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Change of optical properties and microstructure of an Ag-Pd-In alloy according to Ag content

Ag의 함량에 따른 Ag-Pd-In계 합금의 광학적 특성 및 미세구조의 변화

  • Seol, Hyo-Joung (Department of Dental materials, School of Dentistry, Pusan National University) ;
  • Cho, Su-Yoen (Department of Dental materials, School of Dentistry, Pusan National University) ;
  • Cho, Mi-Hyang (Department of Dental Lab, Wonkwang Health Science University)
  • 설효정 (부산대학교 치의학전문대학원 치과재료학교실) ;
  • 조수연 (부산대학교 치의학전문대학원 치과재료학교실) ;
  • 조미향 (원광보건대학교 치기공과)
  • Received : 2018.08.21
  • Accepted : 2018.09.14
  • Published : 2018.09.30

Abstract

In this study, change of optical properties and microstructure of an Ag-Pd-In alloy according to Ag content was investigated. For this purpose, specimen alloys were prepared by adding 0-100 wt.% of Ag to the 50Pd-50In (wt.%) alloy. When the content of Ag was more than 40 wt.%, the color difference with pure gold specimen was increased(p<0.001). L* value increased as the Ag content of the specimen increased, but a* and b* value increased until the addition of 20 wt.% Ag, and then decreased with increasing Ag content(p<0.001). Ag-free specimen was single phase in the as-cast state, but when the content of Ag was more than 20 wt.%, the phase separation occurred and two phases of matrix and dendrite or granular structure were confirmed. The dendrite or granular structure was composed of the InPd phase, and the matrix was composed of the Ag-rich phase. From these results, it can be concluded that the specimens with Ag content of 20-70 wt.% have the Ag-rich matrix which has a high L* value and low a* and b* value, and have the dendrite structure which has a low L* value and high a* and b* value. As the content of Ag increased, the color changed from light yellow to silver white due to the increase in the ratio of the matrix to the dendrite or granular structure.

본 연구에서는 Ag-Pd-In계 합금에서 Ag, Pd, In의 조성에 따른 색상의 변화를 규명하고자 Pd와 In을 중량비로 1:1로 하고, Ag의 함량을 0-100 wt.%로 변화시켜 시편을 제조하여 분광광도계로 광학적 특성을 측정하고 조성에 따른 광학적 특성의 변화 및 이와 관련된 미세구조의 변화를 조사하였다. 중량비로 1:1의 Pd-In 합금에서 Ag의 첨가량이 40 wt.% 이상일 경우 100 % Au 시편과의 색차가 점점 커지는 것으로 나타났다(p<0.001). 명도지수인 L*은 시편의 Ag의 함량이 높아질수록 증가하였다(p<0.001). a*와 b*는 Ag가 20 wt.% 까지 첨가된 경우 증가하였으나 Ag의 함량이 더 많아짐에 따라 점점 감소하였다(p<0.001). Ag가 함유되지 않은 시편은 주조상태에서 단일상 이었으나, Ag의 함량이 20 wt.% 이상인 경우, 상분리가 일어나 기지와 덴드라이트 혹은 입자형 구조를 이루는 2상이 확인되었다. 덴드라이트 혹은 입자형 구조는 InPd상이었으며, 기지는 Ag-rich상으로 이루어져 있었다. 이로부터 Ag 함량이 20-70 wt.%인 시편은 L*값이 높고 a*와 b*값이 낮은 Ag 기지와, L*값이 낮고 a*와 b*값이 높은 InPd 덴드라이트 구조가 합쳐진 2상 구조이며, Ag의 함량이 증가할수록 덴드라이트 구조에 대한 기지의 비율이 높아지면서 연한 노란색에서 은백색으로 색상이 바뀌었다.

Keywords

Acknowledgement

Supported by : 한국연구재단

References

  1. Callister JR WD (1985) Materials Science and Engineering: An Introduction. New York: John Wiley & Sons, Inc; pp.535-536
  2. Cho SY, Lee GY, Kwon YH, Kim HI, Seol HJ (2011). Age-hardening characteristic of a Cu-free Ag-Pd alloy containing high In. Kor J Dent Mater 38:91-100
  3. Cullity BD (1978) Elements of X-ray Diffraction. 2nd ed. Massachusetts: Addison-Wesley publishing; pp.506-507
  4. Hattori M, Tokizaki T, Matsumoto M, Oda Y (2010). Corrosion Properties of Ag-Au-Cu-Pd System Alloy Containing Indium. Bull Tokyo Dental Coll 51:7-13 https://doi.org/10.2209/tdcpublication.51.7
  5. Kim HS, Dzo MH, Lee KH, Shin MC (2000). The corrosion and tarnish behavior of new palladium-indium system alloys. J Mater Sci 35:4989-4994. https://doi.org/10.1023/A:1004898829222
  6. Lee GY, Kim YO, Cho SY, Seol HJ, Kwon YH, Kim HI (2012). Age-Hardening Behavior of a Pd-Ag-In Alloy with Particle Structures. Kor J Dent Mater 39:103-110
  7. Lee HK, Moon HM, Seol HJ, Lee JE, Kim HI (2004). Age hardening by dendrite growth in a low-gold dental casting alloy. Biomaterials 25:3869-875 https://doi.org/10.1016/j.biomaterials.2003.10.037
  8. Massalski TB (1990). Binary alloy phase diagrams. 2nd ed. Materials Park: ASM International; pp.72-74
  9. Pyo AR, Shin HJ, Cho SY, Kwon YH, Kim HI, Seol HJ (2016). Change in Hardness and Microstructure During Porcelain Firing Simulation in a Pd-Ag-In-Au Metal-Ceramic Alloy. Kor J Dent Mater 43:57-66
  10. Seol HJ, Cho MH, Park MG, Kwon YH, Kim HI (2009). Age-hardening mechanism in a dental casting Ag-Au-Pd-In-Zn alloy. Kor J Dent Mater 36:89-96.
  11. Shiraishi T and Geis-Gerstorfer J (2006). Optical Properties of Au-Pt-Pd-based High Noble Dental Alloys. Gold Bulletin 39:9-15 https://doi.org/10.1007/BF03215527
  12. Shiraishi T, Takuma Y, Fujita T, Miura E, Hisatsune K (2009). Optical properties and microstructures of Pd-free Ag-Au-Pt-Cu dental alloys. J Mater Sci 44:2796-804 https://doi.org/10.1007/s10853-009-3368-0
  13. Shiraishi T, Takuma Y, Miura E, Tanaka Y, Hisatsune K (2003). Factors affecting the optical properties of Pd-free Au-Pt-based dental alloys. J Mater Sci : Mater Med 14:1021-1026 https://doi.org/10.1023/B:JMSM.0000003997.45001.2e
  14. Villars P and Calvert LD (1985). Pearson's handbook of crystallographic data for intermetallic phases. Metals Park: American Society for Metals; p.3027