ABSTRACT
The elaboration concerns Mg-Al-Zn-Mn casting magnesium alloys. Magnesium alloys are commonly used in the automotive, electronic and aerospace industries, in electrical engineering and for building elements, as well as in the arms industry, optical sector, sports sector and others. In the presented general characteristics of magnesium alloys and alloy additives, attention was also drawn to the general methodological aspects of the presented own research into Mg-Al-Zn-Mn alloys. The effect of the cooling rate and mass concentration of Al on the kinetics of alloys crystallisation was described. Another aspect outlined is represented by the effect of heat treatment conditions and different cooling mediums on the structure of the investigated alloys. The results of own investigations were presented, concerning surface layers deposition by Physical (PVD) and Chemical (CVD) Vapour Deposition techniques. The results of investigations concerning the surface treatment of Mg-Al-Zn-Mn alloys were also presented. Another section of the paper analyses the effect of surface treatment process carried out through rapid heating, and then rapid crystallisation, and imbed of hard ceramic particles into the laser remelted surface zone using carbides of titanium, tungsten, vanadium, niobium, tantalum and aluminium oxide with the use of high-performance diode lasers (HPDL) on the structure and properties of the investigated materials. An ultramodern and contactless method of energy transfer using laser radiation is one of the most dynamically developing technological areas and for this reason, the presented original results of research in this field are especially noteworthy. It was revealed through interdisciplinary investigations with technology foresight methods – including materials science experiments, notably light and scanning microscopy, X-ray phase qualitative analysis and surface distribution analysis of chemical elements and investigations into mechanical properties (hardness, microhardness) and roughness, as well as expert studies, allowing to identify long-run development prospects of casting magnesium alloys subjected to laser treatment – that this specific group belongs to a group of critical technologies, and more than 80% of experts claim that the occurrence of a positive development scenario in the next 20 years is dependent on this very technology. A section comprising the outcomes of materials science and heuristic research in relation to Mg-Al-Zn-Mn alloys, prepared based on the author's original research e-foresight methodology, represents a very valuable part of this elaboration, and is decisive, among others, for its scientific originality and for its contribution towards the development of materials engineering and materials science. The elaboration also contains a computer analysis, enabling to determine and/or predict the phenomena taking place in the examined Mg-Al-Zn-Mn alloys, using neural networks, in scope of optimisation for heat treatment conditions, modelling of the structure and mechanical properties based on the temperature of phase transformations and cooling rate, as well as the modelling of the mechanical properties of magnesium alloy surfaces remelted and modified on the surface by laser imbed of hard ceramic particles into remelted surface zone. It should be noted that still an avant-garde methodology of computer materials science represents an attractive and modern tool for designing engineering materials. This also constitutes the scientific originality and the authors’ contribution towards the development of research methodologies of materials engineering and materials science.
