Highly durable airgel could eventually become a spacecraft insulation upgrades

Ultra-high temperature ceramic materials! Highly durable airgel could eventually become a spacecraft insulation upgrade 高度耐用的气凝胶最终可能成为航天器绝缘的升级 collaborators at UCLA researchers and eight other research institutions have created a very light, very durable ceramic airgel. Such materials may be used for thermal insulation applications such as spacecraft, space missions because it can withstand high temperatures and are subjected to severe temperature changes. Since the 1990s, ceramic airgel has been used to isolate industrial equipment, and scientific equipment is used to isolate the NASA Mars rover missions. But the new version is more durable under extreme heat and repeated temperature peaks environment, much lighter in weight. Its unique atomic composition and microstructure having elastically also unusual. When it is heated, the material shrinks rather than expands like other ceramics. It is also perpendicular to the direction of compression shrinkage – imagine a tennis ball put pressure on the table, so that inward movement of the center of the ball, rather than outward expansion – this reaction is most compressed when the material is opposite. Therefore, this material is more flexible than the most advanced ceramic airgel, shatterproof: it can be compressed to 5% of its original volume and fully restored, while other existing airgel can only be compressed to about 20%, then full recovery. Although they are more than 99% by volume of air, but aerogels are solid, they are comparable in structure weight. They may be made of various materials, including ceramics, carbon or metal oxides. Compared with other insulators, ceramics based aerogels having advantages in the barrier extreme temperatures, and they have a very low density, highly refractory and corrosion – all of these properties are suitable for reusable spacecraft. But the ceramic airgel is very fragile, easily broken in after repeated exposure to extreme heat and extreme temperature fluctuations, both of which are common in space travel. The new material is a thin layer of boron nitride (a ceramic material) of the composition, in the form of a hexagonal atom together like as barbed wire. In the study, it has withstood the often destroy other airgel conditions. When the temperature of engineers in just a few seconds to test the vessel was increased or decreased to between zero to minus 198 degrees Celsius to 900 degrees Celsius, it withstood hundreds of sudden extreme temperature peaks. In another test, which at 1400 ° C after one week storage, the mechanical strength is decreased less than 1%. The key new ceramic airgel is its durabilityUnique structure, its inherent flexibility to help it withstand extreme heat and thermal shock of shocks, these shocks will lead to failure of other ceramic airgel. Common ceramic material generally expands when heated and contracts when cooled. Over time, the repeated temperature changes can cause these materials fracture and ultimately fail. The new airgel is designed on the contrary, it shrinks rather than expands when heated, and therefore more durable. In addition, airgel is perpendicular to the direction of compressive shrinkage ability – as in the example of tennis, like – to help it survive the repeated rapid changes in temperature. (This property is called negative Poisson\’s ratio) it also has internal \”wall\”, reinforced by a double glass structure, which reduces the weight of the material, while increasing its insulation capacity. Manufacturing process developed by researchers at the new airgel can also be used to manufacture other ultra-lightweight materials. These materials can be used for thermal insulation spacecraft, automobile or other special equipment. They can also be used for thermal energy storage, catalysis or filtration.

相关新闻