In the quest to bolster the performance of nickel-based superalloys, a team of researchers led by Chang Shu from the University of Birmingham’s Department of Mechanical Engineering has made a significant stride. Their work, published in the journal *Materials & Design* (which translates to *Materials & Design* in English), focuses on enhancing the properties of IN738LC superalloys using a novel approach that could have profound implications for the aerospace and energy sectors.
Nickel-based superalloys are the workhorses of high-temperature applications, thanks to their exceptional mechanical properties. However, their potential can be further unlocked through reinforcement strategies. Shu and his team have proposed a multiscale titanium carbide (TiC) reinforcement strategy, leveraging Laser Powder Bed Fusion (L-PBF) technology to create composites with superior strength and hardness.
The team prepared a composite feedstock by mixing coarse and fine TiC particles with IN738LC powder. During the L-PBF process, in situ reactions formed nano-TiC phases, leading to significant grain refinement. “This multiscale approach allows us to achieve a more homogeneous microstructure and better mechanical performance compared to single-scale nano-TiC approaches,” Shu explained.
The researchers conducted a full-factorial experimental design to optimize the L-PBF parameters. They found that a laser power of 150 W, a scanning speed of 500 mm/s, and a hatch spacing of 0.09 mm yielded the best results in terms of porosity, microhardness, and tensile properties. The multiscale TiC reinforcement led to improved strength and hardness, with only a slight reduction in ductility, which remained superior to conventional mixing routes.
Microstructural analysis revealed enhanced grain refinement, reduced residual stress, and suppressed oxides and cracks. These improvements are crucial for applications in the energy sector, where materials are often subjected to extreme conditions. “The enhanced properties of these composites make them ideal for high-temperature applications, such as turbine blades and other critical components in the aerospace and energy industries,” Shu noted.
The implications of this research are far-reaching. By demonstrating the feasibility and advantages of multiscale TiC reinforcement, Shu and his team have opened up new possibilities for advancing the additive manufacturing of high-performance nickel-based superalloys. This could lead to more efficient and reliable components, ultimately benefiting the energy sector by improving the performance and longevity of critical infrastructure.
As the energy sector continues to evolve, the demand for materials that can withstand extreme conditions will only grow. The work of Shu and his team represents a significant step forward in meeting this demand, paving the way for more innovative and sustainable solutions in the future.