Source: Guangming Daily
Did you know? Metals can also suffer from "chronic diseases"!
The blades of aircraft engines withstand tens of thousands of high-temperature impacts per second, and the cables of sea-crossing bridges bear millions of tons of weight day after day – these components of "national heavyweights" are silently enduring a kind of torture called "ratcheting damage." Just like people who get sick from overwork, metals develop irreversible damage internally after repeated stress, which may ultimately lead to catastrophic fractures.
In order to tackle the unstable problems of metal materials, Chinese researchers have come up with an ingenious solution: they are "weaving" a three-dimensional "anti-collision wall" at the submicron scale for metals!
On April 2nd, in the laboratory of the Shenyang National Research Center for Materials Science of the Institute of Metal Research, Chinese Academy of Sciences, researchers are preparing to place processed metal material samples into a scanning electron microscope to observe structural changes. Photo by Zou Xiaozhen, reporter of Guangming Daily.
This breakthrough was published online on April 4th at midnight in the journal Science by the team led by Dr. Lu Lei from the Institute of Metal Research, Chinese Academy of Sciences. They imitated the principle of "twisting hemp rope" to construct unique "gradient structured dislocation cell structures" inside 304 austenitic stainless steel through special processes. Simply put, they have created countless "anti-collision walls" inside the metal!
How powerful are these "anti-collision walls"?
They absorb external force energy like springs;
They will "self-upgrade" when faced with strong impacts, forming a denser protective network;
They increase the material strength by 2.6 times;
They enhance the fatigue resistance of metal materials by over ten thousand times!
On April 2nd, in the laboratory of the Shenyang National Research Center for Materials Science of the Institute of Metal Research, Chinese Academy of Sciences, researchers are preparing to place metal samples into processing equipment. Photo by Zou Xiaozhen, reporter of Guangming Daily.
In the world of metals, there has always been an "impossible triangle": strength, ductility, and stability during use. These three characteristics are often difficult to achieve simultaneously. However, this time, the research results of Dr. Lu Lei's team have made the impossible possible! "We have effectively equipped metal materials with 'nano shock absorbers' that self-reinforce," Dr. Lu Lei vividly explained. "Moreover, the entire strengthening process occurs uniformly without localized deformation leading to damage. Compared to the raw material, the processed metal material shows almost no difference in appearance."
On April 2nd, in the laboratory of the Shenyang National Research Center for Materials Science of the Institute of Metal Research, Chinese Academy of Sciences, Dr. Lu Lei is demonstrating the processed and unprocessed metal material samples. Although there is no visible difference on the surface, the internal structure has changed. Photo by Zou Xiaozhen, reporter of Guangming Daily.
This achievement also provides a brand-new solution for engineering safety in fields such as aerospace and major infrastructure. This means that our aircraft engines can become more durable, sea-crossing bridges safer, and the service life of spacecraft longer.
"This achievement has the potential for widespread application in various engineering alloy materials, and it is expected to provide important support for the long-term and reliable operation of critical components under extreme conditions such as aerospace," Dr. Lu Lei展望ed.
(Reporters Zou Xiaozhen and Liu Yong of the Guangming Daily全媒体)
Original article: https://www.toutiao.com/article/7489632890797326875/
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