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EN
Friction welding is one of the most economical process of joining solid-state materials. This technique allows to weld similar and dissimilar materials in a very short time. Friction welding of metal with composites gives new possibilities of application, due to the fact that materials have different physical and mechanical properties. In the study, aluminum alloy 44200 was friction welded to Al/Al2O3 composite. In addition, the following inspections were performed: optical microscopy, microhardness measurements and also tensile strength for all joints produced by friction welding. All of the studies were performed to evaluate the quality of connection between the 44200 alloy and the composites on the aluminum alloy matrix reinforced with ceramic phase of Al/Al2O3.
PL
Zgrzewanie tarciowe to jedna z bardziej ekonomicznych metod trwałego łączenia materiałów w stanie stałym. Metoda ta umożliwia wykonywanie złączy zarówno jednoimiennych, jak i różnoimiennych w bardzo krótkim czasie. Zaletą zgrzewania tarciowego jest możliwość uzyskania złączy o wysokiej jakości. Zgrzewanie tarciowe kompozytów z metalami, stwarza nowe możliwości aplikacji, z uwagi na fakt, że oba materiały posiadają różne właściwości fizyczne oraz mechaniczne. W pracy przeprowadzono próby spajania stopu aluminium EN-AC-44200 z kompozytami Al/Al2O3. W opracowaniu przeprowadzono następujące badania złączy stop aluminium-kompozyt uzyskanych metodą zgrzewania tarciowego: mikroskopowe, twardości, mechaniczne (pomiar wytrzymałości na rozciąganie). Wykonane badania miały na celu ocenę jakości połączenia pomiędzy stopem 44200, a kompozytami na osnowie stopu aluminium wzmacnianymi fazą ceramiczną Al/Al2O3.
EN
The article presents the analysis of the wetting ability by Epidian 5 epoxy resin with hardener Z1 of EN AW-2017A aluminum alloy sheets. The material sheets were subjected to the selected methods of processing in order to obtain different parameters of the geometric development of the surface. The energy state of the surface layer was examined on the prepared surfaces, taking the polar and non-polar free surface energy components into account. On the basis of the obtained results, wetting envelopes were determined, which represent the limit value of the surface energy components of the wetting liquid, ensuring good wetting. As part of the research, an analysis of the possibilities of achieving maximum adhesion work between a solid and a liquid in the event of changes in the contact angle was also conducted. This analysis allows one to determine how the parameters of the test adhesive deviate from the ideal, i.e. those for which the surface tension at the interface reaches the minimum value. Based on the results of the analysis, a summary was prepared, showing the ability of the adhesive to wet surfaces with different roughness parameters.
PL
W artykule przedstawiono analizę zdolności zwilżania przez klej Epidian 5 z utwardzaczem Z1 powierzchni blach ze stopu aluminium EN AW-2017A. Blachy poddano wybranym sposobom obróbki w celu uzyskania odmiennych parametrów rozwinięcia geometrycznego powierzchni. Na tak przygotowanych powierzchniach przeprowadzono badania stanu energetycznego warstwy wierzchniej z uwzględnieniem składowej polarnej i niepolarnej swobodnej energii powierzchniowej. Na podstawie otrzymanych wyników wyznaczono krzywe zwilżania, które przedstawiają graniczną wartość składowych swobodnej energii powierzchniowej cieczy zwilżającej, zapewniające uzyskanie dobrego zwilżania. W ramach badań przeprowadzono również analizę możliwości osiągnięcia maksymalnej pracy adhezji między ciałem stałym, a cieczą w przypadku zmian kąta zwilżania. Analiza ta pozwoliła na określenie na ile parametry badanego kleju odbiegają od idealnych, czyli takich, dla których napięcie powierzchniowe na granicy faz osiąga wartość minimalną. W oparciu o uzyskane wyniki analiz dokonano zestawienia obrazującego zdolność kleju do zwilżania powierzchni o różnych parametrach chropowatości.
EN
The use of cast aluminium has still increased, so have the mechanical property requirements. By casting and also in other metallurgical processes, the inclusions enter to the molten aluminium alloy and it exhibits poor ductility or toughness. It can cause a variety of problems in the manufacture of aluminium alloy castings. Therefore, the purification of the molten aluminium alloy is one of the most important processes for improving the quality of Al-products. Filters have been used for many years in order to improve the quality of castings. The inclusions in molten secondary AlSi7Mg0.3 cast were removed using depth filtration by ceramic foam filters of 20 ppi porosity. Were used 4 types of ceramic filters in 2 thicknesses (15 and 22 mm); Brinell hardness and porosity were measured. Quality of microstructure (occurrence of oxidic particles and larger non-metallic inclusions) was observed. Experimental results show that the insertion of ceramic filters into the inlet system has contributed primarily to a decrease in porosity. On the microstructure, the inclusion of filters was not significantly reflected.
EN
Ultrasonic treatment is known to be efficient for aluminium melt degassing with the additional benefits of being both economical and environment friendly. This paper describes the effect of ultrasonic degassing on the preparation of an AlSi9Cu3(Fe) alloy for High Pressure Die Casting (HPDC). The degassing efficiency was assessed in terms of the indirect evaluation of the melt, by means of the reduced pressure test and the porosity evaluation of the cast parts. Additionally, the corresponding hydrogen content was estimated with an experimental equation reported in the literature. Ultrasonic degassing shows greater efficiency in terms of hydrogen removal from the melt than conventional N2 + Ar lance bubbling. Components produced by HPDC without degassing, with ultrasonic degassing and with lance degassing, were analysed by computed tomography and by metallography. The results show that the components produced by HPDC after ultrasonic degassing have a similar porosity level to components degassed with conventional lance bubbling, both showing an important improvement over components produced without degassing treatment. Hardness values were similar for all different treatment conditions and well over the minimum value established for the alloy by the corresponding standard.
EN
Purpose: The aim of the proposed research is to investigate the influence of temperature and duration of isothermal melt processing on structural characteristics of castings in connection with technological background of charge metal. Design/methodology/approach: Ferrous and non-ferrous alloys were obtained by remelting a charge with a dispersion-structured structure (which was ensured by high- speed crystallization). Remelting was carried out at different temperatures of overheating of the melt over the liquidus with different isothermal exposure at these temperatures. Experimental castings were crystallized under normal conditions. It was studied a change of structure formation and mechanical characteristics depending on the temperature and duration of thermal treatment of the melt before crystallization. Findings: It is established that isothermal treatment of the melt at the overheating of the liquid metal above a certain equilibrium temperature of the micro-inhomogeneous melt (Te) causes a gradual loss of hereditary characteristics of the original charge metal, increase of the chemical homogeneity of the melt and the formation of crystallization and formation a corresponding change in the mechanical properties of castings. Research limitations/implications: The results can be complemented by studies of the effect of thermal treatment in the temperature range of crystallization. Practical implications: The results can be used to select the optimal heat treatment during remelting and, accordingly, the mechanical properties of the resulting casting. Originality/value: The obtained results testify to the predominant influence of temperature on the dispersion of the cast structure of steels, given the duration of technological operations of preparation and casting of steels in the manufacture of castings in industrial conditions.
EN
The paper deals with the effect of heating of various prepared batch materials into semisolid state with subsequent solidification of the cast under pressure. The investigated material was a subeutectic aluminium alloy AlSi7Mg0.3. The heating temperature to the semisolid was chosen at 50% liquid phase. The used material was prepared in a variety of ways: heat treatment, inoculation and by squeeze casting. Also the influence of the initial state of material on inheritance of mechanical properties and microstructure was observed. The pressure was 100 MPa. Effect on the resulting casting structure, alpha phase distribution and eutectic silicon was observed. By using semisolid squeeze casting process the mechanical properties and microstructures of the casts has changed. The final microstructure of the casts is very similar to the microstructure that can be reached by technology of thixocasting. The mechanical properties by using semisolid squeeze casting has been increased except the heat treated material.
EN
The Comparative Analysis of the Inclusion Removal Efficiency of Different Fluxes
8
Content available Influence of Zr on AlSi9Cu1Mg Alloy Cast in Ceramic
EN
The article focuses on the analysis of the effect of Zr on the properties of the aluminium alloy AlSi9Cu1Mg. The effect of Zr was evaluated depending on the change in mechanical properties and heat resistance during a gradual addition of Zr with an increase of 0.05 wt. % Zr. Half of the cast experimental samples from each variant were heat treated by precipitation hardening T6 (hereinafter HT). The measured values in both states indicate an improvement of the mechanical properties, especially in the experimental variants with a content of Zr ≥ 0.20 wt. %. In the evaluation of Rm, the most significant improvement occurred in the experimental variant with an addition of Zr 0.25 wt. % after HT and E in the experimental variant with addition of Zr 0.20 wt. % after HT. Thus, a difference was found from the results of the authors defining the positive effect of Zr, in particular at 0.15 wt. %. When evaluating the microstructure of the AlSi9Cu1Mg alloy after Zr alloying, Zr phases are already eliminated with the addition of Zr 0.10 wt. %. Especially at higher levels of Zr ≥ 0.20 wt. %, long needle phases with slightly cleaved morphology are visible in the metal matrix. It can be stated that a negative manifestation of Zr alloying is expressed by an increase in gassing of experimental alloys, especially in variants with a content of Zr ≥ 0.15 wt. %. Experimental samples were cast into ceramic moulds. The development of an experimental alloy AlSi9Cu1Mg alloyed with Zr would allow the production of a more sophisticated material applicable to thin-walled Al castings capable of operating at higher temperature loads.
EN
The article presents investigation results of the effect of sand fluidization on the structure and mechanical properties of AlSi9 aluminum alloy. Castings were made by lost foam casting process with sand fluidization in mold at the stages of their solidification and cooling. Sand fluidization was achieved by blowing sand bed with compressed air in a foundry container. The metallographic study was carrying out on samples cut from different sections of the castings. Mechanical properties were determined on specimens made from cast samples. Microstructural analysis showed that sand fluidization increases the cooling rate, as a result, the main microstructural components of the alloy – SDAS, eutectic silicon and needles of the rich-iron phase – decrease. Moreover, in different sections of the casting structure is more uniform. With an increasing the air flow rate, a greater refinement of the structure is observed. Through the use of sand fluidization, the mechanical properties of LFC aluminum alloys increase to the level of gravity die castings.
EN
With the aid of eutectic modification treatment, the precipitation of coarse lamellar eutectic silicon can be suspended during the solidification of aluminum-silicon alloys, thereby the formation of fine-grained, fibrous eutectic Si can be promoted by the addition of small amounts of modifying elements, such as Sr, to the liquid alloy. The effectiveness of this technique is, however, highly dependent on many technological factors, and the degree of modification can be lowered during the various stages of melt preparation due to the oxidation of the Sr-content of the melt. During our research, we investigated the effect of rotary degassing melt treatments coupled with the addition of three different fluxes on the degree of modification of an Al-Si-Mg-Cu casting alloy. It was also studied, that whether additional Sr alloying made before and during the melt treatments can compensate the Sr fading with time. The degree of eutectic modification was characterized by thermal analysis (TA) and the microscopic investigation of TA specimens. It was found, that by using one of the three fluxes, and by adding Sr master alloy rods before the melt treatments, better modification levels could be achieved. It was also found that the measurement of Sr-concentration by optical emission spectroscopy alone cannot be used for controlling the level of eutectic modification.
EN
The objective of this study was to deposit directly chromium with diamond nanoparticles (ND) on aluminum alloys and investigate the coating surface. The chromium coatings on aluminum alloys were obtained by electrochemical deposition. The coatings were doped with ND. The diamond nanoparticles were obtained by detonation synthesis. Chromium coatings were deposited on aluminum alloys with a silicon content of 7 % and 10 %. The ND concentration in the electrolyte was 25 g/l. The surface analysis was performed by means of Atomic force microscopy. The surface of the coating of chromium with ND on Al10Si is twice more even than that on Al7Si. The microstructure and microhardness were examined with a metallographic microscope and a microhardness tester. The microhardness of the coated samples is 9163 MPa compared to 893 MPa of uncoated aluminum samples. The thickness of the chromium coatings doped with diamond nanoparticles is between 45 – 55 μm. The coatings are dense, continuous and uniform with good adhesion to the substrate material.
EN
An experimental method of evaluating the fatigue behavior of alloys in different particle environments was designed, and the effects of four kinds of particles (i.e., graphite, CaO, Al2O3, and MnO2) on the crack propagating behavior of 7N01-T6 behaviour alloys were investigated. The results show that the particles deposited on the crack surface exert significant influence on the fatigue crack propagation behavior thereof. This influence strongly depends on the elastic moduli of the particles (Ep). As Ep is less than that of aluminium alloy (EAl), the particle accelerates the fatigue-crack-growth rate (FCGR) in the alloys due to the lubrication of the particles on the mating fracture surfaces. When the difference between Ep and EAl is small, the particle effect on the FCGRs of the alloys is small due to the counteraction between the decrease in friction and the promotion on the crack closure of mating fracture surfaces. When Ep is greater than EAl, the particles slow down the FCGRs of the alloys on account of significant crack closure effect. As Ep is much greater than EAl, the particles increase the FCGRs because of the increasing stress concentration at the crack tip.
13
Content available remote Evolution of Goss texture in an Al–Cu–Mg alloy during cold rolling
EN
Evolution of Goss texture in an Al–Cu–Mg alloy during cold rolling was investigated by three-dimensional orientation distribution functions, electron back-scattered diffraction and transmission electron microscopy. The results showed that with increasing reduction from 23.7 to 80%, Goss textures gradually transformed into Brass texture through the activation of sole {111}<110> slip systems. When rolling reduction further increased from 80 to 86.3%, Goss texture rather than Brass started to rotate towards Copper and S components. The formation of Copper and S textures at these high reductions was attributed to the activation of {110}<110> and {001}<110> non-octahedral slip systems.
EN
Refill friction stir spot welding (RFSSW) is a solid state joining technology that has the potential to replace processes such as the open-air fusion bonding technique and rivet technology in aerospace applications. Selection of proper RFSSW parameters is a crucial task which is important to ensure the mechanical strength of the joint. The aim of this paper is to undertake numerical modelling of the RFSSW process to understand the physics of the welding process, which involves large deformations, complex contact conditions and steep temperature gradients. Three-dimensional fully coupled thermo-mechanical models of RFSSW joints between Alclad 7075-T6 aluminium alloy sheets have been built in the finite-element-based program Simufact Forming. The simulation results included the temperature distribution and the stress and strain distributions in the overlap joint. The results of numerical computations have been compared with experimental ones. The numerical model was able to predict the mechanics of material flow during the joining of sheets of Alclad aluminium alloys using RFSSW. The predictions of the temperature gradient in the weld zone were in good agreement with the temperature measured experimentally. The numerical models that have been built are capable of simulating RFSSW to reduce the number of experiments required to set optimal welding parameters.
EN
This paper deals with different types of artificial ageing and its effect upon the mechanical properties of an aluminium alloy. For the purposes of this research, the EN AW 2017 alloy was subjected to different types of heat treatment. These samples were subjected to different analyses. The results of hardness measurements (HB and HV) revealed the highest values of the non‑heat treated sample. The static tensile stress test proved the highest ductility of the heat treated samples. Overall, the best were revealed for the sample artificially aged at 160°C.
EN
In the process of plastic bending of thin-walled profiles, there is a significant deformation of the cross-section, which has a very significant impact on the course and effects of the shaping process construction products. In this paper, the experimental, analytical as well as numerical analyses of the box profile bending process enabled to establish the relationships determining the dependence of the cross-sectional form and bending moment on the bending curvature. The following paper discusses pure bending moment and the cross-sectional deformation of 21.5×21.5×1.8 mm and 25×25×2.5 mm square tubes made of the 6060 aluminium alloy. Satisfactory agreement of the experimental results and numerical calculations was obtained for the values of horizontal and vertical wall deflection, as well as for the experimental, calculated and numerical bending moment characteristics.
EN
The paper presents the results pertaining to an analysis on the influence of technological parameters of pneumatic shot peening technology on the selected properties of a surface layer of butt joints made with Friction stir weld‑ ing (FSW) method. Butt joints made of two 2024‑T3 aluminum alloy sheets with the thickness of 1 mm were shot peened with glass beads. The experiments were carried out according to the statistical 3‑level completed plan PS/DC 32 . The technological parameters were changed in the range: pressure p = 0.4–0.6 MPa and peening time t = 1–3 min. As a result of the conducted research, adequate equations describing the effect of the analyzed parameters on the surface roughness were obtained. Shot peening with glass beads significantly reduced the sur‑ face roughness from Ra = 5.2 µm to Ra = 1.42 µm. This treatment provides high compressive residual stresses and the increase of the surface layer hardness. The results show that shot peening is a highly efficient and cost‑effective mechanical treatment used for improving the mechanical properties of the butt joints made with the FSW method.
18
EN
Adhesive joints are widely used in various industries to join different materials. They always have to meet specific requirements for joint strength or durability. The article presents the results of research on the problem of joining elements made of aluminum alloy and polymer composite material present in the railway industry. The tested adhesive joints combine EN AW-5754 aluminum alloy (AlMg3) with a polyester-glass laminate. Three types of adhesives were used in the tests: epoxy, methacrylic and cyanoacrylate. Various methods of preparing the base surface and the bonded elements were used. The adhesive bonded surfaces were prepared using sandblasting and degreasing, grinding and degreasing as well as only degreasing. The research used a composite made with the use of two different technologies: contact molding and vacuum molding. Comparative tests were also carried out by making adhesive joints of two aluminum surfaces. The aim of the research was to propose a gluing technology to achieve min 15 MPa of the pull-off strength. The tests show that the required strength of the joint can be achieved only for an adhesive joint based on epoxy or methacrylic adhesive when preparing the surface of the base material by sanding and degreasing, grinding and degreasing, or even only degreasing.
PL
Połączenia klejowe są szeroko stosowane w różnych branżach przemysłowych do łączenia materiałów o odmiennych właściwościach mechanicznych i użytkowych. Zawsze muszą one spełniać określone wymagania w zakresie wytrzymałości czy też trwałości. W artykule zaprezentowano wyniki badań dotyczące problemu łączenia elementów wykonanych ze stopu aluminium i polimerowego materiału kompozytowego występującego w branży kolejowej. Badano połączenia adhezyjne występujące pomiędzy stopem aluminium EN AW-5754 (AlMg3) a laminatem poliestrowo-szklanym. W badaniach zastosowano trzy rodzaje klejów: epoksydowy, metakrylowy i cyjanoakrylowy. Zastosowano również różne sposoby przygotowania powierzchni do klejenia. Powierzchnie klejone przygotowano stosując piaskowanie i odtłuszczanie, szlifowanie i odtłuszczanie oraz odtłuszczanie. W badaniach zastosowano kompozyt wykonany dwoma różnymi technologiami: tzw. technologią na mokro (contact molding) oraz z wykorzystaniem worka próżniowego (vacuum molding). Przeprowadzono również badania porównawcze wykonując połączenia klejowe dwóch powierzchni aluminiowych. Celem badań było zaproponowanie technologii wykonania połączenia tak aby wytrzymałość doraźna połączeń na odrywanie była nie mniejsza niż 15 MPa. Z przeprowadzonych badań wynika, że przyjętą wytrzymałość połączenia można osiągnąć wykorzystując klej epoksydowy lub metakrylowy po przygotowaniu powierzchni materiału bazowego poprzez piaskowanie i odtłuszczanie, szlifowanie i odtłuszczanie lub odtłuszczanie.
EN
Designers have a major interest about fatigue properties of materials used in transport industry. Each component in transport works under alternating stress. From this point of view the fatigue properties are important for single parts lifetime resulting into safety of whole components as cars and airplanes what leads to safety on the roads or air and have influence on human life as well. Therefore this paper deals with fatigue properties of wrought Inconel alloy IN 718 and aluminum cast alloy AlSi9Cu3. Both materials were put on fatigue push – pull test, but Ni – based IN 718 alloy at frequency of loading around 20 000 kHz (High Frequency High Cycles Fatigue) and aluminum alloy AlSi9Cu3 at frequency of loading around 80 Hz (Low Frequency High Cycles Fatigue). These parameters were chosen with respect of usage such materials for production of components used in transport industry applications. Results after fatigue tests are presented as Wohler curve. For prediction of source of fracture the SEM fractography analysis of fatigue fracture surfaces was made.
20
Content available remote Gazy osłonowe do spawania łukowego aluminium i jego stopów
PL
W artykule omówiono rodzaj i skład gazów używanych podczas spawania aluminium i jego stopów z zastosowaniem metod: TIG, MIG i LBW, jak również opisano wpływ tych gazów na proces spawania i jakość złączy spawanych.
EN
The type and composition of gases used in TIG, MIG and LBW welding of aluminium and its alloys are discussed, as well as the influence of shielding gases on the welding process and the quality of welded joints are described.
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