Papers by Author: Kazumi Minagawa

Abstract: The Expandable Mica was Modified with a Melamine Hydrochloride Salt at 60°C for Three Hours. the Resulting Melamine-Modified Mica (MME) was Melt-Kneaded with Polyamide 6 (PA6) Using a Twin-Screw Kneader at 250°C. the Addition of MME to the PA6 Matrix Resulted in a Finer Dispersion, as Evidenced by the Disappearance of the (001) Reflections in the XRD Patterns and TEM Image. the Tensile Modulus of MME/PA Nanocomposite (including 4.1 Mass % Mica) Increased by Approximately 1.8 Times Compared with that of the Neat PA6, which can be Attributed to the Increasing of the Exfoliated Silicate Platelets and the Dominating of the γ Crystalline Form in the Nanocomposites.

Abstract: In this research, the effect of the aluminum addition to cast iron on damping property was investigated by central vibration method, dynamic mechanical analysis, ultrasonic attenuation measurement and impact sound method. All measurement results indicated that the addition of aluminum improve the damping property of cast iron.

Abstract: Fabrication of nano-laminar ceramic composite by a simple sintering technique was examined. Glass flakes with a thickness of 0.7μm coated with silver were used as model materials, and were consolidated by pulsed current sintering with a uniaxial press of 7.1MPa or 30MPa. By sintering the flakes at 943K, we obtained a fairly dense composite where the flakes were aligned by uniaxial press. The silver coating remained on the flakes through the sintering, and an interface layer between the flakes was formed. The sample’s indentation test demonstrated its high resistance to crack propagation through the transverse direction of the lamellar; this result was attributed to crack deflection at the interface and the accumulation of microfractures around the indentation mark.

Abstract: Hybrid atomization is a new atomization technique that combines gas atomization with centrifugal atomization. This process can produce fine, spherical powders economically with a mean size of about 10 μm diameter and a tight size distribution. Experiments on the process were carried out using a Sn-9 mass% Zn alloy to investigate the influence of processing parameters on powder characteristics in hybrid atomization. The primary atomization mechanism under normal hybrid atomization conditions is predicted to be direct drop formation mode.