Papers by Author: Byung Geel Yu

Abstract: Deformation characteristics of a newly developed wave-typed heat sink during mechanical assembly of fin-base were analyzed by using the Ansys program. The original points a and b marked in the fin and base moved to the opposite y direction with increasing pressure, while their movements to x direction were relatively small. It was evident that at least 207㎫ must be applied to well bond the fin with the base. Under a constant pressure, the smaller the pressured area was, the better the bonding between fin and base was, despite a small uniform deformation in the base area as the pressured area increased.

Abstract: Plasma electrolytic oxide coatings were produced on both pure magnesium and binary Mg-Al alloys containing 3, 6, 7 wt% Al, and the effect of Al on the characteristics of coatings was investigated under the processing conditions of various coating times and current. The coatings on Mg-Al alloys showed porous microstructure and some volcano top-like pores on the surface, and they consist of MgO and Al2O3. The surface roughness became larger with increasing coating time, while it was unchanged with increasing Al content. The thickness increased with increasing coating time and showed slight dependence on Al content. The hardness was almost unchanged with increasing coating time and Al content in the coatings grown with the ratio of current, C1:C2=100:75.