HPDL Remelting of Anodised Al-Si-Cu Cast Alloys Surfaces

The results of the investigations of the laser remelting of the AlSi9Cu4 cast aluminium alloy with the anodised and non-anodised surfacelayer and hardness changes have been presented in this paper. The surface layer of the tested aluminium samples was remelted with thelaser of a continuous work. The power density was from 8,17•103 W/cm2 to 1,63•104 W/cm2. The metallographic tests were conducted inform of light microscope investigations of the received surface layer. The main goal of the investigation was to find the relation betweenthe laser beam power and its power density falling on a material, evaluating the shape and geometry of the remelted layers and theirhardness. As the substrate material two types of surfaces of the casted AlSi9Cu4 alloy were applied – the non–treated as cast surface aswell the anodized surface. As a device for this type of surface laser treatment the High Power Diode Laser was applied with a maximumpower of 2.2 kW and the dimensions of the laser beam focus of 1.8 x 6.8 mm. By mind of such treatment it is also possible to increasehardness as well eliminate porosity and develop metallurgical bonding at the coating-substrate interface. Suitable operating conditions forHPDL laser treatment were finally determined, ranging from 1.0 to 2.0 kW. Under such conditions, taking into account the absorptionvalue, the effects of laser remelting on the surface shape and roughness were studied. The results show that surface roughness is reducedwith increasing laser power by the remelting process only for the non-anodised samples, and high porosity can be found in the with highpower remelted areas. The laser influence increases with the heat input of the laser processing as well with the anodisation of the surface,because of the absorption enhancement ensured through the obtained alumina layer

Phase identification of nanometric precipitates in AlSi9Cu alloy after remelting by laser beam

The aim of presented paper is an investigation of the structure changes in AlSi9Cu alloy after remelting by a laser beam. Scanning transmission electron microscopy was applied for structure characterization and precipitates phase identification. In the raw material, precipitates were larger and during remelting such precipitates were dissolved and very fast crystallization came next. Observed precipitates are generally uniform: in size, shape, and chemical composition. Generally, after remelting precipitates are not uniformly distributed in the whole sample but areas with dense, nanometric precipitates are common. Numerous volumes with elongated Ti precipitates, identified as Ti(Al_{1-x}Si_{x})₃, were found. Observed precipitate can strongly affect material properties (even in a case of law Ti concentration) because it may act as a crystal nucleus for other phases

Phase identification of nanometric precipitates in Al-Si-Cu aluminum alloy by HR-STEM investigations

Aluminium recycling is cost-effective and beneficial for the environment. It is expected that this trend will continue in the future, and even will steadily increase. The consequence of the use of recycled materials is variable and difficult to predict chemical composition. This causes a significant reduction in the production process, since the properties of produced alloy are determined by the inicrostructure and the presence of precipitates of other phases. For this reason, the type and order of formation of precipitates were systematically investigated in recent decades. These studies involved, however, only the main systems (Al-Cu. Al-Mg-Si, Al-Cu-Mg, Al-Mg-Si-Cu), while more complex systems were not analysed. Even trace amounts of additional elements can significantly affect the alloy inicrostructure and composition of precipitates formed. This fact is particularly important in the case of new technologies such as laser surface treatment. As a result of extremely high temperature and temperature changes after the laser remelting large amount of precipitates are observed. Precipitates are nanometric in size and have different morphology and chemical composition. A full understanding of the processes that occur during the laser remelting requires their precise but also time effectively phase identification, which due to the diversity and nanometric size, is a major research challenge. This work presents the methodology of identification of nanometer phase precipitates in the alloy AlSi9Cu, based on the simultaneous TEM imaging and chemical composition analysis using the dispersion spectroscopy using the characteristic X-ray. Verification is performed by comparing the simulation unit cell of the identified phase with the experimental high-resolution image

Prognozowany rozwój wybranych grup materiałów inżynierskich stosowanych w przemyśle motoryzacyjnym

Celem niniejszego artykułu jest prezentacja wyników ilościowej analizy porównawczej wybranych materiałów i technologii wytwarzania, wskazanie ich perspektyw rozwojowych oraz prezentacja możliwości aplikacyjnych w przemyśle motoryzacyjnym. Zapotrzebowanie na elementy i części wykonane z odlewniczych stopów aluminium zgłaszane przez przemysł motoryzacyjny sprawia, że perspektywy rozwojowe technologii efektywnego ich wytwarzania, zapewniających oczekiwane własności produktu, do których należy powierzchniowa obróbka laserowa, oraz metody fizycznego i chemicznego osadzania powłok z fazy gazowej zostały ocenione na poziomie bardzo wysokim.The purpose of the article is to present the results of comparative quantitative analysis of selected materials and manufacturing technologies, to indicate their development outlooks and to present its application opportunities in the automotive industry. Concerning of the demand from the automotive sector for components and parts made of cast aluminum alloys, the development expectations of their effective manufacturing technology meeting the expected product properties, including surface laser treatment as well as physical and chemical vapour deposition, were evaluated to be very high

Nano-Scale Structure Investigation of Vapour Deposited AlCrSiN Coating Using Transmission Electron Microscope Techniques

The investigations concerned the structural analysis of the AlCrSiN coating deposited by arc Physical Vapour Deposition method on the X40CrMoV5-1 hot work tool steel substrate. The deposition process was carried out on a device equipped with a technique of lateral, rotating cathodes. The nano/microstructure, phase identification and chemical state of the coating were analysed by high-resolution transmission electron microscopy. It was found that the investigated coatings have nanostructured nature consisting of fine crystallites. The fractographic tests were made using the scanning electron microscope and allow to state, that the coating was deposited uniformly and tightly adhere to the substrate material. In the work is presented the nature of a transition zone between the produced AlCrSiN coating and substrate material

Nano-Scale Structure Investigation of Vapour Deposited AlCrSiN Coating Using Transmission Electron Microscope Techniques

The investigations concerned the structural analysis of the AlCrSiN coating deposited by arc Physical Vapour Deposition method on the X40CrMoV5-1 hot work tool steel substrate. The deposition process was carried out on a device equipped with a technique of lateral, rotating cathodes. The nano/microstructure, phase identification and chemical state of the coating were analysed by high-resolution transmission electron microscopy. It was found that the investigated coatings have nanostructured nature consisting of fine crystallites. The fractographic tests were made using the scanning electron microscope and allow to state, that the coating was deposited uniformly and tightly adhere to the substrate material. In the work is presented the nature of a transition zone between the produced AlCrSiN coating and substrate material

Anodization of cast aluminium alloys produced by different casting methods

Abstract In this paper the usability of two casting methods, of sand and high pressure cast for the anodization of AlSi12 and AlSi9Cu3 aluminium cast alloys was investigated. With defined anodization parameters like electrolyte composition and temperature, current type and value a anodic alumina surface layer was produced. The quality, size and properties of the anodic layer was investigated after the anodization of the chosen aluminium cast alloys. The Alumina layer was observed used light microscope, also the mechanical properties were measured as well the abrasive wear test was made with using ABR-8251 equipment. The researches included analyze of the influence of chemical composition, geometry and roughness of anodic layer obtained on aluminum casts. Conducted investigations shows the areas of later researches, especially in the direction of the possible, next optimization anodization process of aluminum casting alloys, for example in the range of raising resistance on corrosion to achieve a suitable anodic surface layer on elements for increasing applications in the aggressive environment for example as materials on working building constructions, elements in electronics and construction parts in air and automotive industry