Amazing stuff!
"A new nickel-based super-metal alloy that maintains strength and flexibility over an 800oC temperature range has been developed in [South] Korea.
A team at researchers ... called its high entropy alloy (HEA) the first of the ‘hyperadaptors’.
“Our HEA breaks through the limitations of existing alloys and establishes a new class of temperature-insensitive materials,” s... “The Hyperadaptor concept represents a breakthrough in developing next-generation materials with consistent mechanical behaviour even under extreme conditions.” ...
HEAs are a little more complex, typically containing five or more elements in about equal proportions. Like metal smoothies, no ‘flavour’ dominates. Originating in the early 2000’s, scientists are looking for stronger, tougher or more corrosion-resistant alloys. ...
high entropy helps to stabilise the solid phase for these alloys. So if mixed thoroughly in the molten phase, the resulting hardened alloy tends to be mechanically tougher and more thermally stable than those with fewer elements. ...
The most famous HEA is probably the ‘Cantor alloy’ named after Professor Brian Cantor of the University of Oxford. An alloy of cobalt, chromium, iron, manganese and nickel (Co, Cr, Fe, Mn and Ni), this material is still flexible under “cryogenic temperatures,” typically liquid nitrogen at -196oC. ...
The POSTECH HEA ... Made from 35% nickel, with the combination of iron, cobalt and chromium at 53% , plus aluminium (7%) and titanium (5%) their HEA was a ‘face-centred cube (FCC) ... That’s one atom at each corner of the cube (8 corners in total), plus one atom at the centre of each face of the cube (6 faces). ..."
"... The newly developed HEA demonstrates nearly constant mechanical performance across a wide temperature range—from cryogenic conditions at -196°C (77 K) to high heat at 600°C (873 K). This remarkable stability is attributed to the presence of nanoscale L1₂ precipitates , which are uniformly distributed within the alloy. These fine particles act as reinforcements that inhibit deformation, while the alloy's internal structure accommodates stress through consistent slip behavior, regardless of temperature. ..."
From the highlights and abstract:
"This study introduces the concept of ‘Hyperadaptor’ alloys, materials engineered to maintain consistent performance across a wide range of environmental conditions.
We present a Ni-based high-entropy alloy (HEA) that exhibits minimal sensitivity to temperature variations from 77 K to 873 K, maintaining both strength and ductility due to nano-sized L12 precipitates, coarse grain, and high stacking fault energy. The temperature-independent mechanism of dislocation slip-induced plasticity further supports its stability. Our findings highlight the potential of Ni-based HEA for demanding applications in aerospace, automotive, and energy sectors, establishing them as pioneering materials in alloy development.
HIGHLIGHTS
- Introduces the concept of ‘Hyperadaptor’ materials, which exhibits minimal environmental sensitivity, and demonstrates Ni-based high-entropy alloys (HEAs) as prime examples, showing consistent mechanical properties across a wide temperature range from 77 K to 873 K.
- Demonstrates minimal temperature sensitivity of Ni-based HEA through analyses of nano-sized L12 precipitates and high stacking fault energy, enhancing strength and ductility.
- Employs various characterization techniques, including EBSD, ECCI, and TEM, to illustrate the dislocation slip-induced plasticity and precipitation hardening, achieving temperature-independent mechanical performance.
- Validates the potential of Ni-based HEAs for critical applications in the aerospace, automotive, and energy sectors, emphasizing their consistent mechanical properties under extreme temperature fluctuations.
"
A new super metal stands strong, no matter the temperature (original news release)
Hyperadaptor; Temperature-insensitive tensile properties of Ni-based high-entropy alloy a wide temperature range (open access)
Graphical abstract
No comments:
Post a Comment