The US invented the new method of processing metallic glass to make "spare parts".
Science and technology daily
according to the American physicist organization network recently reported that metal glass is widely used, but the cost of making parts with it is high, and it is easy to leave defects. Now, American scientists have developed a new technology called rapid spark molding, which can produce metal glass parts with flawless and different shapes at a low cost and quickly. William Jason, the leader of the project and professor of engineering and applied science of California Institute of Technology, said in the journal Science, published in 13, that the new method will completely change the face of the field of metallurgy.
1960, California Institute of Technology scientists first discovered metal glass, metal glass has both the advantages of metal and glass, and overcome their respective disadvantages, the strength is 3 times the strength of industrial steel, flexibility is 10 times the iron and steel, widely used in aerospace and consumer electronics and other fields.
metal glass, when used to make useful parts, must be heated to about 500 degrees Celsius to soften and become thick liquid to be molded. But in a thick liquid, the atoms of metal glass will soon spontaneously "go to each of you" to form crystals and avoid its rapid crystallization as a major challenge in the manufacture of metal glass parts.
previously, metal glass parts were made mainly by heating the metal glass to the melting point of the crystalline phase (generally more than 1000 degrees Celsius). Molten metal glass is put into an iron mold to cool before crystallization. But there is a problem: iron mold generally can only withstand the temperature of about 600 degrees Celsius, so it needs to be replaced frequently, which greatly increases the production cost. Moreover, at 1000 degrees Celsius, liquid metal glass has strong fluidity and is easy to splash, so that the final parts are "scarred".
the Jason team has opened up a new path to heat and process metal glass at an extremely fast speed. They only heat the solid metal glass to about 500 degrees Celsius, making it fluidity enough to inject into a mold and cool down the liquid state, everything happens before the crystal of the metal glass.
the Jason team uses resistance heating technology to heat the material evenly and quickly. In about 1 microseconds, they send a short and dense current pulse to a small metal glass rod to transmit 1000 joules of energy to heat it. The current pulse uniformly heated the entire metallic glass, which was more than 1000 times faster than before. In half a microsecond, Jason said, the metal glass reached the right temperature. Then, the metal glass in the molten state was injected into the mold and cooled, taking only a few microseconds. Using this new technology, the
Jason team successfully heated a metal glass rod into a circular object at 550 degrees Celsius and less than 40 microseconds. The new ring was unflawed and was not oxidized.
scientists can use new technology to study the metal glass in the molten state, for example, by heating it before it crystallizes, scientists can take a few microseconds to see the crystallization process. The new technology has been applied for patent and is now entering commercial production.