Magnesium alloys are of emerging interest in the automotive, aerospace and electronic industries due to their light weight, high specific strength, damping capacity, etc. However, practical applications are limited because magnesium alloys have poor formability at room temperature due to the lack of slip systems and the formation of basal texture, both of which characteristics are attributed to the hcp crystal structure. Fortunately, many magnesium alloys, even commercialized AZ or ZK series alloys, exhibit superplastic behavior and show very large tensile ductility, which means that these materials have potential application to superplastic forming (SPF) of magnesium alloy sheets. The SPF technique offers many advantages such as near net shaping, design flexibility, simple process and low die cost. Superplasticity occurs in materials having very small grain sizes of less than 10 μm and these small grains in magnesium alloys can be achieved by thermomechanical treatment in conventional rolling or extrusion processes. Moreover, some coarse-grained magnesium alloys are reported to have superplasticity when grain refinement occurs through recrystallization during deformation in the initial stage. This report reviews the characteristics of superplastic magnesium alloys with high-strain rate and coarse grains. Finally, some examples of SPF application are suggested.

Porous metals are called as a new material of 21th century because they show not only extremely low density, but also novel physical, thermal, mechanical, electrical, and acoustic properties. Since the late in the 1990‘s, considerable progress has been made in the production technologies of many kinds of porous metals such as aluminum, titanium, nickel, copper, stainless steel, etc. The commercial applications of porous metals have been increased in the field of light weight structures, sound absorption, mechanical damping, bio-materials, thermal management for heat exchanger and heat sink. Especially, the porous metals are promising in automotive applications for light-weighting body sheets and various structural components due to the good relation between weight and stiffness. This paper reviews the recent progress of production techniques using molten metal bubbling, metal foaming, gas expansion, hollow sphere structure, unidirectional solidification, etc, which have been commercialized or under developing, and finally introduces several case studies on the potential applications of porous metals in the area of heat sink, automotive pannel, cathod for Ni-MH battery, golf putter and medical implant.

Recently, consumption of magnesium alloys has increased especially in the 3C (computer, communication, camera) and automobile industries. The structural application of magnesium alloys has many advantages due to their low densities, high specific strength, excellent damping and anti-eletromagnetic properties, and easy recycling. However, practical application of these alloys has been limited to narrow uses of mild condition, because they are inferior in corrosion resistance and wear resistance due to their high chemical reactivity and low hardness. Various wet and dry processes are being used or are under development to enhance alloy surface properties. Various conversion coating and anodizing methods have been developed in a view of eco-friendly concept. The conventional technologies, such as diffusion coating, sol-gel coating, hydrothermal treatment, and organic coating, are expected to be newly applicable to magnesium alloys. Surface treatments for metallic luster or coloring are suggested using the control of the micro roughness. This report reviews the recent R&D trends and achievements in surface treatment technologies for magnesium alloys.

We developed a 3D simulation model of microstructure evolution of vertically aligned porous structure due to phase separation during film growth. The model proves its validity by reproducing the results of previous researches which are topological features of the microstructures and effects of varied processing parameters. The model will be extended by including bulk diffusion effect and elastic effect.

홍게를 데친 가공액을 pH 4.0로 침전시켜 분리 단백질을 제조한 후 기능성 즉, 용해도, 유화력 및 유화 안정성을 pH와 염농도 등을 달리하여 콩 단백질과 비교 측정하였다. 단백질 용해도는 홍게 단백질과 비교구로 사용된 콩 단백질 모두 pH 4.0에서 가장 낮았고, pH 2.0와 pH 8.0 이상에서는 크게 증가하였다. 0.5M NaCl 첨가시는 홍게 단백질과 콩 단백질 모두 전 pH 범위에서 단백질의 용해도가 감소하였다. 유화력은 각 시료 단백질의 등전점 부근에서 가장 낮았고 단백질 농도가 증가할수록 유화력도 증가하였다. 유화 안정성은 유화력과 비슷한 크기로 나타나, 80℃에서 30분 가열하여도 안정하였다. 수분 흡착력은 콩 단백질이 우수한 반면 유지 흡착력은 홍게 단백질이 더 우수하였다.