Mechanical Behavior

Abstract
To improve automobile fuel efficiency and reduce emissions, there has been a growing demand for more durable alloys for engine components with improved high temperature fatigue resistance. This study examined the effect of alloying elements on the high temperature mechanical behavior of Al-Si-Mg-(Cu) casting alloys for diesel cylinder heads. Depending..... More

Abstract
In this study, the effect of microstructural factors on the impact toughness of hypoeutectoid steels with ferrite-pearlite structure was quantitatively investigated using multiple regression analysis. Microstructural analysis results showed that the pearlite fraction increased with increasing austenitizing temperature and decreasing transformation temperature which substantially decreased the pearlite interlamellar spacing and..... More

Corrosion & Surface Treatment

Abstract
Pure Mg, Mg-5wt%Ca, and Mg-5wt%Ca-1wt%Zn alloys were cast, and their high-temperature oxidation behavior was investigated to determine the roles of Ca and Zn in oxidation. Ca and Zn additions refined the microstructure by formation of Mg₂Ca and Ca₂Mg₆Zn₃, respectively, at grain boundaries. Ca increased the oxidation resistance by forming a..... More

Abstract
In this study, the effect of potassium persulfate on current efficiency for gold plating was investigated using electrochemical techniques. The current efficiency in the low-current-density range greatly decreased when potassium persulfate was added to the gold plating solution. However, the current efficiency in the high-current-density range did not change with..... More

Casting/Solidification/Heat Treatment

Abstract
As a first step to optimizing the homogenization heat treatment following high temperature upset forging, the solidification segregation and the homogenization behaviors of solute elements were quantitatively analyzed for 1Cr-1.25Mo-0.25V steel ingot by electron probe micro-analysis (EPMA). The random sampling approach, which was designed to generate continuous compositional profiles of..... More

Electronic Materials

Abstract
In this study the effects of Bis(3-Sulfo-Propyl)di-Sulfide (SPS) on the elongation, surface morphology and crystal structure of electrolytic copper foil were investigated. Additives HEC (hydroxyethyl cellulose) (A), SPS(B), Coll-A(C) were used in the study, and the additive used as D was a Cl- ion. The study results show that there..... More

Composite Materials

Materials Analysis & Characterization

Abstract
Experimental techniques for serial sectioning and reconstruction were investigated in the three-dimensional imaging of microstructures in metallic materials. Mechanical polishing equipped with a light optical microscope and a digital image processor was used for the serial sectioning and reconstruction. Different processing conditions were investigated for three different alloys: Al-Si alloy,..... More

Abstract
Micro-twinning has been investigated in some state-of-the-art materials by transmission electron microscopy, but such characterizations have not been clear so far. Micro-twins must be characterized by identifying their spots in the electron diffraction pattern, which is very unique compared to normal defects such as dislocations or stacking..... More