subjected to a coating process at a temperature of about 220◦C for a time longer than 1 hour. This treatment modifies the mechanical properties of the alloy. To evaluate the consequences of this change for spaceborne components, mechanical testing, and numerical simulation were conducted. It was found that as a result of the coating process, the reduction in AA6061-T6 yield strength is about 16%, which entails a decrease in the margins of safety by 25% at its maximum.
EN
Since the implementation of repair processes by composite patch bonding, this process has consistently demonstrated high performance across various industrial sectors, especially in the fields of aeronautics, aerospace and civil engineering. Consequently, there are situations in which the riveting process becomes the sole solution, particularly when the structure is subjected to severe mechanical or thermo-mechanical stresses, since adhesives have low mechanical strength after aging. Each method has its own set of advantages and disadvantages. The current trend is to combine these two processes to minimise their drawbacks as much as possible. The objective of this work is to present an experimental study on the repair of an aluminium plate AL2024-T3 with a central circular notch using a patch of different nature (metal or composite), under tensile loading conditions. The repair composite considered is a carbon/epoxide. The results of the tensile tests showed that the repair by the combination of the two processes improves the mechanical strength of the damaged structure. A comparison of the results of the experimental curves obtained on riveted, bonded and hybrid assemblies has been taken into consideration.
EN
Based on the commercial aluminium alloy powder blend (Alumix 431D) metal matrix composites reinforced with particles of SiC as well as TiC were produced by conventional powder metallurgy technology and the effect of the type and amounts of reinforced particles on the selected properties and microstructure of sintered composites were investigated. In particular, the densification behaviour, the wear resistance and the corrosion resistance in 3.5% NaCl solution were identified. It was stated that both the type and the weight fraction of carbide used as particulate reinforcement have a great impact on the properties of aluminium alloy matrix composites. It was shown that the introduction of titanium carbide has a more favourable effect on the properties of sintered Alumix 431D matrix composites in comparison to silicon carbide and the optimum content of TiC in composite is 4 wt. % due to the highest hardness, wear resistance (wear rate of 2.865­­·10 ̄ ³ mm³/m) and simultaneously the best corrosion resistance (corrosion rate of 0.005 mm/year).
EN
The aim of the work was to analyze the method of preparing the aluminum surface in terms of the functional properties of glued joints with the use of one-component polyurethane adhesive. Six methods of surface treatment of EN AW-5251 aluminum alloy were tested. In addition, changes in the shear strength of adhesive joints after environmental exposure were determined. The best surface preparation processes were atmospheric plasma and anodizing.
PL
Celem pracy była analiza sposobu przygotowania powierzchni aluminium pod kątem właściwości użytkowych połączeń klejonych z zastosowaniem jednoskładnikowego kleju poliuretanowego. Zbadano sześć metod obróbki powierzchni stopu aluminium EN AW-5251. Ponadto określono zmiany wytrzymałości połączeń klejonych na ścinanie po ekspozycji środowiskowej. Najlepszym sposobem przygotowania powierzchni była plazma atmosferyczna i anodowanie.
EN
Purpose: In this study, an environmentally friendly metal matrix was prepared, and the influence of eggshell powder and CaCO3 particles on the tensile strength and hardness of recycled aluminium were assessed. Design/methodology/approach: A matrix made of recycled aluminium was employed. Calcium carbonate and eggshells served as the study's reinforcing materials. Separately, weight percentages of 2, 4, and 8% of eggshell and calcium carbonate were used. The samples were made by sand-casting. Findings: The results showed that both eggshell and calcium carbonate positively affect the hardness, yield, and ultimate tensile strength of recycled aluminium. The hardness values were improved as the percentage of the eggshell increased. The maximum hardness was achieved at 2% calcium carbonate. Similarly, the highest improvement of yield strength was for 2% CaCO3 addition, while the highest tensile strength was obtained at 8% eggshell addition. Research limitations/implications: To get better results, it would be desirable to use finer eggshells than those utilized in this study. Practical implications: Composites made with an aluminium matrix exhibit exceptional mechanical and physical characteristics. The most challenging obstacle to overcome is the cost of metal matrix composites. Eggshells are a by-product that could be employed as a lightweight, affordable form of reinforcement. One way to get rid of this by-product, improve composite characteristics, and lower the cost of aluminium composite is to use eggshells. Originality/value: A comparative investigation was carried out to determine the effects of adding agricultural by-product eggshell, and commercial CaCO3 reinforcement material on the characteristics of recycled aluminium matrix integrated 425 µm sized eggshell and CaCO3 separately as a reinforcement material to create a metal matrix that is beneficial to the environment.
8
Content available remote Separation technology of components of waste pharmaceutical blisters
EN
In this paper, the separation technology of components of waste pharmaceutical blisters and its adaptation to the industrial scale are described. It involved, among others, taking advantage of the phenomenon of difference in the density of the individual phases that were contained in the separation tank, i.e., the separating mixture, PVC plastics, and aluminium. As a result, the directions of movement of the separated blister components were opposite. All components of the separating mixture feature a similar surface tension (γ > 20 mN/m) which facilitates the penetration of the liquid between the blister component layers. After separation, the full-value products, i.e. polyvinyl chloride (PVC) and aluminium are obtained. The resulting products can be further processed and the entire technological process is a waste-free. PVC can be melted and processed into other products e.g. plastic components for the construction industry. Pure aluminium is a metal sought after and widely used in industry due to its low specific weight. An additional element supplementing the technology is the separation tank of our design in which the separation process of the blister components takes place. The advantage of the separation tank is that the separation process can be repeated many times with the same separating mixture until it is exhausted. Both separated blister components are directed to filtering followed by air drying without a mixing PVC plastic with aluminium.
EN
In this paper, the post-weld explosive hardening of a 5 mm AA7075-T651 plate welded via FSW was performed. To investigate the possibility of increasing FSW joint mechanical properties, the welded plate was explosively treated with four various explosive materials (ammonal, emulsion explosive, FOX-7, and PBX) in two different hardening systems. As part of the investigation, the observations of the surface and macrostructure of the treated plates were described. The obtained microhardness distribution allowed us to register the increase in hardness of the SZ up to 6%, but no increase in hardness of the LHZ was reported. In most cases, the influence of explosive treatment on the mechanical properties of the welded joint was disadvantageous as ultimate tensile strength and ductility were reduced. The only positive effect which was observed is the increase in the value of yield strength up to 27% corresponding to 77 MPa, achieved by explosive materials with detonation velocity below 3000 m/s.
EN
Turbulent filling of a mould is one of the ways to introduce extrinsic defects into the cast part that could deteriorate many properties of any casting. The turbulence can be easily eliminated by counter gravity casting. In gravity casting, tapered downsprue, tapered runner is needed such that the mould cavity is filled counter-gravity from the bottom which is the only best way to eliminate turbulence during filling. Tilt casting method also exists which has the potential to quiescently transfer the liquid into the mould cavity. In this work, gravity and tilt casting methods were used to evaluate the tensile properties of Nb grain refined 206 alloy. Three different Nb contents were investigated: 0.025, 0.05 and 0.1 wt% ratios and it was found that 0.05 wt% revealed the highest tensile properties. On the other hand, when the intrusion of surface folded oxides was eliminated during filling, it was found that mechanical properties were increased significantly, and particularly, the toughness was increased by two folds when tilt casting was applied compared to gravity casting.
EN
In this paper, the high-speed clinching named electromagnetic-driven clinching (EMDC) method was adopted and analyzed by experiment, numerical simulation and theoretical calculation. The deformation behavior and mechanical properties of 5052-O EMDC joints have been investigated. The result showed that the punch speed can reach 3 m/s, The maximum strain rate of the EMDC process can reach 6000 s−1. The EMDC process can be divided into deep drawing, interlocking, and unloading stages. The neck thickness tN changes mainly in deep drawing stage. The interlock value tU changes mainly in interlocking stage. The discharge voltage level can precisely control the formation of the joint. With the increase of the discharge voltage, the tN did not change significantly, while the tU increased and mechanical properties of the joint gradually improved. When the discharge voltage was 3.4 kV, the shear and tensile joint strength were 1571 N and 746 N, respectively. The simulation results and the theoretical calculations were in good agreement with the experimental results.
12
Content available remote Plasma welding of aluminum in an oxygen-free argon atmosphere
EN
Plasma welding is characterized by a high concentration of energy, which allows for high welding speed and leads to less distortion and residual stresses compared to conventional welding processes. Due to the local and controlled heat input, the process is suitable for sheet metal from ≈ 0.1 mm (micro plasma) up to ≈ 10 mm. In the case of aluminum and its alloys, the natural aluminum oxide layer on the metal surface limits the productivity of the plasma welding process. The electrically isolating and thermally insulating Al2O3 layer has a significantly higher melting point compared to the aluminum (Tm(Al2O3) = 2072 °C vs. Tm(Al) = 660 °C). The oxide layer hinders the formation of a stable arc and can even impede the joining formation. In order to remove the oxide layer and to produce quality welds with a DC process, it is necessary to weld with reverse polarity to use the principle of cathodic surface cleaning. However, this leads to increased electrode wear and increased penetration depth, which is not always desirable. In the study presented, the use of silane to reduce the oxygen content in the welding atmosphere as well as to remove the natural aluminum oxide layer on the metal surface was investigated. As previous studies have shown that the use of silane-doped plasma-gases is suitable for removing the superficial oxide layer on aluminum components, high-quality welded joints were expected. Quality welds with sufficient dilution were achieved using a transferred arc silane-doped helium plasma. In contrast, welding with an argon-silane mixture led to excessive pores formation. Additionally challenges to stabilize the arc process were identified and ramifications with respect to process optimization are discussed.
PL
Rok 2021 był rokiem wyjątkowym dla surowców, a ceny metali nieżelaznych notowanych na LME nie były wyjątkiem i wzrosły o 35%. Ceny miedzi i cyny osiągnęły najwyższy poziom w historii, podczas gdy ceny aluminium i cynku osiągnęły najwyższy poziom od 14 lat. W szczególności aluminium uzyskało drugie miejsce wśród głownych metali przemysłowych, co łatwo zrozumieć, patrząc na wydarzenia, jakie miały miejsce w Chinach, największym producencie i konsumencie aluminium.
EN
2021 was an exceptional year for raw materials, and prices of non-ferrous metals listed on the LME were no exception, gaining 35%. Copper and tin prices reached an all-time high, while aluminium and zinc prices reached their highest levels in 14 years. Aluminium in particular had the second best performance among the major industrial metals, a fact easily understood when looking at what happened in China, the largest producer and consumer of aluminium.
EN
5005A series aluminum samples were passivated to obtain a conversion coating based on Cr(III) compounds. It was shown that the corrosion resistance of galvanized aluminum in a bath containing both zirconium and cobalt compounds, measured in a 0.05 M NaCl solution, slightly increased compared to the corrosion resistance of aluminum as delivered, i.e. without conversion coating. In the case of galvanic treatment of aluminum in baths containing separately cobalt or zirconium compounds, a significant increase in corrosion resistance was achieved in relation to aluminum in the delivered condition. SEM analysis showed that in the presence of the simultaneous addition of zirconium and cobalt compounds, the most developed surface was created compared to the addition of only zirconium, where bright spheroidal precipitates occur locally. EDS analysis showed the presence of : C, O, Mg, Al and Si, small amounts of Cr, Zr, F on the surface of the aluminum covered with the Cr + Zr + HF conversion coating. During measurements with the use of the linear polarization resistance (LPR) technique, the best anti-corrosion properties were demonstrated by the samples that were passivated in a Cr(III) solution with the addition of Zr compound and HF and in a Cr(III) solution with the addition of Co compound and HF.
PL
Próbki aluminium serii 5005A poddano procesowi pasywacji z wytworzeniem powłoki konwersyjnej na bazie związków Cr(III). Wykazano, że odporność korozyjna aluminium poddanego obróbce galwanicznej w kąpieli zawierającej jednocześnie związki cyrkonu i kobaltu, mierzona w 0,05 M roztworze NaCl, nieznacznie wzrosła w stosunku do odporności korozyjnej aluminium w stanie dostarczenia, tzn. bez powłoki konwersyjnej. W przypadku obróbki galwanicznej aluminium w kąpielach, które zawierały osobno związki kobaltu lub cyrkonu, uzyskano wyraźny wzrost odporności korozyjnej w stosunku do aluminium w stanie dostarczenia. Analiza SEM wykazała, że w obecności jednocześnie dodatku cyrkonu i kobaltu powstała najbardziej rozwinięta powierzchnia. W przypadku zastosowania tylko dodatku cyrkonu jasne wytrącenia sferoidalne występują lokalnie. Analiza EDS wykazała obecność C, O, Mg, Al i Si, niewielkich ilości Cr, Zr, F na powierzchni aluminium pokrytego powłoką konwersyjną Cr + Zr + HF. Podczas pomiarów techniką liniowego oporu polaryzacji (LPR) najlepsze właściwości antykorozyjne wykazały próbki poddane pasywacji w roztworze Cr(III) z dodatkiem związków Zr i HF oraz w roztworze Cr(III) z dodatkiem związków Co i HF.
EN
Electron Backscatter Diffraction (EBSD) is a scanning electron microscope (SEM) based technique, which enables a sample’s microstructure to be analysed, visualised and quantified. The EBSD method together with associated techniques provides useful information how to interpret the obtained results. Microstructure is the internal structure of a material investigated on the microscopic scale. It is of interest because a material’s internal features (i.e. structure) influences its properties and behaviour. The EBSD method has become the primary tool for characterising microstructures in most metals, alloys, composites and ceramics. The range of applications is numerous, from rapid measurement of grain size and texture in metal sheets, welded joints etc. Many of these materials are relatively simple to analyse using EBSD, but advanced tools such as high-resolution pattern correlation approaches can be applied to improve our understanding of these materials [1]. This method has been applied to investigace the structure of Al ‒ austenitic CrNi steel. Only partial results as for the EBSD method will be given here.
PL
Detektor EBSD (dyfrakcja elektronów wstecznie rozproszonych) zainstalowany w skaningowym mikroskopie elektronowym (SEM) umożliwia analizę, wizualizację i ocenę ilościową mikrostruktury próbki. Metoda EBSD wraz z powiązanymi technikami dostarcza przydatnych informacji, umożliwiających interpretację wyników. Mikrostruktura to wewnętrzna struktura materiału badana w skali mikroskopowej. Jest ona interesująca, ponieważ wewnętrzne cechy materiału (tj. struktura) determinują jego właściwości. Metoda EBSD stała się podstawowym narzędziem do charakteryzowania mikrostruktur w większości metali, stopów, kompozytów i ceramiki. Zakres zastosowań jest szeroki, obejmujący m.in. szybki pomiaru wielkości ziarna i tekstury w blachach, złączach spawanych itp. Wiele z tych materiałów można stosunkowołatwo poddać analizie EBSD, ale zaawansowane narzędzia, takie jak metody operate o analizę obrazu, można zastosować w celu lepszego poznania struktury tych materiałów [1]. Metodę tę zastosowano do badania struktury bimetalu typu aluminium-stal austenityczna CrNi. W tym miejscu omówione jedynie częściowe wyniki analizy EBSD.
EN
Light alloys are widely used in industry and everyday life due to their high physical and mechanical properties, wear and corrosion resistance, as well as low cost. In this regard, the use of light alloys as a basis for composite materials is both justified and expedient. The potential of these materials has not been fully used to this day, despite the growing interest in metal matrix composites and extensive investigations aimed at the development of production technology and the introduction of advanced systems based on light matrices. The article presents a short review of the analysis of the main components of the technology of cast composite materials based on light alloys of aluminum and magnesium reinforced by particles. Particular attention is paid to the choice of the matrix alloy, the type, size and amount of reinforcing particles introduced into it, as well as the thermal-time and kinetic parameters of the process.
EN
Purpose: This research aims to analyse the influence of blanking clearance size on the burr development for mild steel sheet, brass and aluminium. The main reason for this research is estimating the burr size on blank parts. It is still significant since the quality of the products is determined by evaluating the amount of allowable burr in the parts. Design/methodology/approach: For the blanking process on the 3.00 mm thick sheets, various sizes of blanking clearance for a 20 mm diameter of the die opening are employed, as is the technique for obtaining the parts. Then the height of the burr on each product was measured using a micrometre and toolmaker microscope. The height of burr for each size of blanking clearance have been recorded and compared using a graph. Comparison made to identify which measure of blanking clearance and which type of material will produce a small size of burr. Findings: For mild steel, brass, and aluminium, blanking clearance 0.15 mm produced burr heights of 0.088 mm, 0.015 mm, and 0.024 mm, and blanking clearance 0.13 mm produced bur heights of 0.192 mm, 0.055 mm, and 0.046 mm, respectively. The brass had a lower burr height than mild steel and aluminium, according to the results. More significant blanking clearance (0.15 mm) produced a smaller size of burr compared to a smaller blanking clearance (0.13 mm). Practical implications: This study focuses on burr height rather than the wear of the punch and die cutting edge; burr height can affect punch and die sharpness. It also can guide practitioners in estimating blanking clearance and the burr height of mild steel, brass and aluminium. Originality/value: This paper demonstrates that the gap between the punch and die influences the burr height. The material strength also affects the burr height, with a high tensile strength resulting in a larger burr.
EN
This work aims to join sheets of carbon steel to aluminum alloy AA6061. A lap joint arrangement was used with a joint lap area of dimensions *25 25 mm . The joining procedure was carried out using a rotating tool of 10 mm shoulder diameter. Three process parameters, with three levels for each parameter, were selected to investigate their effects on joints quality. The parameter’s levels for each experiment were designed using the design of the experiment method (DOE). The results indicated that the two materials were joined by a mechanical interlock at an interface line, without formation of intermetallic compounds. The shear force of the joint reached an ultimate value of .4 82kN . The shear force of the joint improved by increasing plunging depth of the tool. Samples of minimum shear force value failed by a pull-outing aluminum metal from the carbon steel specimen. Samples of higher shear force value exhibited a shear mode of fracture. Increasing the rotating speed and decreasing pre-heating increased the process temperature.
EN
The resistance spot welding (RSW) method was used to join aluminum alloy AA 1050 and copper alloy UNS C50100 sheets. Mechanical properties of the joints were examined. The influence of welding process parameters on tensile shear force of the joints was discussed. The design of experiments (DOE) method was used to analyze the influence of welding parameters on the mechanical properties of the joints. Three RSW parameters were used: welding current, squeeze time, and welding time. The results showed that the joint shear stress increased with increasing the welding current until a value of 12000 Amp. Then the shear stress decreased. The tensile shear stress increased with increasing the welding and squeeze time. As a consequence, it can be possible to weld copper with aluminum by RSW.
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