You may have heard about a bit of winter that made its way though the south and northeast the last few days.

Here in Connecticut that bit was over two feet of snow.

The winter landscape in front of my condo. Mine is the one on the first floor.

1) Portraits from the Net

Boy by Levent Yavuz

Himba Chief by Gunnar Salvarsson

Untitled by Sergey Liamets

2) Science

U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the California Institute of Technology have developed a new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of any known material.

We are on the cusp of having available some amazing new materials, such as glass than steel and solar cells that can be applied to material as thin as toilet paper, that will revolutionize how we make the products we use and the energy we need to live with.

From the Berkeley Lab press release – http://newscenter.lbl.gov/news-releases/2011/01/10/new-glass-tops-steel/

The new metallic glass is a microalloy featuring palladium, a metal with a high “bulk-to-shear” stiffness ratio that counteracts the intrinsic brittleness of glassy materials.

Glassy materials have a non-crystalline, amorphous structure that make them inherently strong but invariably brittle. Whereas the crystalline structure of metals can provide microstructural obstacles (inclusions, grain boundaries, etc.,) that inhibit cracks from propagating, there’s nothing in the amorphous structure of a glass to stop crack propagation. The problem is especially acute in metallic glasses, where single shear bands can form and extend throughout the material leading to catastrophic failures at vanishingly small strains.

The lead researcher Robert Ritchie, “Because of the high bulk-to-shear modulus ratio of palladium-containing material, the energy needed to form shear bands is much lower than the energy required to turn these shear bands into cracks,” Ritchie says. “The result is that glass undergoes extensive plasticity in response to stress, allowing it to bend rather than crack.”

“Our game now is to try and extend this approach of inducing extensive plasticity prior to fracture to other metallic glasses through changes in composition,” Ritchie says. “The addition of the palladium provides our amorphous material with an unusual capacity for extensive plastic shielding ahead of an opening crack. This promotes a fracture toughness comparable to those of the toughest materials known. The rare combination of toughness and strength, or damage tolerance, extends beyond the benchmark ranges established by the toughest and strongest materials known.”

“Traditionally strength and toughness have been mutually exclusive properties in materials, which makes these new metallic glasses so intellectually exciting,” Ritchie says. “We’re bucking the trend here and pushing the envelope of the damage tolerance that’s accessible to a structural metal.”

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