RISS 검색 - 국내학술지논문

1
Effect of Solidification Parameters on the Microstructure of Directionally Solidified Sn-Bi-Zn Lead-Free Solder

E. Çadlrll,U. Böyük,H. Kaya,N. Mara ll 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.2
Sn-Bi-Zn lead free solder alloy was directionally solidified upward at a constant temperature gradient (G=3.99K/mm) with a wide range of growth rates (8.3-478.6 µm/s) and at a constant growth rate (V=8.3 µm/s) with a wide range of temperature gradients (1.78-3.99 K/mm) using a Bridgman type directional solidification furnace. Wavelength-Dispersive X-ray Fluorescence spectrometry and X-ray diffraction were used to identify the compositions and phases in the microstructure. Dependence of eutectic spacings (λ) on the growth rate (V), temperature gradient (G) and cooling rate ( ) were determined using linear regression analysis. From the experimental results, it can be concluded that the values of λ decrease with the increasing the values of V, G and . The value of λ2V was determined using the measured values of λ and V. The results obtained in the present work have been compared with previous results obtained for binary or ternary alloys.
2
The Dependence of Lamellar Spacings and Microhardness on the Growth Rate in the Directionally Solidified Bi-43 wt.% Sn Alloy at a Constant Temperature Gradient

E. Çadlrll,H. Kaya,N. Marasll 대한금속·재료학회 2009 METALS AND MATERIALS International Vol.15 No.5
Bi-43 wt.% Sn eutectic samples were directionally solidified upward with five different growth rates (V = 8.3- 164.8 μm/s) at a constant temperature gradient (G = 3.55 K/mm) in a Bridgman type directional solidification furnace. The lamellar spacings (λ) and microhardness values (HV) were measured from the quenched samples; the directionally solidified Bi-43 wt.% Sn eutectic alloy and the minimum undercoolings (ΔT) were determined from the Jackson–Hunt eutectic theory. The dependency of lamellar spacings (λ), microhardness (HV) and undercooling (ΔT) on the growth rate (V) were analyzed. According to these results, it has been found that the value of λ decreases with the increasing value of V and that the values of HV and ΔT increase for a constant G. The values of λ 2 V, λΔT and ΔT V -0.5 were determined by using the values of λ, ΔT and V. The results obtained in the present work have been compared with those predicted by the Jackson–Hunt eutectic theory and with similar experimental results. Bi-43 wt.% Sn eutectic samples were directionally solidified upward with five different growth rates (V = 8.3- 164.8 μm/s) at a constant temperature gradient (G = 3.55 K/mm) in a Bridgman type directional solidification furnace. The lamellar spacings (λ) and microhardness values (HV) were measured from the quenched samples; the directionally solidified Bi-43 wt.% Sn eutectic alloy and the minimum undercoolings (ΔT) were determined from the Jackson–Hunt eutectic theory. The dependency of lamellar spacings (λ), microhardness (HV) and undercooling (ΔT) on the growth rate (V) were analyzed. According to these results, it has been found that the value of λ decreases with the increasing value of V and that the values of HV and ΔT increase for a constant G. The values of λ 2 V, λΔT and ΔT V -0.5 were determined by using the values of λ, ΔT and V. The results obtained in the present work have been compared with those predicted by the Jackson–Hunt eutectic theory and with similar experimental results.
3
Influence of Growth Rate on Microstructure, Microhardness, and Electrical Resistivity of Directionally Solidified Al-7 wt% Ni Hypo-Eutectic Alloy

H. Kaya,U. Böyük,E. Çadlrll,N. Marasll 대한금속·재료학회 2013 METALS AND MATERIALS International Vol.19 No.1
Al-7 wt% Ni alloy was directionally solidified upwards with different growth rates, V (8.3-489.5 μm/s) at constant temperature gradient, G (4.2 K/mm) using a Bridgman-type growth apparatus. The dependence of the dendritic microstructures such as primary dendrite arm spacing (λ1) and secondary dendrite arm spacing (λ2) on the growth rate were determined using a linear regression analysis. The present experimental results were also compared with similar previous experimental results. Measurements of microhardness (HV) and electrical resistivity (ρ) of the directionally solidified samples were carried out. The dependence of the microhardness and electrical resistivity on the growth rate (V) was also analyzed. According to these results, it has been found that, for increasing values of V, the values of HV and ρ increase. However, the values of HV and ρ decrease with increasing values of λ1 and λ2.
4
Determination of Interfacial Energies for Solid Al Solution in Equilibrium with Al-Cu-Ag Liquid

K. Ke lio lu,Y. Ocak,S. Aksöz,N. Mara ll,E. Çadlrll,H. Kaya 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.1
The equilibrated grain boundary groove shapes of a solid Al solution in equilibrium with Al-Cu-Ag liquid were observed from a quenched sample using a radial heat flow apparatus. The Gibbs-Thomson coefficient,solid-liquid interfacial energy, and grain boundary energy of the solid Al solution were determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase for Al-16.42 at.% Ag-4.97at.% Cu and Al-16.57 at.% Ag-11.87 at.% Cu alloys and the thermal conductivity ratio of the liquid phase to the solid phase for Al-16.57 at.% Ag-11.87 at.% Cu alloy at the melting temperature were also measured with a radial heat flow apparatus and a Bridgman-type growth apparatus, respectively.

상세검색

RISS 보유자료

상세검색

해외전자자료

연관 검색어 추천