In a breakthrough that could significantly impact the maritime industry, researchers have developed a novel two-step sintering strategy to produce highly transparent aluminum oxynitride (AlON) ceramics. The study, led by Haoran Guo from the Department of Materials Science and Engineering at Dalian Maritime University in China, was recently published in the Journal of Advanced Ceramics, also known as the Journal of Advanced Ceramics.
So, what’s the big deal? Well, imagine a material that’s as clear as glass but as tough as steel. That’s AlON for you. It’s already used in things like bulletproof windows and missile domes, but making it transparent has been a challenge. The traditional method, conventional sintering (CS), takes a long time and doesn’t always produce the best results. But Guo and his team have found a way to speed things up and improve quality using a combination of ultra-fast high-temperature sintering (UHS) followed by CS.
Here’s how it works: they heat the AlON to 1850°C for just two minutes in the UHS step, then follow it up with a 120-minute sintering at 1880°C. The result? A material with a transmittance of over 80% across a wide range of wavelengths, from 350 to 4900 nm. That’s a significant improvement over the traditional method.
Guo explains, “The high relative density of the UHSed sample, along with the predominance of small grains and nonequilibrium grain boundaries induced by UHS, contributes to the rapid densification of AlON during subsequent CS.” In simpler terms, the quick initial heating creates a dense, fine-grained material that’s easier to fully densify in the second step, leading to a more transparent and harder final product.
So, what does this mean for the maritime industry? Transparent ceramics like AlON have a lot of potential applications at sea. They could be used in windows for submarines or other underwater vehicles, providing a clear view while withstanding the extreme pressures of the deep ocean. They could also be used in periscopes, portholes, or even in advanced sensors and optical systems.
Moreover, the improved hardness and transparency could enhance the durability and performance of maritime equipment. As Guo points out, “The excellent transparency and high hardness (HV = 19.57±0.23 GPa) of the final product” make it a promising material for harsh environments.
This new sintering strategy could also make AlON more cost-effective to produce, opening up even more opportunities for its use in the maritime sector. As the technology develops, we could see it becoming a standard material in many types of maritime equipment.
In the meantime, researchers will continue to explore the potential of this novel sintering strategy. As Guo and his colleagues conclude, “UHS+CS is an effective and efficient strategy for fabricating highly transparent AlON ceramics, with UHS being a crucial step.” With further refinement, this could be a game-changer for the maritime industry.