We prepared 8 samples of non-silver and silver-added master alloys containing silicon to confirm the existence of nickel-silicides. We then prepared products made of 14K and 18K white gold by using the prepared master alloys containing 0.25, 0.35, and 0.50 wt% silicon to check for nickel release. We then employed the EN 1811 testing standard to investigate the nickel release of the white gold products, and we also confirmed the color of the white gold products with an UV-VISNIR- color meter. We observed NiSix residue in all master alloys containing more than 0.50 wt% Si with EDS-nitric acid etching. For the white gold products, we could not confirm the existence of NiSix through XRD after aqua regia etching. In the EN 1811 test, only the white gold products with 0.25 wt% silicon master alloys successfully passed the nickel release regulations. Moreover, we confirmed that our white gold products showed excellent Lab indices as compared to those of commercial white gold ones, and the silver-added master alloys offered a larger L index. Our results indicate that employing 0.25 wt% silicon master alloys might be suitable for white gold products without nickel-silicide defects and nickel release problems.

1. 서 론
 2. 실험 방법
 3. 실험 결과
 4. 결 론
 감사의 글
 References

• 송정호(서울시립대학교 신소재공학과) | Jeongho Song
• 노윤영(서울시립대학교 신소재공학과) | Yunyoung Noh
• 이현우(서울시립대학교 신소재공학과) | Hyeonwoo Lee
• 최민경(서울시립대학교 신소재공학과) | Minkyoung Choi
• 송오성(서울시립대학교 신소재공학과) | Ohsung Song Corresponding author