Solutions for Aluminum
Calculate the following based on your actual alloy chemistry:
Application Examples
Predicting Formation of ꞵ-Al9Fe2Si2 in A3003
The composition specification for A3003, a general purpose Al-Mn alloy, allows for Fe contents up to 0.7wt%. However, at higher iron concentrations, an intermetallic phase, ꞵ-Al9Fe2Si2, can precipitate, which has a detrimental effect on the mechanical properties. Thermo-Calc can be used to predict the stability of ꞵ-Al9Fe2Si2 as a function of alloy chemistry and temperature.
The figure shows that ꞵ-Al9Fe2Si2 is stable over a wide temperature range, and three times as much of this phase forms as the iron content increases from 0.2% to 0.7%. If this phase should be avoided for a certain application, then the iron content needs to be strictly controlled in order to suppress the transformation from α to ꞵ-Al9Fe2Si2.
Predicting Susceptibility to Hot Tearing using Scheil Simulations
The non-equilibrium freezing range of an alloy can be calculated using the Scheil Solidification Simulation Calculator included in Thermo-Calc and is related to the susceptibility of cast alloys to hot tearing. Typically, the narrower the range, the less susceptible the cast alloy is to hot tearing.
This figure shows the non-equilibrium solidification range of AA7075 compared to a common casting alloy, A356.1. The solidification range of AA7075 is quite large, indicating a higher susceptibility to hot cracking, which is also seen experimentally.
Predicting Susceptibility to Hot Tearing using the Property Model Calculator
A more comprehensive way to predict the likelihood of hot tearing, in addition to the previous example, is using the built-in Property Model for Crack Susceptibility Coefficient (CSC). This model is based on the Scheil Model, which is then utilized to calculate the crack susceptibility coefficient wherein the user can decide between three commonly used models in literature, namely Clyne and Davies [1], Kou [2], and Easton [3] models. This model is beneficial for doing batch calculations and accounting for chemical variations.
The plot shows the CSC Model calculated for an Al-Si alloy using the Clyne and Davies model. The plot compares the predicted cracking susceptibility/composition curve for the Al-Si system with the experimental hot tearing tendencies.
This calculation is available as example PM_G_07 in the example files shipped with the software. A video is available demonstrating this model, which you can watch at the Property Model Calculator Video page.
[1] T. W. Clyne and G. J. Davies, “The Influence of Composition on Solidification Cracking Susceptibility in Binary Alloy Systems,” Br. Foundrym., vol. 74, no. 65–73, 1981.
[2] S. Kou, “A criterion for cracking during solidification,” Acta Materialia, 88, 366–374, 2015. https://doi.org/10.1016/j.actamat.2015.01.034
[3] X. Yan and J. C. Lin, “Prediction of hot tearing tendency for multicomponent aluminum alloys,” Metall. Mater. Trans. B Process Metall. Mater. Process. Sci., 2006, https://doi.org/10.1007/BF02735013
Predicting Thermophysical Properties of Alloy 356.1
Latent heat release during solidification is a critical value needed for many casting, welding, and additive manufacturing finite element simulations. Typically, handbooks give only a single value for latent heat, whereas in reality the latent heat evolution occurs over the entire solidification temperature range. The evolution of latent heat as a function of chemistry and temperature can be predicted using the Scheil Solidification Simulation Calculator in Thermo-Calc. This temperature dependent data can be used by finite element models for more accurate simulations.
The figure shows the latent heat calculated as a function of temperature for Alloy 356.1.
Learn more about Applications to Al-based Alloys
An integrated computational materials engineering-anchored closed-loop method for design of aluminum alloys for additive manufacturing
Improvement of the high-pressure die casting alloy Al-5.7Mg-2.6Si-0.7Mn with Zn addition
