Papers by Keyword: AlMgSi

Abstract: The properties and surface appearance of aluminium extrusion are critically dependent on the microstructure and texture of the extruded profiles, and the requirements with respect to these aspects may vary with applications. Moreover it is often a challenge to produce extrusions with a consistent and homogenous grain structure and texture along as well as through the cross section of the profiles. It is thus vital to understand and be able to predict (model) how different microstructures and textures are formed and how they evolve during and after extrusion. In the present work a model framework has been implemented which includes a FEM model to account for the strain, strain rate and temperature along a set of particle paths during extrusion. From these the deformation texture and grain structure are calculated with an appropriate deformation texture model and a sub-structure evolution model, respectively. The sub-structure model have in the present work been coupled to a crystal plasticity model to provide an orientation dependent subgrain size and dislocation density during deformation which provides the driving force for the post-extrusion recovery and possible recrystallization behaviour. The post-extrusion microstructure and texture evolution is calculated with a recovery and recrystallization model, which is accompanied by a recrystallization texture model. The framework and its constituent models and their interplay are presented, and some preliminary results when applying this modelling framework to Al-Mg-Si extrusions are presented and discussed in view of corresponding experimental results.

Abstract: In the past months due to decreasing fuel prices the brisance of light weight design got lost, however climate change is still continuing and there is an increasing demand for aluminum parts for mobile applications. There is a strong rivalry between well-known materials such as aluminum, steel and plastic, however technical progress features new materials such as carbon fiber laminates (CFK). New competitors in North America and China are increasing the cost pressure, which requires further process optimizations. In this work different fabrication methods for impact extruded parts are analyzed and economical and technological aspects are compared. A comparison between traditional and state-of-the-art production routes is done. Based on an input-output analysis the alternatives are compared by economic and ecologic aspects, allowing a substantiated examination. Through the comprehensive analysis, options for technological optimizations are revealed to attenuate disadvantages of alternatives with economic advantages, ensuring technological leadership.

Abstract: The subject of the work focuses on hardened-precipitation type alloys Al-Mg-Si which constitute the primary component material used to build homogeneous electric wires, type AAAC (All Aluminium Alloy Conductor). The material in consideration is a well-known and well-studied alloy, particularly in terms of the possibilities for using it in thermal treatment processes. However, the subject literature does not present a comprehensive recognition of the effect of heat treatment parameters on the set of mechanical and electrical properties in wires grade 6101. In particular, the study presents the results of experiments that show the possibility of controlling the AlMgSi wire properties by means of selecting the heat treatment parameters for simultaneously obtaining a high tensile strength and high electrical conductivity. Hence, the research described in this paper focuses mostly on determining the impact of the Mg and Si content on the electrical and mechanical properties of wires of Al-Mg-Si wire alloys.

Abstract: The authors of this paper present the research results of low temperature creep of AlMgSi (6101) wires and AAAC - All Aluminium Alloy Conductor. The conductor is made from AlMgSi wires (diameter 2.99 mm). Based on theoretical analysis it was proved that creep of an overhead conductors depends on the relation between stress and temperature of conductor and the span geometry. Thus the objective of the paper is to determine the wire and conductor creep under the conditions of stress drop. On the basis of the research it has been observed that the creep of both the AAAC conductor and the AlMgSi wires temporarily stopped.

Abstract: Precipitation hardening AlMgSi alloys are widely used not only as constructional material, but also a very attractive material for the manufacturing of conductors for overhead power lines. These alloys, with a mass density typical of aluminum and with relatively low resistivity, reach twice the level of mechanical properties, compared to aluminum. Semi-finished product in the manufacturing of overhead conductors is wire rod produced by the technology of the continuous casting and rolling (CCR), for example Continuus-Properzi. The entire complex of wire rod required properties (electrical, tensile, rheological, fatigue) are obtained through proper selection of the quantities of alloying elements (Si, Mg) and structure modifier (Fe, Ti) as well as the right combination of type and sequence of thermo-mechanical treatments and technological process parameters. The article discusses the physical background of opportunities to controlling the wire rod properties, taking into consideration all elements of technology for continuous casting and rolling and also thermo-mechanical treatments. In particular, article contains the presentation and analysis of investigations results identifying the structure, electrical properties and hardness of materials from particular stages of the process, refer to physical phenomena affecting the properties of the material during CCR process including the final product intended for the manufacture of wires.

Abstract: The present work focuses on a physical description of phenomena occurring during the heat treatment of a cold deformed aluminium sheet. The major practical interest lies in the prediction of microstructural changes and their impact on the yield strength. The material softening part was described due to thermally activated glide of dislocations. The precipitation kinetics are calculated by using the computational thermodynamics program MatCalc (MATerials CALCulator). The model was validated by comparison with experimental data from tensile tests of cold deformed and heat treated sheets. Finally, it was shown that the model can be used to predict the yield strength during heat treatment of Al-Mg-Si alloys.

Abstract: The paper focuses on 6xxx series AlMgSi conductor alloys. Such alloys are used for manufacturing of conductors for power transmission. Since the most current standards define as many as seven types of wires with various mechanical and electrical specifications, the existing philosophy of AlMgSi wires manufacturing technology for electrical applications has to be revised. Strength specifications of precipitation hardened AlMgSi alloys may be enhanced by strain and by precipitation hardening. Therefore from the scientific point of view identification seems to be relevant of the impact of the sequence of these mechanisms on development of final wire properties. In particular, this paper tries to answer the following question: Does the sequence of hardening mechanisms affect the development of mechanical properties of AlMgSi alloy wires The paper presents results of a study of the impact of artificial ageing parameters of 6201 grade AlMgSi alloy wires on their final properties. The study results are presented and discussed in two parts. The first part addresses the impact of artificial aging temperature and duration on the strength properties of AlMgSi (grade 6201) alloy wire rod. The second part is focused on hardening development in the process of drawing of a AlMgSi wire made of the same alloy grade, subjected to different thermal treatments, the parameters of which have been selected based on analysis of the results of the first, wire-rod related, part of the study.