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REPORTAGE - HANA ITM INC.
The next logical step HANA ITM INC, which was established in 2003 and based in South Korean Gimhae-si, is specialized in the production of parts for the aviation industry. To begin with, the focus was on honeycomb seals and shrouds for gas turbines, but then the company developed a new process for the production of lowpressure turbine nozzles. An interview with CEO Steve Yoon. EROWA: Mr. Yoon, you played a key role in the development of the new process. Can you explain it in more detail? STEVE YOON: “It’s a 5-axis CBN creep-feed grinding process. The work-pieces are LPT guide vanes – LPT stands for lowpressure turbine. Our process machines the nozzle components that are needed for this part. In contrast to classical grinding, the process has the advantage thata grinding wheel is used in which a great deal of material can be removed without burr formation, this results in a big cutting depth. Also, the process is faster, and we get a good surface quality. The grinding wheel consists of diamonds and cubic boron nitride (CBN), which
is the hardest known abrasive. We need this, because the workpieces themselves are highly resistant since they have to withstand extremely high temperatures.” It probably wasn’t all that easy to develop this process? “To tell you the truth, it was a big challenge for all of us. We developed, tested and re-adapted intensively for two years… and the entire solution required substantial investments. There are countless ways of machining turbine nozzles, and the methods vary from company to company. The machining technology of 5-axis CBN creep-feed grinding provided the break-through for the efficient grinding of the radial grooves of turbine nozzles. We’re very proud of this, and we’re the only ones in Korea who are able to do this. It was also a very crucial step that the machine producer DOOSAN modified its DNM350 5ax with special grinding equipment for us, for this machine type is really a milling machine, but we use the machine for this creepfeed grinding process.