Chinese Scientists Create Gold with Tiny Holes for Enhanced Strength by 50 – 100%
A research team led by expert Jin Haijun at the Shenyang National Laboratory for Materials Science under the Chinese Academy of Sciences (CAS) has developed a new method for producing pure gold that is both durable and lightweight, as reported by Interesting Engineering on August 15. The new research was published in the journal Science.
Pure gold can be upgraded through new production techniques. (Photo: iStock).
Traditionally, metal shaping techniques such as casting, welding, and 3D printing are designed to eliminate internal bubbles in metals, as these are often considered material defects that reduce strength and damage surfaces. However, in this new research, instead of removing these bubbles, the team adjusted their size, shape, and distribution, which helped mitigate negative impacts and provided unexpected benefits.
The research team used gold as the sample material to develop the new technique, creating porous gold through a selective etching process. By compressing and then refining the metal, they produced a new material with nano-sized holes smaller than 100 nanometers scattered throughout.
Tests showed that adding nano holes with a volume ratio of 5 – 10% increased the strength of gold by 50 – 100%. This new material can bear greater loads while maintaining good ductility. In some cases, its ductility is even superior to that of solid gold of the same size.
“This enhancement is due to the dispersed nano holes that relieve stress and prevent stress concentration around the voids, thus preventing crack formation. The large specific surface area of the material promotes interaction between the surface and the defects, enhancing strength and the rate of deformation hardening – factors that contribute to increased ductility. The strategic positioning of the nano holes helps balance the strength and ductility of the material,” Jin explained.
The traditional method to increase strength typically involves adding lighter alloys like aluminum or lithium. The new method is environmentally friendly and cost-effective, upgrading metals without increasing weight or causing pollution.
The dispersed nano holes reduce the density of pure gold by over 10%, making gold lighter and recyclable. The new method also preserves essential physical and chemical properties of gold, such as thermal conductivity, electrical conductivity, and corrosion resistance. As a result, this method could significantly impact the aerospace, automotive, and consumer electronics industries, which are in dire need of durable and lightweight materials.
