EFFECT OF CU CONTENT AND GROWTH VELOCITY ON THE MICROSTRUCTURE PROPERTIES OF THE DIRECTIONALLY SOLIDIFIED AL-MN-CU TERNARY ALLOYS

2021 ◽  
Vol 5 (20) ◽  
pp. 756-764
Author(s):  
Uğur BÜYÜK ◽  
Emin ÇADIRLI ◽  
Hasan KAYA ◽  
M. İzzettin YILMAZER
Keyword(s):  
Growth Velocity ◽  
Primary Dendrite ◽  
Ternary Alloys ◽  
Directionally Solidified ◽  
Dendritic Spacing ◽  
Cu Content ◽  
Dendrite Arm Spacing ◽  
Vacuum Atmosphere ◽  
Primary Dendrite Arm Spacing ◽  
Solidification Furnace

In this work, influences of composition (Cu content) and growth velocity (V) on the microstructure (dendritic spacing) of Al–Mn–Cu ternary alloys have been investigated. Al–1.9Mn–xCu (x=0.5, 1.5 and 5 wt. %) alloys were prepared using metals of 99.90% high purity in the vacuum atmosphere. These alloys were directionally solidified upwards under various growth velocities (8.3–978 m/s) using a Bridgman-type directional solidification furnace at a constant temperature gradient (7.1 K/mm). Measurements of primary dendrite arm spacing () of the samples were carried out and then expressed as functions of growth velocity and Cu content. Especially, cell-dendritic transition was detected for low growth velocity (41.6 m/s) for alloys containing 0.5 and 1.5Cu. It has been found that the values of  decrease with increasing V and decreasing Cu content. Keywords: Aluminum alloys, Solidification, Cell-dendritic transition, Dendrite arm spacing

Relationship between Growth Rates and Dendritic Microstructure Parameters in Al-5wt. Zn Binary Alloy

2013 ◽  
Vol 765 ◽  
pp. 215-219 ◽  
Author(s):  
Emine Acer ◽  
Harun Erol ◽  
Mehmet Gündüz
Keyword(s):  
Growth Rates ◽  
Numerical Models ◽  
Primary Dendrite ◽  
Linear Regression Analysis ◽  
Experimental Results ◽  
Directionally Solidified ◽  
Dendritic Microstructure ◽  
Dendrite Arm Spacing ◽  
Primary Dendrite Arm Spacing ◽  
Microstructure Parameters

Al-5 wt.% Zn samples were prepared using high purity (99.99%) metals in graphite crucibles. The samples were directionally solidified upward with a constant temperature gradient (G= 5.5 Kmm-1) and different growth rates,V, (8.25-165 μm/s) in a Bridgman type directional solidification apparatus. The dendritic spacings (λ1: Primary dendrite arm spacing, and λ2: Secondary dendrite arm spacing) were measured from the longitudinal sections of the samples and λ1was also measured from the transverse sections. The measured spacings were expressed as functions of the growth rates by using a linear regression analysis. The effect ofVon λ1and λ2were investigated. The experimental results were compared with the results of the current theoretical and numerical models and similar previous experimental results.

INFLUENCE OF THE SOLIDIFICATION PARAMETERS ON DENDRITIC MICROSTRUCTURES IN UNSTEADY-STATE DIRECTIONALLY SOLIDIFIED OF LEAD–ANTIMONY ALLOY

2010 ◽  
Vol 17 (05n06) ◽  
pp. 477-486 ◽  
Author(s):  
M. ŞAHIN ◽  
E. ÇADIRLI ◽  
H. KAYA
Keyword(s):  
Growth Rate ◽  
Primary Dendrite ◽  
Linear Regression Analysis ◽  
Theoretical Models ◽  
Directionally Solidified ◽  
Constant Growth Rate ◽  
Dendrite Arm Spacing ◽  
Primary Dendrite Arm Spacing ◽  
Microstructure Parameters ◽  
Solidification Parameters

Pb-9.3wt.%Sb alloy was directionally solidified upwards under argon atmosphere under the two conditions; with different temperature gradients, (G = 0.93–3.67 K/mm) at a constant growth rate (V = 17.50 μm/s) and with different growth rates (V = 8.30–497.00 μm/s) at a constant (G = 3.67 K/mm) in a Bridgman furnace. The dependence of characteristic microstructure parameters such as primary dendrite arm spacing (λ1), secondary dendrite arm spacing (λ2) and dendrite tip radius (R) on the growth rate (V) and the temperature gradient (G) were determined by using a linear regression analysis. A detailed analysis of microstructure were also made and compared with the theoretical models and similar experimental works on dendritic solidification in the literature.

Correlation between Thermal Parameters, Primary Dendrite Arm Spacing and Microhardness on a Directionally Solidified Ternary Al-6wt%Cu-8wt%Si Alloy

2015 ◽  
Vol 365 ◽  
pp. 136-141
Author(s):  
O.L. Rocha ◽  
A.L. Moreira ◽  
T.A. Costa ◽  
J.M.D. Filho ◽  
S.L. Paula ◽  
...  
Keyword(s):  
Experimental Study ◽  
Primary Dendrite ◽  
Thermal Parameters ◽  
Heat Extraction ◽  
Directionally Solidified ◽  
Power Functions ◽  
Microstructural Parameters ◽  
Dendrite Arm Spacing ◽  
Primary Dendrite Arm Spacing ◽  
Analytical Power

The objective of this paper is to present an experimental study that aimed to establish correlations between primary dendrite spacing (λ1) and microhardness of a ternary Al-6wt%Cu-8wt%Si alloy solidified under transient heat extraction, using a horizontal unidirectional water-cooled solidification device. To examine the microstructural evolution, solidification thermal parameters (growth rate and cooling rate - VLand TR, respectively) were calculated through the application of an experimental method and were then correlated with λ1using analytical power functions laws. The correlation between microstructural parameters and the measured microhardness values are presented in the forms of power and Hall-Petch types of equations. The analysis of the microstructure of the investigated alloy indicated that the increasing of TRand VLreduced the primary dendrite arm spacing, increasing the microhardness.

SOLIDIFICATION CHARACTERISTICS AND MICROSTRUCTURAL EVOLUTION OF Zn-1.26wt.% Al ALLOY

2011 ◽  
Vol 18 (06) ◽  
pp. 281-288 ◽  
Author(s):  
MEVLÜT ŞAHİN ◽  
EMİN ÇADIRLI
Keyword(s):  
Primary Dendrite ◽  
Linear Regression Analysis ◽  
Al Alloy ◽  
Constant Growth Rate ◽  
Dendrite Arm Spacing ◽  
Wide Range ◽  
Primary Dendrite Arm Spacing ◽  
Microstructure Parameters ◽  
Solidification Furnace ◽  
Tip Radius

Zn–1.26 wt.% Al alloy was directionally solidified upward with a constant growth rate (V = 16.6 μm/s) in a wide range of temperature gradients (G = 1.94–5.15 K/mm) and with a constant temperature gradient (G = 5.15 K/mm) in a wide range of growth rates (V = 8.3–500 μm/s) with a Bridgman-type directional solidification furnace. Microstructure parameters, the primary dendrite arm spacing (λ1), secondary dendrite arm spacing (λ2) and dendrite tip radius (R), were measured and expressed as functions of G and V by using a linear regression analysis method. It was found that the values of λ1, λ2 and R decrease with increasing values of V and G. The experimental results were compared with the main predictive theoretical and experimental works for dendritic spacings.

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