Major alloying elements, Si, Cu, and Mg, are primarily responsible for defining the microstructure of the aluminum alloy. These alloys are characterized by their low density, light weight, relative low melting temperatures, negligible gas solubility (with the exception of hydrogen), excellent castability, good corrosion resistance, electrical, and thermal conductivity and good machinability. The cast aluminum-silicon alloys are widely used in many automotive components. of Si will be used as the eutectic concentration of silicon as well as 577☌ as the temperature at which eutectic reaction occurs. In the available literature the following values for eutectic concentration of silicon were found: 11.9 wt.%, 12.2 wt.%, 12.3 wt.% and 12.6 wt.% In this work the value of 12.3 wt.%. The concentration of silicon, which corresponds to the eutectic reaction, is still not accurately defined or accepted among researchers, despite the fact that this diagram has been investigated often. The maximum solubility of aluminum in silicon at the eutectic temperature is still questionable, and according to some literature data, it is approximately 0.015 wt.%. The solubility of silicon in the aluminum melt reaches a maximum of 1.6 wt.% at the 577☌ eutectic temperature. The melting temperature of pure aluminum is 660☌. As Figure 1 shows, it is a binary eutectic type phase diagram with limited aluminum and silicon solubility.
Az91 fluidity magmasoft series#
The Al-Si phase diagram is the base component system for the Al-Si series of alloys. These are based on experimental data obtained under equilibrium solidification conditions. For the binary aluminum and magnesium alloys, liquidus temperature/composition relations can easily be derived from highly accurate binary diagrams. Moreover, some of these equations are not sufficiently verified by experimental data. Unfortunately, only few equations are reported in the literature that relate the compositions of many commercially important nonferrous and ferrous alloys to their liquidus temperatures. In order to predict the various physical parameters of a solidifying aluminum and magnesium alloys (e.g., fraction solid), the liquidus temperatures of these alloys must be known with the highest possible degree of accuracy. The calculated liquidus temperatures for wide ranges of alloy chemical compositions show a good correlation with corresponding measured liquidus temperatures. The sum of the equivalent concentrations for other elements, when added to the influence of the actual reference element is used to calculate the liquidus temperature of the alloy. Silicon as a reference element has been chosen for aluminum alloys and aluminum for magnesium alloys. The analytical expressions presented in this paper are based on the “method of equivalency.” According to this concept, the influence of any alloying element on the liquidus temperature of an aluminum and/or magnesium alloy can be translated into the equivalent influence of a reference element. An accurate knowledge of liquidus temperature permits a researcher to predict a variety of physical parameters pertaining to a given alloy. The purpose of this paper is to develop a mathematical equation, which will be able to accurately predict the liquidus temperature of various aluminum and magnesium cast alloys on the basis of their known chemical compositions.
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