Nanometer copper, if cold-rolled at room temperature, can extend from 1 centimeter to 1 meter and its thickness can be reduced to 20 micrometer from 1 millimeter. A research team from the Chinese Academy of Sciences discovered this special property of nanometer metal, marking a great breakthrough in the study of nanometer material.
An article about this discovery has been published in the authoritative magazine Science and received widespread praise. The German scientist H. Gleiter, creator of nanometer material, deemed the research a breakthrough in the field. He said that this shows people how seamless nanometer material changes its shape.
Metals usually break or crack while being processed. How to make a highly plastic metal endure large changes but not break is a tough problem for scientists of all countries. Ten years ago, Professor H. Gleiter predicted that if the crystalline grain which constitutes a metal could be reduced to one nanometer, the metal would have great plasticity and ability to change shapes.
For many years, although computer models concurred with Professor Gleiter's theory, the scientists' experiment results were disappointing. Big seams, small density and being polluted, were all factors that caused the nanometer copper to crack while being cold-rolled.
By using a new technique, Lu Ke, a research member of the group, has synthesized high density, highly pure nanometer copper. Its crystallite grain dimension is only 30 nanometers, one-ten thousandth of common copper.
Experts say that this discovery has closed the gap between nanometer material and the practical use. It will have great value to the production of sophisticated processing, electronic instruments, micro-machines.
Nanometer material is one of the most cutting edge technology in the world. In the past 10 years, the Chinese research team has achieved a series of results and discoveries and been called one of the six most outstanding teams in the world. Lu Ke is the sole Chinese member on the international nanometer materials committee.
(People's Daily)
