Researchers in the US have reinvented a 26,000-year-old manufacturing process into an innovative approach to fabricating ceramic materials that has promising applications for solid-state batteries, fuel cells, 3D printing technologies, and beyond.
Ceramics are widely used in batteries, electronics and extreme environments – but conventional ceramic sintering (part of the firing process used in the manufacture of ceramic objects) often requires hours of processing time. To overcome this challenge, a team led by researchers from the University of Maryland (UMD) has now invented an ultrafast high-temperature sintering method that both meets the needs of modern ceramics and fosters the discovery of new material innovations.
The researchers, led by Liangbing Hu, a professor in the A. James Clark School of Engineering and director of the Center for Materials Innovation at UMD, report their advance in a paper in Science. Chengwei Wang, an assistant research scientist in Hu's group, served as first author on the paper; other team members came from the University of California, San Diego and the University of California, Los Angeles (UCLA).
Conventional sintering techniques require a long processing time – it takes hours for a furnace to heat up, then several hours more to 'bake' the ceramic material – which is particularly problematic when developing electrolytes for solid-state batteries. Alternative sintering technologies (such as microwave-assisted sintering, spark plasma sintering and flash sintering) are limited for a variety of reasons, often because they are material-specific and/or expensive.
The UMD team's new method of ultrafast high-temperature sintering offers high heating and high cooling rates, an even temperature distribution, and sintering temperatures of up to 3000°C. Combined, these processes require less than 10 seconds of total processing time – more than 1000 times faster than the traditional furnace approach of sintering.
"With this invention, we 'sandwiched' a pressed green pellet of ceramic precursor powders between two strips of carbon that quickly heated the pellet through radiation and conduction, creating a consistent high-temperature environment that forced the ceramic powder to solidify quickly," explained Hu. "The temperature is high enough to sinter basically any ceramic material. This patented process can be extended to other membranes beyond ceramics."
"Ultrafast high-temperature sintering represents a breakthrough in ultrafast sintering technologies, not only because of its general applicability to a broad range of functional materials, but also due to a great potential of creating non-equilibrium bulk materials via retaining or generating extra defects," said team member Jian Luo, a professor at the University of California, San Diego.
The rapid sintering technology is being commercialized through HighT-Tech LLC, a UMD spinoff company with a focus on a range of high temperature technologies.
"This new method solves the key bottleneck problem in computation and AI-guided materials discovery," said team member Yifei Mo, an associate professor at UMD. "We've enabled a new paradigm for materials discovery with an unprecedented accelerated pace."
"We are delighted to see the pyrolysis time reduced from tens of hours to a few seconds, preserving the fine 3D-printed structures after fast sintering," added team member Xiaoyu Zheng, an assistant professor at UCLA.
This story is adapted from material from the University of Maryland, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.
