China scientists create unbreakable diamond

The material, developed by researchers from the Chinese Academy of Sciences' Institute of Physics and Beihang University, addresses one of diamond's biggest weaknesses: its brittleness.

Diamond is the hardest naturally occurring material and is widely used in cutting, drilling and polishing tools. However, like glass, it can fracture under a sharp impact. Attempts to make diamond tougher have typically reduced its hardness.

The Chinese team found a way around that trade-off by reinforcing diamond with multi-walled carbon nanotubes, according to a study published in the peer-reviewed journal Nature Synthesis on July 9, the South China Morning Post reported.

A person holds a 2,492-carat diamond found in Botswana. Photo by Lucara Diamond Corp

The nanotubes essentially act like steel bars reinforcing concrete. They form an internal support network that absorbs force and prevents cracks from spreading rapidly, making the diamond harder to break without reducing its hardness.

Laboratory tests showed the new material was five to six times tougher than conventional diamond while retaining roughly the same hardness. Its toughness also surpassed that of typical tungsten alloys used in armor-piercing ammunition.

The material could eventually be used in super-hard cutting tools, geological drill bits and aerospace components that need to withstand heavy impacts and extreme wear.

The breakthrough comes as synthetic diamonds find new uses beyond jewelry and traditional industrial applications, particularly in the rapidly expanding artificial intelligence industry.

China's lab-grown diamond producers are benefiting from rising demand in advanced chipmaking, where diamonds are increasingly being used to dissipate heat from powerful AI semiconductors, Bloomberg reported in June.

Analysts said diamond is increasingly viewed as a better alternative to traditional cooling materials such as copper and aluminum, with its use expected to expand across AI chips and data centers.