A team of scientists has developed a new material that could change the construction of devices for space missions and other extremely cold environments. This new copper base retains its unique properties of the “form memory” even at temperatures such as -200 ° C.
Form memory alloys are fascinating materials that act like mechanical memory foam. When they are cold, they can be bent and twisted into different shapes. But if they are heated, remember their original shape and automatically snap back on it. This remarkable property makes it incredibly useful to create actuators that convert energy in machines in motion.
An example of the old school for an actuator that converts energy in motion within a DVD drive with lead screw and stepper engine. (Credit: Baran Ivo)
A good way to think about this concept is to imagine a thermostat in your house, which automatically adapts to the temperature or the mechanisms in space vehicles that have to move and adapt without human intervention. These applications are based on materials that can predictably react to temperature changes.
So far, form memory has been a major restriction in extreme cold. The most common type made from nickel and titanium stops working properly below -20 ° C. Some could work below -100 ° C at temperatures, but they were not practical for applications in the real world.
This created a real challenge for space technology, in which the devices are regularly exposed to temperatures far below -100 ° C. Space telescopes, satellites and other instruments need reliable moving parts that can work in the rough cold of the room.
Artist's impression of the James Webb World space telescope, which works as cold as -223 ° C at temperatures (loan: NASA)
The research team from several Japanese institutions, including Tohoku University and the Japan Aerospace Exploration Agency (JAXA), has developed the new copper-aluminum-manner alloy, which maintains its shape memory properties at extremely low temperatures. They successfully tested their alloy at -170 ° C, which showed that they could effectively control the heat transfer by switching between contact and non -contact states. This is great progress in materials science.
“We were very happy when we saw that it worked at -170 ° C, other form memory alloys simply can't do that” – Toshihiro Omori from the University of Tohoku.
With their new alloy, the researchers built a mechanical heat switch of prototypes. This device can automatically control the heat flow based on temperature changes. They found that the operating temperature of the alloy can be finished by adapting its composition, which means that it is adaptable for different applications. This flexibility could prove to be invaluable to develop devices for different space missions with different thermal requirements.
The simplicity and reliability of mechanical systems that use this alloy could make future space missions much reliable and at the same time reduce the complexity and weight of spatial vehicle systems. If space research extends and we venture into increasingly challenging environments, materials such as this new alloy will be of essential importance for building up the reliable equipment required for mission success.
Source: new cryogenic form memory alloy for space
