The Korea Institute of Materials Science (KIMS, President Lee Jeong-hwan), a government-funded research institute under the Ministry of Science and ICT, has succeeded in localizing silicon nitride ceramic balls, a key component of electric vehicles currently monopolized by Japan, and expectations are high that this will open a way to overcome future dependence on Japan.

The Korea Institute of Materials Science recently announced that the research team led by Dr. Jae-Woong Ko of the Engineering Ceramics Laboratory has succeeded in localizing the manufacturing technology for silicon nitride bearing balls for electric vehicle drive modules. Its significance lies in overcoming the limitations of overseas dependence and opening up the possibility of domestic supply and demand.

Silicon nitride bearing balls have the advantages of preventing failure due to electrical erosion in the high output and high-speed rotation driving environments of electric vehicles, as well as high durability and reliability.

On the other hand, the problem of having to import everything from Japan has been continuously pointed out.

The supply of key components is an important issue that the government is considering as a key policy for responding to the reorganization of the global supply chain in 2022, starting with Japan's exclusion from the whitelist in 2019.

In the case of electric vehicles, the common opinion among automobile and bearing product manufacturers is that the supply of bearing balls, which are essential materials for bearing parts that rotate at ultra-high speeds of over 20,000 rpm, is not smooth.

The research team has developed technology to meet domestic demand, from silicon nitride raw material powder to materials and bearing ball parts.

Afterwards, by testing the technology through external accredited evaluation agencies and demand companies, we succeeded in implementing mechanical properties and expected life values close to those of Company T, the world's number one silicon nitride bearing ball company.

When the commercial balls of Company T and the balls manufactured by the research team were evaluated under the same conditions, the crushing strength, which is a performance indicator for withstanding load, showed a comparatively superior value of 103-105%, and in the case of the rolling fatigue life, which is a performance indicator for withstanding long-term high-speed rotation, a value at an equivalent level was obtained.

Silicon nitride bearing balls are used in fields requiring extreme operating environments, such as high-speed rotating hybrid bearings in electric vehicle drive modules, bearings for wind turbines subjected to high loads, ultra-high-speed bearings for semiconductor process pumps, and bearings for space and aviation.

The global market size of hybrid bearings using silicon nitride bearing ball technology is approximately It is worth 1 trillion won, and it is expected to increase to over 1.3 trillion won after 2026, driven by the rapid growth of the electric vehicle market.

“We believe that we have established a bridgehead for securing our own supply chain that can meet the domestic demand for silicon nitride bearing balls through future corporate technology transfer,” said Jaewoong Ko, a senior researcher at the Materials Research Institute who is in charge of the research. “We can expect not only the import substitution effect through localization, but also exports overseas.”

This research result was carried out through the basic project of the Korea Institute of Materials Science, 'Development of Ceramic Rolling Bearing Material for Semiconductor High Vacuum Pump Bearing' with the support of the Ministry of Science and ICT. The research team is currently transferring the technology to domestic medium-sized and strong companies with the infrastructure and capability to mass-produce domestic ceramic materials and parts, and through future mass production support, it aims to secure a domestic supply chain for silicon nitride bearing balls and hybrid bearings.