In this study, the effects of powder size and composition on the reflectance of Al-Si based alloys are presented. First, the reflectance of Al-Si bulk and powder are analyzed to confirm the effect of powder size. Results show that the bulk has a higher reflectance than that of powder because the bulk has lower surface defects. In addition, the larger the particle size, the higher is the reflectance because the interparticle space decreases. Second, the effect of composition on the reflectance by the changing composition of Al-Si-Mg is confirmed. Consequently, the reflectance of the alloy decreases with the addition of Si and Mg because dendrite Si and Mg2Si are formed, and these have lower reflectance than pure Al. Finally, the reflectance of the alloy is due to the scattering of free electrons, which is closely related to electrical conductivity. Measurements of the electrical conductivity based on the composition of the Al-Si-Mg alloy confirm the same tendency as the reflectance.

Abstract
 1. 서 론
 2. 실험 방법
 3. 결과 및 고찰
  3.1. 형태에 따른 Al-12Si 합금의 반사율
  3.2. 조성에 따른 Al-Si-Mg 합금의 반사율
 4. 결 론
 References

• 최광묵(고등기술연구원 신소재공정센터) | Gwang Mook Choi (Center for Advanced Materials and Processing, Institute for Advanced Engineering)
• 채홍준(고등기술연구원 신소재공정센터) | Hong Jun Chae (Center for Advanced Materials and Processing, Institute for Advanced Engineering) Corresponding Author