In the relentless pursuit of lighter, stronger materials, researchers at the University of Science and Technology MISIS in Moscow have made a significant breakthrough that could reshape the future of magnesium alloys, particularly in the energy sector. Led by Andrey V. Pozdniakov, a team of scientists has developed a model to predict the hot brittleness of magnesium alloys, a critical factor in their casting and manufacturing processes.
Magnesium alloys, known for their exceptional strength-to-weight ratio, are increasingly sought after in industries where weight reduction is paramount, such as automotive and aerospace. However, their tendency to exhibit hot brittleness during casting has long been a stumbling block. This phenomenon, where the alloy becomes brittle at high temperatures, can lead to defects and failures in the final product.
The team’s research, published in Frontier Materials & Technologies, focuses on the effective solidification range (ESR) of magnesium alloys, particularly those based on Mg–Al and Mg–Zn systems. The ESR is the temperature range over which an alloy solidifies, and it plays a crucial role in determining the alloy’s hot brittleness.
Pozdniakov and his team used the Thermo-Calc program with the TTMG3 database to calculate the ESR of various magnesium alloys. They found that the ESR, when calculated at specific solid phase percentages, correlated well with the hot brittleness index (HBI) of the alloys. “We observed a good correlation between the calculated values of ESR and HBI in both binary and multicomponent magnesium alloys,” Pozdniakov explained. This correlation is particularly strong in Mg–Al system alloys, where the ESR at 90% solid phases showed the best match with experimental HBI values.
The implications of this research are far-reaching, especially for the energy sector. As the push for lighter, more fuel-efficient vehicles and aircraft continues, the demand for high-performance magnesium alloys is set to soar. However, the tendency of these alloys to exhibit hot brittleness has hindered their widespread adoption. The model developed by Pozdniakov’s team could change this, enabling manufacturers to predict and mitigate hot brittleness more effectively.
The model divides magnesium alloys into two groups based on their ESR and HBI relationship: the Mg–Al–Zn system alloys and the Mg–Zn–Zr and Mg–Nd–Zr alloys. Within these groups, the dependence of HBI on ESR is nearly linear, allowing for a single equation to describe the relationship. This simplicity could make the model a valuable tool for alloy developers and manufacturers.
The research also highlights the potential for thermodynamic calculations to guide the development of new, high-tech magnesium alloys. By understanding and predicting the ESR and HBI of different alloy compositions, researchers can design alloys that are less prone to hot brittleness, leading to improved casting processes and higher-quality products.
As the energy sector continues to evolve, the demand for innovative, high-performance materials will only grow. The work of Pozdniakov and his team at the University of Science and Technology MISIS represents a significant step forward in meeting this demand. Their model, published in Frontier Materials & Technologies, could pave the way for a new generation of magnesium alloys, driving progress in industries ranging from automotive to aerospace. The future of magnesium alloys is looking brighter, and it’s all thanks to a deeper understanding of their solidification behavior.
