This study investigates the interfacial reaction between powder-metallurgy high-entropy alloys (HEAs) and cast aluminum. HEA pellets are produced by the spark plasma sintering of Al0.5CoCrCu0.5FeNi HEA powder. These sintered pellets are then placed in molten Al, and the phases formed at the interface between the HEA pellets and cast Al are analyzed. First, Kirkendall voids are observed due to the difference in the diffusion rates between the liquid Al and solid HEA phases. In addition, although Co, Fe, and Ni atoms, which have low mixing enthalpies with Al, diffuse toward Al, Cu atoms, which have a high mixing enthalpy with Al, tend to form Al–Cu intermetallic compounds. These results provide guidelines for designing Al matrix composites containing high-entropy phases.

For the development of a low-melting point filler metal for brazing aluminum alloy, we analyzed change of melting point and wettability with addition of Sn into Al-20Cu-10Si filler metal. DSC results showed that the addition of 5 wt% Sn into the Al-20Cu-10Si filler metal caused its liquidus temperature to decrease by about 30 oC. In the wettability test, spread area of melted Al-Cu-Si-Sn alloy is increased through the addition of Sn from 1 to 5 wt%. For the measuring of the mechanical properties of the joint region, Al 3003 plate is brazed by Al-20Cu-10Si-5Sn filler metal and the mechanical property is measured by tensile test. The results showed that the tensile strength of the joint region is higher than the tensile strength of Al 3003. Thus, failure occurred in the Al 3003 plate.

In this study, fundamental properties and change with time of cement mortar accompanied with change of solid content ratio of PC type superplasticizer were analyzed. As a result, it was clarified that the flow and air content decreased as the solid content ratio decreased, and the compressive strength increased slightly.

The purpose of this study is to analyze the crack characteristics of concrete by comparing the previously developed transparent bubble sheet and the aluminum deposited bubble sheet whose surface is exposed by applying to the walled structure apartment actually constructed. The aluminum deposited bubble sheet was developed for the purpose of temperature reduction through heat reflection.

In previous research team had reported that the durability of carbonation is improved by filling voids due to the saponification reaction of oil and concrete. The purpose of this study was to have experimental investigation the effect of mock-up experiment on the carbonation resistance of the waste concrete admixture.

In previous research team had reported that the durability of carbonation is improved by filling voids due to the saponification reaction of oil and concrete. The purpose of this study was to have experimental investigation the effect of mock-up experiment on the carbonation resistance of the waste concrete admixture.

In the modern construction industry, some methods for enhancing the quality of a building have been sought in various ways. Accordingly, this research team intends to mutually compare the overall kinds of quality of products, such as, the temperature characteristics of PE films and the exposed surface, etc., by applying the single-layered bubble sheet that was developed as a surface curing material for summer to the construction site for a wall-type Apartment which is under construction.

In this study, we tried to review the potential of commercialization of the developed product of aerated concrete and floor mortar used in the construction of residential buildings such as apartment buildings. As a result, it was analyzed that the difference was negligent in terms of the depth of subsidence, though the developed product was good enough in terms of compressive strength and economic efficiency.