you ever melted a tub of butter by leaving it too close to your electric frying
pan? Have you ever left a plastic
cutting board on the stove before turning on the burner? If you answered “Yes, I have!” to any of
those questions, then worry no more!
Thanks to science, heat-proof spatulas and cutting boards are no longer
a thing of the future. Unfortunately, if
you want the most heat-resistant spatula possible, you’re going to have to get
over the ridiculously high price tag.
the 1960’s, scientists discovered and began experimenting with Tantalum Hafnium
Carbide compounds. They found a few variations
with melting points just below 4000?. Despite their potential, not much was
done with Tantalum Hafnium Carbide. Ta-Hf-C
is too expensive to produce on a large scale, and there wasn’t much need for an
intensely heat resistant material like Ta-Hf-C in the 60s. According to the
NASA Institute for Advanced Concepts, Ta-Hf-C costs around $9540/kg. (Dr. Ralph L.
McNutt, Jr., 2003)
scientific interest in Ultra-High-Temperature-Ceramics like Ta-Hf-C has been
rekindled because they are the only materials able to withstand the high
temperatures present in ultrasonic travel. In 2015, a team of researchers at
Brown University broke the record for highest melting point using advanced
computer models. (Gebelhoff, 2015) They discovered a
theoretical compound made from Hafnium, Carbon, and Nitrogen with a melting
point of 4190?.
advantage of starting with the computational approach is we can try lots of
different combinations very inexpensively and find ones that might be worth
experimenting with in the lab,” says Axel van de Walle, associate
professor of engineering at Brown University. “Otherwise we’d just be
shooting in the dark. Now we know we have something that’s worth a try.” (New material
has higher melting point than any known substance, 2015)
The next step is to find a way to create N-Hf-C
in a laboratory. Even after two years,
there is little evidence that researchers have had any success in finding a
method for N-Hf-C synthesis. Whether or not N-Hf-C can be easily created in a
lab, it doesn’t look like it’s going to be used commercially.
that doesn’t mean there aren’t other compounds that can withstand temperatures
over 4000?. In 2014, PhD student Mr Omar
Cedillos carried out experiments at the Institute for Transuranium Elements
(ITU) in Karlsruhe, Germany. He used a high powered laser technique, which they
normally use to understand how ceramics perform is nuclear reactors. The technique uses lasers to create the
intense, focused heat required to melt the UHTC. Another laser is used to analyze
how the material melts as it is being heated. A device called a pyrometer
measures the material’s melting point. (Wang, 2014) This method
determined the melting point for Hafnium carbide to be 4050?.
Ultra-High-Temperature-Ceramics (UHTFs) have a few potential uses. The first is for ultrasonic travel, where the
ceramic will protect the nose and wings of the aircraft. Next is for nuclear reactors, where they could
be used to help contain the heat from the reactor. They could also be used as plating for gas turbines. Sadly, UHTFs probably won’t make good cutting
boards or spatulas.
is still a long way to go before UHTFs can be used for aircraft. Researchers still need to find a way to
prevent the ceramics from reacting with atmospheric oxygen and degrading. They also need cheap ways to obtain hafnium
or Tantalum and cheaper methods to mass-produce the ceramics. Until then, we’re stuck with what we have.
Dr. Ralph L. McNutt, Jr. (2003). A Realistic
Interstellar Explorer, Phase 2 Final Report. NASA Institution for Advanced
Gebelhoff, R. (2015). Behold! A new record for the
world’s highest melting point. Washington Post.
(2015). New material has higher melting point than
any known substance. ASM international.
Wang, B. (2014, September 14). Rediscovered
ceramic Hafnium Carbide can withstand temperatures three times hotter than
lava at 4050 celsius and could help enable hypersonic planes. Retrieved
from Next Big Future: