Papers by Author: Han Gil Suk

Abstract: This study examined the application of color measurement to determining the chemical composition of Cu alloys such as Cu-Zn, Cu-Sn, and Cu-Al using a color recognition system. Measured data showed that the hue intensity changed exponentially when Zn, Sn, or Al in the Cu binary systems and fitted well with an exponential equation within the experimental error. This indicates that the obtained equations can be used for predicting the compositions of Cu-Zn, Cu-Sn, and Cu-Al systems by measuring the hue intensity.

Abstract: This work focuses on the strain states of the mid AA 3003 strip sandwiched in between either AA 3003 sheets or STS 430 sheets. For that purpose, the strain states at various through-thickness layers were analyzed by measurements of crystallographic texture and by simulations with the finite element method (FEM). During sandwich rolling, the material property of outer sheets of sandwich samples played an important role in the evolution of the strain states and the corresponding texture formation. In the mid AA 3003 sheets, rolling with the harder outer sheets gave rise to pronounced through-thickness texture gradients, whereas fairly uniform strain states prevailed during rolling with the outer sheets of the same AA 3003.

Abstract: Grain growth in the cold rolled and subsequently recrystallized AA 5182 sheets was investigated by means of microstructure observations and texture measurements. Grain growth behavior strongly depends on the annealing temperatures. Grain growth hardly took place at temperatures lower than 470°C, which is attributed to a low mobility of grain boundaries. Abnormal grain growth occurred at temperatures ranging from 480 to 530°C. Annealing above 560°C gave rise to the dissolution of inhibitor precipitates, which led to normal grain growth.