ANALYSIS OF THE PROPERTIES OF AW2099 ALUMINIUM-LITHIUM ALLOY WELDED BY LASER BEAM WITH AW5087 ALUMINIUM-MAGNESIUM FILLER MATERIAL

EN AW2099 aluminium lithium alloy, 2.0mm in thickness, was used as an experimental material. EN AW2099 belongs to the 3rd generation of aluminium lithium alloys. The third generation was developed to improve the disadvantages of the previous generation, such as anisotropy in mechanical properties, low fracture toughness, corrosion resistance and resistance to fatigue crack growth, as well. Aluminium magnesium 5087 filler wire with a diameter of 1.2mm was used for the welding. Crack free weld joints were produced after an optimization of welding parameters. The microstructure of weld metal and mechanical properties of weld joints were investigated. Equiaxed zone (EQZ) was observed at the fusion boundary. The character of grains changed in the direction towards the weld centre, from the columnar dendrite zone to equiaxed dendrite zone in the weld centre. The microstructure of the weld metal matrix consisted of -aluminium. Alloying elements enrichment was found at the inter-dendritic areas, namely copper and magnesium. The microhardness decrease in the weld metal due to a dissolution of strengthening precipitates was measured. The microhardness was slightly higher in comparison to a weld produced by a laser welding without a filler material. The tensile strength of the weld joint reached around 67% of the base material’s strength and the fracture occurred in the weld metal

ANALYSIS OF THE PROPERTIES OF AW2099 ALUMINIUMLITHIUM ALLOY WELDED BY LASER BEAM WITH AW5087 ALUMINIUMMAGNESIUM FILLER MATERIAL

EN AW2099 aluminium lithium alloy, 2.0mm in thickness, was used as an experimental material. EN AW2099 belongs to the 3rd generation of aluminium lithium alloys. The third generation was developed to improve the disadvantages of the previous generation, such as anisotropy in mechanical properties, low fracture toughness, corrosion resistance and resistance to fatigue crack growth, as well. Aluminium magnesium 5087 filler wire with a diameter of 1.2mm was used for the welding. Crack free weld joints were produced after an optimization of welding parameters. The microstructure of weld metal and mechanical properties of weld joints were investigated. Equiaxed zone (EQZ) was observed at the fusion boundary. The character of grains changed in the direction towards the weld centre, from the columnar dendrite zone to equiaxed dendrite zone in the weld centre. The microstructure of the weld metal matrix consisted of -aluminium. Alloying elements enrichment was found at the inter-dendritic areas, namely copper and magnesium. The microhardness decrease in the weld metal due to a dissolution of strengthening precipitates was measured. The microhardness was slightly higher in comparison to a weld produced by a laser welding without a filler material. The tensile strength of the weld joint reached around 67% of the base material’s strength and the fracture occurred in the weld metal

Resistance Spot Welding of dissimilar Steels

This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA). Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials

Influence of the pyrotechnic igniter composition aging on explosion parameters of dispersed dusts

A commercially available pyrotechnic igniter was used according to the EN 14034 and ASTM E1226a Standards to study the explosiveness of dispersed dusts. Its pyrotechnic composition consists of 1.2 g of zirconium (40% wt.), barium peroxide (30% wt.) and barium nitrate (30% wt.). The energy released during the combustion of that amount of composition is 5 kJ. The article investigates the influence of aging of the pyrotechnic composition in the igniter on its initiation parameters. In the study, igniters of different years from date of manufacture were used: Igniter 1, manufactured in 2021 (less than 1 year from date of manufacture), and Igniter 2 (more than 2 years from date of manufacture). The study was performed in the KV 150M2 explosion chamber with a volume of 365 L and the 20 L sphere chamber with a volume of 20 L. A standard sample of Lycopodium clavatum was used in the KV 150M2 explosion chamber. Magnesium and benzoic acid were used as the samples in the 20 L sphere explosion chamber. The experiment showed that the explosion pressure P-max of the igniter with more than 2 years from date of manufacture decreased by up to 10%, while the value of the explosion constant K-st decreased by up to 40%. The attained results proved that aging of igniters affects their explosion parameters and measurement accuracy.Web of Science1122art. no. 1072

Microstructure, mechanical and tribological properties of advanced layered WN/MeN (Me = Zr, Cr, Mo, Nb) nanocomposite coatings

Due to the increased demands for drilling and cutting tools working at extreme machining conditions, protective coatings are extensively utilized to prolong the tool life and eliminate the need for lubricants. The present work reports on the effect of a second MeN (Me = Zr, Cr, Mo, Nb) layer in WN-based nanocomposite multilayers on microstructure, phase composition, and mechanical and tribological properties. The WN/MoN multilayers have not been studied yet, and cathodic-arc physical vapor deposition (CA-PVD) has been used to fabricate studied coating systems for the first time. Moreover, first-principles calculations were performed to gain more insight into the properties of deposited multilayers. Two types of coating microstructure with different kinds of lattices were observed: (i) face-centered cubic (fcc) on fcc-W2N (WN/CrN and WN/ZrN) and (ii) a combination of hexagonal and fcc on fcc-W2N (WN/MoN and WN/NbN). Among the four studied systems, the WN/NbN had superior properties: the lowest specific wear rate (1.7 × 10^-6 mm^3/Nm) and high hardness (36 GPa) and plasticity index H/E (0.93). Low surface roughness, high elastic strain to failure, Nb2O5 and WO3 tribofilms forming during sliding, ductile behavior of NbN, and nanocomposite structure contributed to high tribological performance. The results indicated the suitability of WN/NbN as a protective coating operating in challenging conditions

Badanie właściwości bimetali Cu-Al zgrzewanych wybuchowo

Przedstawiono wyniki zgrzewania wybuchowego miedzi C10200 ze stopem aluminiowym AW 5083. Płytka wykonana z miedzi C10200 była elementem napędzanym. Zgrzewanie wybuchowe prowadzono równolegle na dwóch stanowiskach. Otrzymane bimetale charakteryzowały się regularną falistą powierzchnią łączenia. Badania warstwy związku międzymetalicznego, w obszarze połączenia bimetalicznego, przeprowadzono po upływie 12 miesięcy, jednakże bez wyżarzania. Analiza EDX wykazała, że warstwa łącząca składa się z związku międzymetalicznego CuAl. Mikrotwardość w obszarze łączenie wzrasta zarówno w wyniku obecności związku międzymetalicznego, jak i przeprowadzonego zgrzewania

Wpływ obróbki cieplnej na właściwości złączy Cu-Al zgrzewanych wybuchowo

Explosive welding of copper C10200 to aluminium alloy AW 5083 was performed. C10200 was proposed as a flyer plate due to its suitable plastic properties. A parallel layout of welded metals was selected to attain a more stable welding process. Welding parameters and conditions were determined. The surfaces of both materials were mechanically machined and degreased prior to welding which was performed using Semtex S30. The bimetals were characterized by a regular wavy interface. The aim of the research was to establish the influence of heat treatment on both the structure and microhardness at the interface of the explosively welded bimetal Al-Cu. Heat treatment was performed at 250, 300 and 350 °C over 2, 3 and 4 h. After heat treatment, an increase in Inter Metallic Compounds (IMC) was observed, proportional to the increasing temperature. An analysis of chemical composition carried out by EPMA (Electron Probe Micro Analysis) confirmed the presence of Inter Metallic Phases (IMP) such as θ (Al2Cu), η2 (Al2Cu), ξ2 (Al3Cu4), δ (Al2Cu3), γ1 (A14Cu9). The microhardness decreased after the heat treatment in the bimetal but significantly increased at the interface as a consequence of IMC formation.Wykonano zgrzewanie wybuchowe stopu aluminium miedź C10200 i AW 5083. C10200 został zaproponowany jako płyta napędzana ze względu na jego odpowiednie właściwości plastyczne. Wybrano równoległy układ zgrzewanych metali, aby uzyskać bardziej stabilny proces łączenia. Określono parametry i warunki łączenia. Powierzchnie obu materiałów zostały poddane obróbce mechanicznej i odtłuszczeniu przed zgrzewaniem wykonanym przy użyciu Semtex S30. Bimetale charakteryzowały się regularną falistą powierzchnią styku. Celem badań było określenie wpływu obróbki cieplnej zarówno na strukturę, jak i mikrotwardość na granicy faz bimetalu Al-Cu zgrzewanego wybuchowo. Obróbkę cieplną przeprowadzono w 250, 300 i 350 °C przez 2, 3 i 4 godziny. Po obróbce cieplnej zaobserwowano wzrost związków międzymetalicznych (IMC), który był proporcjonalny do wzrostu temperatury. Analiza składu chemicznego przeprowadzona przez EPMA (Electron Probe Micro Analysis) potwierdziła obecność IMP takich jak θ (Al2Cu), η2 (AlCu), ξ2 (Al3Cu4), δ (Al2Cu3), γ1 (Al4Cu9). Mikrotwardość zmniejszyła się po obróbce cieplnej w bimetalu, ale znacznie wzrosła na granicy faz w wyniku tworzenia IMC

Zastosowanie metody EBSD na bimetalicznych polączeniach spawanych wybuchowo Al - austenitycznej stali CrNi

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.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

Effect of Rapid Quenching on the Solidification Microstructure, Tensile Properties and Fracture of Secondary Hypereutectic Al-18%Si-2%Cu Alloy

In this work, the effect of rapid quenching from the partially liquid and solid condition is studied on the as-cast microstructure, tensile properties and fracture features of a secondary hypereutectic Al-18%Si-2%Cu alloy. For comparison purposes, the same ingots of 50 mm in diameter and 300 mm in height were also fabricated using conventional chill casting. The microstructure of the samples was subjected to detailed characterisation using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses. The tensile properties and fracture were also evaluated. A significant grain refinement of the eutectic constituents (α (Al) + Si), as well as primary silicon and intermetallics accompanying coarse plate and Chinese script with a well-dispersed morphology transition for the intermetallics, was observed in the alloy subjected to the rapid quenching. The connection between primary and eutectic silicon was shown metallographically, confirming the fact that primary silicon served as a nuclei site for eutectic silicon. The microstructure refinement, together with a favourable morphology transition, resulted in greatly enhanced tensile properties and the more ductile fracture behaviour of the studied alloy