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A study of microstructure and solidification behaviour of Zn-Cu alloy
(REDAKCIA KOVOVE MATERIALY, 2010) Boyuk, U.; Engin, S.; Kaya, H.; Cadirli, E.; Marasli, N.; Keslioglu, K.
Zn-1.5wt.%Cu peritectic alloy was prepared in a graphite crucible under a vacuum atmosphere. Unidirectional solidification of Zn-1.5wt.%Cu peritectic alloy was carried out with the Bridgman method by using metals of 99.99 % purity under the argon atmosphere and two different conditions; with a temperature gradient (G) range of 1.99-7.81 K mm(-1) at constant growth rate (V) and a growth rate range of 8.41-661.11 mu m s(-1) at a constant temperature gradient. The microstructures of the directionally solidified Zn-1.5wt.%Cu peritectic samples were observed to be cellular. From both transverse and longitudinal sections of the samples, cellular spacing (lambda), and cell tip radius (R) were measured and expressed as functions of solidification processing parameters (G and V) using a linear regression analysis. The experimental results were also compared with values calculated according to the current theoretical and numerical models, and similar previous experimental results.
Dependence of Electrical Resistivity on Temperature and Sn Content in Pb-Sn Solders
(SPRINGER, 2011) Cadirli, E.; Boyuk, U.; Kaya, H.; Marasli, N.; Aksoz, S.; Ocak, Y.
Pb(100-x)-Sn-x solders (x = 5 wt.%, 10 wt.%, 20 wt.%, 35 wt.%, 50 wt.%, 60 wt.%, 61.9 wt.%, and 95 wt.%) were directionally solidified upward with a constant growth rate (V = 37.4 mu m/s) in a temperature gradient (G = 4.8 K/mm) in a Bridgman-type growth apparatus. The variations of electrical resistivity (rho) with temperature in the range of 323 K to 423 K for the directionally solidified Pb-Sn solders were measured. The present measurements indicate that the electrical resistivity of the directionally solidified Pb-Sn solders increases with increasing temperature, whereas the resistivity of the Pb-Sn solders decreases with increasing Sn content. The dependency of the Lorenz number (L) on temperature and Sn content for the Pb-Sn solders was also investigated based on the Wiedemann-Franz law by using the measured values of the thermal (K) and electrical (sigma) conductivity for the same alloys.
Dependency of Microstructural Parameters and Microindentation Hardness on the Temperature Gradient in the In-Bi-Sn Ternary Alloy with a Low Melting Point
(KOREAN INST METALS MATERIALS, 2008) Kaya, H.; Boyuk, U.; Cadirli, E.; Ocak, Y.; Akbulut, S.; Keslioglu, K.; Marasli, N.
The ternary alloy In-21.5 at.% Bi-17.8 at.% Sn, which has a melting point of 60 degrees C, was directionally solidified upward with a constant growth rate (V = 3.2 mu m/s) and different temperature gradients (G = 0.91 K/mm to 2.85 K/mm) by using a Bridgman-type directional solidification furnace. The lamellar spacings (lambda) and microhardness (H(v)) were measured from both the transverse and longitudinal sections of the samples. The dependence of the lamellar spacings (lambda) and microhardness (H(v)) on the temperature gradients (G) were determined by means of linear regression analysis. According to these results, the value of lambda decreases as the value of G increases and the value of Hv increases for a constant V. The results obtained in this work are compared with previous similar experimental results obtained for binary or ternary alloys.
Dependency of the thermal and electrical conductivity on the temperature and composition of Cu in the Al based Al-Cu alloys
(ELSEVIER SCIENCE INC, 2010) Aksoz, S.; Ocak, Y.; Marasli, N.; Cadirli, E.; Kaya, H.; Boyuk, U.
The variations of thermal conductivity with temperature for Al-[x] wt.% Cu, x = 3, 6, 15 and 24 alloys were measured by using a radial heat flow apparatus. The variations of electrical conductivity of solid phases versus temperature for the same alloys were determined from the Wiedemann-Franz and Smith-Palmer equations by using the measured values of thermal conductivity. From the graphs of thermal and electrical conductivity versus temperature, the thermal conductivity of the solid phases at their melting temperatures, and the thermal temperature and the electrical coefficients for the same alloys were obtained. Dependency of the thermal and electrical conductivity on the composition of Cu in the Al based Al-Cu alloys were also investigated. According to present experimental results, the thermal and electrical conductivity of Al-[x] wt.% Cu, x = 3, 6, 15 and 24 alloys linearly decrease with increasing the temperature and composition of Cu. The enthalpy of fusion and the specific heat change during the transformation for the same alloys were determined from cooling trace during the transformation from eutectic liquid to eutectic solid by means of differential scanning calorimeter (DSC). (c) 2010 Elsevier Inc. All rights reserved.
Directional solidification of Al-Cu-Ag alloy
(SPRINGER HEIDELBERG, 2009) Boyuk, U.; Marasli, N.; Kaya, H.; Cadirli, E.; Keslioglu, K.
Al-Cu-Ag alloy was prepared in a graphite crucible under a vacuum atmosphere. The samples were directionally solidified upwards under an argon atmosphere with different temperature gradients (G=3.99-8.79 K/mm), at a constant growth rate (V=8.30 mu m/s), and with different growth rates (V=1.83-498.25 mu m/s), at a constant gradient (G=8.79 K/mm) by using the Bridgman type directional solidification apparatus. The microstructure of Al-12.80-at.%-Cu-18.10-at.%-Ag alloy seems to be two fibrous and one lamellar structure. The interlamellar spacings (lambda) were measured from transverse sections of the samples. The dependence of interlamellar spacings (lambda) on the temperature gradient (G) and the growth rate (V) were determined by using linear regression analysis. According to these results it has been found that the value of lambda decreases with the increase of values of G and V. The values of lambda (2) V were also determined by using the measured values of lambda and V. The experimental results were compared with two-phase growth from binary and ternary eutectic liquid.
Effect of solidification parameters on the microstructure of directionally solidified Sn-Bi-Zn lead-free solder
(KOREAN INST METALS MATERIALS, 2012) Cadirli, E.; Boyuk, U.; Kaya, H.; Marasli, N.
Sn-Bi-Zn lead free solder alloy was directionally solidified upward at a constant temperature gradient (G=3.99 K/mm) with a wide range of growth rates (8.3-478.6 mu m/s) and at a constant growth rate (V=8.3 mu m/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 (lambda) on the growth rate (V), temperature gradient (G) and cooling rate (a(1a)) were determined using linear regression analysis. From the experimental results, it can be concluded that the values of lambda decrease with the increasing the values of V, G and a(1a). The value of lambda V-2 was determined using the measured values of lambda and V. The results obtained in the present work have been compared with previous results obtained for binary or ternary alloys.
Experimental investigation of the effect of solidification processing parameters on the rod spacings in the Sn-1.2 wt.% Cu alloy
(ELSEVIER SCIENCE SA, 2009) Cadirli, E.; Boyuk, U.; Engin, S.; Kaya, H.; Marasli, N.; Ulgen, A.
Sn-1.2 wt.% Cu alloy was prepared in a graphite crucible under the vacuum atmosphere. The samples were directionally solidified upwards under argon atmosphere with different temperature gradients (G = 2.69-8.88 K/mm) at a constant growth rate (V = 6.80 mu m/s) and with different growth rates (V = 2.78-136.36 mu m/s) at a constant temperature gradient (G = 2.69 K/mm) by using a Bridgman-type directional solidification apparatus. The microstructure of Sn-1.2 wt.% Cu alloy seems to be rod eutectic structure. The rod spacings (lambda) were measured from both transverse and longitudinal sections of the samples. The influence of the growth rate (V) and temperature gradient (G) on the rod spacings (lambda) and undercoolings (Delta T) was analysed. The values of lambda(2)V, lambda(2)G, Delta T lambda, Delta TV(-0.5) and Delta TG(0.5) were determined by using the Jackson-Hunt eutectic theory. The results obtained in the present work have been compared with the similar experimental results obtained in the previous works for binary alloys. (C) 2009 Elsevier B.V. All rights reserved.
Influence of growth rate on microstructure, microhardness, and electrical resistivity of directionally solidified Al-7 wt% Ni hypo-eutectic alloy
(KOREAN INST METALS MATERIALS, 2013) Kaya, H.; Boyuk, U.; Cadirli, E.; Marasli, N.
Al-7 wt% Ni alloy was directionally solidified upwards with different growth rates, V (8.3-489.5 mu m/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 (lambda (1)) and secondary dendrite arm spacing (lambda (2)) 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 (rho) 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 rho increase. However, the values of HV and rho decrease with increasing values of lambda (1) and lambda (2).
Investigation of directional solidified Al-Ti alloy
(ELSEVIER SCIENCE BV, 2009) Kaya, H.; Cadirli, E.; Boyuk, U.; Marasli, N.
Al-1 wt% Ti alloy was directionally solidified upwards under argon atmosphere under the two conditions; with different temperature gradients (G = 2.20-5.82 K/mm) at a constant growth rate (V = 8.30 mu m/s) and with different growth rates (V = 8.30-498.60 mu m/s) at a constant temperature gradient (G = 5.82 K/mm) in a Bridgman furnace. The dependence of characteristic microstructure parameters such as primary dendrite arm spacing (lambda(1)), secondary dendrite arm spacing (lambda(2)), dendrite tip radius (R) and mushy zone depth (d) on the velocity of crystal growth and the temperature gradient were determined by using a linear regression analysis. A detailed analysis of microstructure development with models of dendritic solidification and with previous similar experimental works on dendritic growth for binary alloys were also made. (C) 2009 Elsevier B.V. All rights reserved.
Investigation of microhardness and thermo-electrical properties in the Sn-Cu hypereutectic alloy
(SPRINGER, 2010) Cadirli, E.; Boyuk, U.; Engin, S.; Kaya, H.; Marasli, N.; Ari, M.
Sn-3 wt% Cu hypereutectic alloy was directionally solidified upward with different growth rates (2.24-133.33 mu m/s) at a constant temperature gradient (4.24 K/mm) and with different temperature gradients (4.24-8.09 K/mm) at a constant growth rate (7.64 mu m/s) in the Bridgman-type growth apparatus. The measurements of microhardness of directionally solidified samples were obtained by using a microhardness test device. The dependence of microhardness HV on the growth rate (V) and temperature gradient (G) were analyzed. According to these results, it has been found that with the increasing the values of V and G the value of HV increases. Variations of electrical resistivity (rho) and electrical conductivity (sigma) for casting samples with the temperature in the range of 300-500 K were also measured by using a standard dc four-point probe technique. The variation of Lorenz coefficient with the temperature for Sn-3 wt% Cu hypereutectic alloy was determined by using the measured values of electrical and thermal conductivities. The enthalpy of fusion for same alloy was determined by means of differential scanning calorimeter from heating trace during the transformation from eutectic liquid to eutectic solid.
Investigation of the effect of solidification processing parameters on microhardness and determination of thermo-physical properties in the Zn-Cu peritectic alloy
(ELSEVIER SCIENCE SA, 2010) Boyuk, U.; Kaya, H.; Cadirli, E.; Marasli, N.; Ulgen, A.
Zn-1.5wt.% Cu peritectic alloy was directionally solidified upward with different growth rates (8.41-661.11 mu m/s) at a constant temperature gradient (7.81 K/mm) and with different temperature gradients (1.99-7.81 K/mm) at a constant growth rate (16.44 mu m/s) using a Bridgman-type directional solidification apparatus. The measurements of microhardness of directionally solidified samples were made by using a microhardness test device. The dependence of microhardness (HV) on the growth rate (V) and temperature gradient (G) were analyzed. According to these results, it has been found that with the increasing the values of V and G the values of HV increase. Variation of electrical resistivity (rho) and electrical conductivity (sigma) with the temperature in the range of 300 similar to 670 K for casting samples were also measured by using a standard d.c. four-point probe technique. The variation of Lorenz coefficient with the temperature was determined by using the measured values of electrical conductivity and thermal conductivity. The enthalpy of fusion and specific heat for same alloy were determined by means of differential scanning calorimeter (DSC) from the heating curve during the transformation from peritectic solid to peritectic liquid. (C) 2009 Elsevier B.V. All rights reserved.
Investigation of the effect of solidification processing parameters on the rod spacings and variation of microhardness with the rod spacing in the Sn-Cu hypereutectic alloy
(SPRINGER, 2010) Cadirli, E.; Boyuk, U.; Engin, S.; Kaya, H.; Marasli, N.; Keslioglu, K.; Ulgen, A.
Sn-3 wt% Cu hypereutectic alloy was prepared in a graphite crucible under the vacuum atmosphere. The samples were directionally solidified upwards under argon atmosphere with different temperature gradients (G = 4.24-8.09 K/mm) at a constant growth rate (V = 7.64 mu m/s) and with different growth rates (V = 2.24-133.33 mu m/s) at a constant temperature gradient (G = 4.24 K/mm) by using a Bridgman type directional solidification apparatus. The microstructure of directional solidified Sn-3 wt% Cu alloy seems to be rod eutectic structure. The influence of the growth rate (V) and temperature gradient (G) on the rod spacing (lambda) and undercooling (Delta T) were analysed. The values of lambda(2)V, lambda(2)G, Delta T lambda, Delta TV(-0.5) and Delta TG(-0.5) were determined by using the Jackson-Hunt eutectic theory. The dependence of microhardness (HV) on the rod spacing (lambda) was analyzed. According to present results, it has been found that the value of HV increases with the increasing the value of lambda.
Measurements of Microhardness and Thermal and Electrical Properties of the Binary Zn-0.7wt.%Cu Hypoperitectic Alloy
(SPRINGER, 2010) Kaya, H.; Boyuk, U.; Engin, S.; Cadirli, E.; Marasli, N.
Zn-0.7wt.%Cu hypoperitectic alloys were directionally solidified upwards with different temperature gradients (3.85 K/mm to 9.95 K/mm) at a constant growth rate (0.042 mm/s), and with different growth rates (0.0083 mm/s to 0.436 mm/s) at a constant temperature gradient (3.85 K/mm), using a Bridgman-type growth apparatus. Measurements of microhardness of the directionally solidified samples were carried out. The dependence of micro- hardness (HV) on growth rate (V) and temperature gradient (G) was analyzed. According to these results, it has been found that, for increasing values of G and V, the value of HV increases. Variations of electrical resistivity (rho) and electrical conductivity (sigma) for cast samples with temperature from 300 K to 670 K were also measured by using a standard direct-current (DC) four-point probe technique. The variation of the Lorenz coefficient with temperature for the Zn-0.7wt.%Cu hypoperitectic alloy was determined using the measured values of electrical conductivity and thermal conductivity. The enthalpy of fusion for the same alloy was determined by means of differential scanning calorimetry (DSC) from the heating trace during the transformation from liquid to solid.
Measurements of the microhardness, electrical and thermal properties of the Al-Ni eutectic alloy
(ELSEVIER SCI LTD, 2012) Kaya, H.; Boyuk, U.; Cadirli, E.; Marasli, N.
Al-5.7 wt% Ni eutectic alloy was directionally solidified upward with different temperature gradients (0.83-4.02 K/mm) at a constant growth rate (0.008 mm/s) and with different growth rates (0.008-0.483 mm/s) at a constant temperature gradient (4.02 K/mm). Microhardness (HV) and electrical resistivity (rho) of directionally solidified samples were measured using microhardness test device and a standard d.c. four-point probe technique, respectively. Dependency of the microhardness and electrical resistivity on the solidification processing parameters (temperature gradient, G and growth rate, (V) were analyzed. According to these results, it has been found that the values of HV and rho increase with the increasing values of G and V. Variations of electrical resistivity and electrical conductivity (sigma) for casting Al-Ni eutectic alloy were also measured at the temperature in range 300-720 K. The enthalpy of fusion (Delta H) for the Al-Ni eutectic alloy was determined by differential scanning calorimeter (DSC) from heating trace during the transformation from solid to liquid. (C) 2011 Elsevier Ltd. All rights reserved.
The effect of growth rate on microstructure and microindentation hardness in the In-Bi-Sn ternary alloy at low melting point
(ELSEVIER SCIENCE SA, 2009) Cadirli, E.; Boyuk, U.; Kaya, H.; Marasli, N.; Keslioglu, K.; Akbulut, S.; Ocak, Y.
In-21.5 at.% Bi-17.8 at.% Sn ternary alloy which has 333 K melting point was directionally solidified upward with a constant temperature gradient (G = 0.91 K/mm) in a wide range of growth rates (3.2-157.1 mu m/s) with a Bridgman type directional solidification furnace. The lamellar spacings (lambda) and microhardness values (H-V) were measured from both transverse and longitudinal sections of the samples. The dependence of lamellar spacings (lambda) and microhardness (H-V) on the growth rate (V) was determined by using linear regression analysis. According to these results, it has been found that the value of lambda decreases with the increasing value of V and whereas, the value of H-V increases for a constant G. The values of lambda V-2 were determined by using the measured values of lambda and V. The results obtained in this work have been compared with the previous similar experimental results obtained for binary or ternary alloys. (C) 2008 Elsevier B.V. All rights reserved.
Unidirectional solidification of aluminium-nickel eutectic alloy
(REDAKCIA KOVOVE MATERIALY, 2010) Kaya, H.; Boyuk, U.; Cadirli, E.; Marasli, N.
Aluminium nickel of (99 99 %) high purity eutectic alloy was melted in a graphite crucible under vacuum atmosphere The eutectic alloy was directionally solidified upward with a constant growth rate V (8 32 mu m s(-1)) and different temperature gradients G (0 83-4 02 K mm(-1)) and also with a constant G (4 02K mm(-1)) and different V (8 32-483 25 mu m s(-1)) in the Bridgman type directional solidification furnace The eutectic spacings lambda have been measured from both transverse section (lambda(T)) and longitudinal section (lambda(L) lambda(m) and lambda(M)) of the specimens The undercooling values Delta T were obtained by using V and system parameters K(1) K(2) It was found that the values of lambda decreased while V and G were increasing The relationships between eutectic spacing lambda and solidification parameters G and V were obtained by linear regression analysis The dependence of eutectic spacings lambda (lambda(T) lambda(L) lambda(m) and lambda(M)) on undercooling (Delta T) were also analysed lambda(2) V Delta T lambda Delta TV(-0 5) and lambda(2)G values were determined by using lambda Delta T V and G values The results obtained in this work were compared with the Jackson Hunt eutectic theory and similar experimental works
Variation of microindentation hardness with solidification and microstructure parameters in the Al based alloys
(ELSEVIER SCIENCE BV, 2008) Kaya, H.; Cadirli, E.; Boyuk, U.; Marasli, N.
The Al based alloys (Al-3 wt%Si, Al-3 wt%Cu and Al-1 wt%Ti) were prepared using metals of 99.99% high purity in the vacuum atmosphere. These alloys were directionally solidified upward with a constant growth rate (V = 0.008 mm/s) at the different temperature gradients (G = 1.1-6.8 K/mm) and also with a constant temperature gradient (G) in a wide range of growth rates (0.008-0.499 mm/s) with a Bridgman type directional solidi. cation furnace. The microstructure parameters (primary dendrite arm spacing, gimel(1), secondary dendrite arm spacing, gimel(2), dendrite tip radius, R, andmushy zone depth, d, were measured from both transverse and longitudinal section of the specimens as a function of G and V. The dependence of microhardness (H(V)) on the solidi. cation process parameters (V and G) and the microstructure parameters were determined by using linear regression analysis in the Al based alloys. The results obtained in this work have been compared with the previous similar experimental results obtained for binary or ternary alloys. (C) 2008 Elsevier B.V. All rights reserved.
Variations of microhardness with solidification parameters and electrical resistivity with temperature for Al-Cu-Ag eutectic alloy
(ELSEVIER SCIENCE BV, 2012) Boyuk, U.; Marasli, N.; Cadirli, E.; Kaya, H.; Keslioglu, K.
Al-Cu-Ag eutectic alloy was directionally solidified upwards with different growth rates (1.83-498.25 mu m/s) at a constant temperature gradient (8.79 K/mm) and with different temperature gradients (3.99-8.79 K/mm) at a constant growth rate (8.30 mu m/s) by using a Bridgman type directional solidification apparatus. The dependence of microhardness (HV) on the growth rate (V), temperature gradient (G) and microstructure parameter (lambda) were found to be HV = k(1) V(0.10), HV = k(2) G(0.13) and HV = k(3) lambda(-0.22), respectively. The electrical resistivity of the Al-Cu-Ag eutectic cast alloy increases linearly with the temperature in the range of 300-780 K. The enthalpy of fusion and specific heat change during melting for same alloy were also determined to be 223.8 J/g, and 0.433 J/g K, respectively by a differential scanning calorimeter from heating curve during the transformation from eutectic solid to eutectic liquid. (C) 2011 Elsevier B. V. All rights reserved.
Variations of microhardness with the solidification processing parameters and thermo-electrical properties with the temperature in the Sn-Cu alloy
(REDAKCIA KOVOVE MATERIALY, 2009) Cadirli, E.; Boyuk, U.; Engin, S.; Kaya, H.; Marasli, N.
Sn-1.2wt.%Cu eutectic alloy was directionally solidified upward with different growth rates (2-78-136.36 mu m s(-1)) at a constant temperature gradient (2.69 K mm(-1)) and with different temperature gradients (2.69-8.88 K mm(-1)) at a constant growth rate (6.80 mu m s(-1)) in the Bridgman-type growth apparatus. The measurements of microhardness of directionally solidified samples were obtained by using a microhardness test device. The dependence of microhardness HV on the growth rate (V) and temperature gradient (G) were analysed. According to these results, it has been found that with the increasing values of V and G, the values of HV increase. Variations of electrical resistivity (p) and electrical conductivity (a) for Sn-1.2wt.%Cu cast alloy with the temperature in the range of 300-500 K were also measured by using a standard d.c. four-point probe technique. The variation of Lorenz coefficient with the temperature for Sn-1.2wt.%Cu eutectic alloy was determined by using the measured values of electrical conductivity and thermal conductivity. The enthalpy of fusion for the same alloy was determined by means of differential scanning calorimeter (DSC) from heating trace during the transformation from eutectic liquid to eutectic solid.

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