The paper presents the results of theoretical analysis and experimental research on the material’s influence and tool geometry on the welding speed and mechanical strength of Al 2024 thin sheet metal joints. To make the joints, tungsten carbide and ceramics tools with a smooth and modified surface of the shoulder were used. The choice of the geometrical parameters of the tool was adjusted to the thickness of the joined sheet. During welding, the values of axial and radial force were recorded to determine the stability of the process. The quality of the joint was examined and evaluated on the basis of visual analysis of the surface and cross-sections of the joint area and the parent material, and subjected to mechanical strength tests. The test results indicate that both the geometry of the tool shoulder and the tool material have a decisive influence on the quality of the joint and the welding speed, making it possible to shorten the duration of the entire process.
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Purpose: In the present study, the effects of B4C reinforcement volume fraction (% 5-15-20) on the abrasive wear properties of AA2024 matrix composites produced with hot pressing methods were investigated. Design/methodology/approach: As-received samples were also used for comparison. AA 2024 powder was mixed with B4C-SiC-Al2O3 particles by a three dimensional mechanic mixer for 30 minutes. Mixed powder was pressed under 60 MPa at room temperature in the steel mold by unidirectional. Steel mold kept in the furnace at 550ºC after the pre-pressing for 30 minutes. Samples were pressed in heated mold under 100 Pa. The wear tests were carried out using a pin-on-disk wear tester by sliding at sliding speeds of 1.2 m/s against silicon carbide paper. Normal loads of 10, 20 and 30 N at constant sliding speed at room temperature. Findings: The experimental result showed that B4C volume fraction significantly influence the wear behavior of AA2024 matrix composites produced with hot pressing methods. Originality/value: It was also found that the wear resistance of AA2024 matrix composites produced with hot pressing methods increases with increasing B4C volume fraction. The highest weight loss was obtained in the unreinforced matrix material.
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W artykule opisano wpływ trawienia powierzchni blach ze stopu AA2024 na właściwości korozyjne. Porównane zostały powierzchnie polerowane i czyszczone dwoma różnymi procedurami (1) odtłuszczaniem w acetonie oraz etanolu oraz (2) trawieniem w roztworze alkalicznym oraz kwaśnym. Różnice w odporności korozyjnej wyjaśniono w oparciu o obserwowacje struktury przy użyciu skaningowego mikroskopu elektronowego (SEM). Skład chemiczny elementów mikrostruktury był badany przy użyciu spektrometru dyspersji energii (EDS). Określono wpływ trawienia na skład chemiczny wydzieleń oraz morfologię powierzchni blach.
EN
In the article the influence of surface pretreatment before the anodization process on the corrosion properties of AA2024 is reported. A comparison of two different procedures of surface preparation has been made: (1) cleaned with acetone and ethanol and (2) etched in alkaline solution followed by etching in acidic. Differences in the corrosion resistance were explained after observations of structure and morphology of the layers via scanning electron microscopy (SEM). The chemical composition of the microstructure elements was investigated with the use of energy dispersion spectrometer (EDS). The surface was characterized using scanning electron microscope (SEM) equipped with and The effect of the etching on the chemical composition of precipitates and morphology of the sample surface was determined.
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