New spray may extend life of cars, aircraft, ships

Korean engineers have developed a new cold spray coating system that could expand the service life of cars, aircraft, ships and semiconductors, the government said yesterday.
Developed jointly by Ajou University and Solmics Co., the system makes use of extremely high pressures and speed to cover an object with specially-made coating solutions, said the Ministry of Commerce, Industry and Energy. This is in contrast to the use of extreme heat employed in the conventional thermal spray method.
“The supersonic speed and pressure exerted in the spraying process allows the coating material to stick solidly to the surface of the item it is trying to cover,” said Yu Young-ho, chief engineer at Solmics.
Mr. Yu added that because of the relatively low heat and ordinary air used, the new system is about 30 percent cheaper to use, and has the added advantage of not distorting the material it is coating, enhancing durability.
“Under the cold spray system, the coating material is sprayed after being subjected to heat averaging 200-400 degrees Celsius, compared to the minimum of 3,000 degrees for the thermal spray that uses helium to facilitate the application,” he said. Mr. Yu added that tests have shown the quality of the coating remains unchanged for the lifespan of the product that has been covered in this method.
Conventional coating methods using arc and plasma sprays require the coating material to be heated to 3,000 degrees Celsius. This process causes oxidation and formation of air bubbles that compromise the quality of the finished product.
Mr. Yu said the company plans to begin mass production of the coating material and the mechanical system needed to apply it by the end of the year.
The Commerce Ministry provided 420 million won ($449,500) of the 590 million won used in the research and development of the project that was started in 2001. The domestic market for the new technology is estimated at 10 billion won per year.