TiAl Alloy
The Korea Institute of Materials Science announced on Feb. 2 that its research team headed by professors Kim Seung-eon, Na Young-sang, and Kim Sung-woong has developed an improved turbocharger wheel for engine output.
At present, turbocharger wheels are made mainly of nickel alloys and are heavy while consuming a lot of fuel. The titanium/aluminum alloys in use abroad are complex in structure and show little room-temperature ductility in a cast state, which has led to difficulties in defect prevention and mass production.
However, the newly-developed titanium/aluminum alloy is lightweight and resistant to high temperatures, and can be used in gasoline vehicles with a temperature of over 900 C, unlike existing alloys. In addition, the wheel has a strength of 673 Mpa at room temperature and 568 Mpa at high temperature. It is also resistant to corrosion and has a high level of room-temperature ductility and productivity. Relatively inexpensive elements form the alloy, and thus supply is possible at a much cheaper price.
The institute has developed prototypes of the turbocharger wheel with investment casting companies. It is planning to come up with techniques for mass production in the latter half of this year.