Ceramic materials are not only strong but also very durable. They are more resistant to scratches than glass, and resistant to high temperatures than most metals. The use of ceramics can effectively protect electronic equipment under extreme conditions.
It is precisely because ceramics are very hard that processing is also very difficult. To seal the two ceramic plates together, they need to be heated to a high temperature above 2000°C, which usually damages the embedded electronic devices. Today, researchers have developed a welding technique that can point-heat ceramics by laser. Related research was published in the journal Science.
The specially modulated laser can heat the irradiated point to melt the glass. However, unlike glass which absorbs light, ceramics have a scattering effect on light. Ceramic products have tiny light scattering holes in the structure, so they will appear opaque. Javier E. Galai, principal researcher of mechanical and aeronautical engineering at the University of California, San Diego, said: “When you talk about ceramics, you usually think of a coffee cup or a bowl.”
Sixty years ago, ceramic scientist Robert Cobble proposed the idea of adjusting the production process to reduce the size and number of pores in order to achieve transparency or translucency of ceramic materials.
Now, using translucent ceramics and laser technology similar to glass welding, researchers can weld cylindrical ceramic containers to shape. The gap after welding is very tight, which can prevent air leakage and maintain the vacuum state of the equipment.
This can completely guarantee its use in harsh environments such as space. In addition, ceramics do not react with living tissues, so they can also be used to package electronic devices implanted in the human body.
"This is a major engineering achievement," said Shimashu Hain, a materials scientist at Lehigh University. Although there have been previous studies using lasers to melt ceramics, this is the first time that a laser has been used to weld ceramic blocks together.