변지영 심재동 2024-01-12T21:03:47Z 2024-01-12T21:03:47Z 1999-05-14 https://pubs.kist.re.kr/handle/201004/96623 희토류-철　합금의　제조방법 Patent 1999-05-14 1991-04-11 2926280 3-79087 JA 특허 한국과학기술연구원