scholarly journals Impact of major alloying elements on the solodification parameters of cast hypoeutectic AlSi6Cu (1–4 wt.%) and AlSi8Cu(1−4 wt.%) alloys

2014 ◽  
Vol 20 (4) ◽  
pp. 235-246 ◽  
Author(s):  
Mile B. Djurdjević ◽  
Srećko Manasijević

The present work displays the potential of cooling curve analysis to characterize the solidification path of cast hypoeutectic series of Al-Si6-Cu(1−4 wt.%) and Al-Si8- Cu(1−4 wt.%) alloys. The aim of this work was to examine how variation in chemical composition of silicon and copper may affect characteristic solidification temperatures, fraction solid, and thermal freezing range of investigated alloys. Eight different Al−Si−Cu alloys (Al-Si6-Cu1, Al-Si6-Cu2, Al-Si6-Cu3, Al-Si6-Cu4, Al-Si8-Cu1, AlSi8-Cu2, Al-Si8-Cu3 and Al-Si8-Cu4) have been analyzed applying cooling curve analysis technique. Characteristic solidification temperatures have been determined using cooling curves or their corresponding first derivative curves along with ΔT curves. Fraction solid curves determined from recorded cooling curves have been used to calculate terminal freezing range and estimate crack susceptibility coefficient for each alloy. Theoretical mode for prediction of the cracking susceptibility coefficient developed by Clyne and Davies has been considered in this work. In addition, a novel mathematical model for prediction of crack susceptibility coefficient based on data collected from cooling curve analysis has been proposed. 

10.30544/81 ◽  
2015 ◽  
Vol 21 (3) ◽  
pp. 207-222 ◽  
Author(s):  
Mehdi Dehnavi ◽  
Mohsen Haddad-Sabzevar ◽  
Mohamad Hasan Avazkonnadeh-Gharavol

The Al-Cu alloys have been widely used in aerospace, automobile, and airplane applications. Generally Al–Ti and Al–Ti–B master alloys are added to the aluminium alloys for grain refinement. The cooling curve analysis (CCA) has been used extensively in metal casting industry to predict microstructure constituents, grain refinement and to calculate the latent heat of solidification. The aim of this study is to investigate the effect of cooling rate and grain refinement on the thermal and thermodynamic characteristics of Al-Cu alloys by cooling curve analysis. To do this, Al-Cu alloys containing 3.7, and 4.8 wt.% Cu were melted and solidified with 0.04, 0.19, 0.42, and 1.08 K/s cooling rates. The temperature of the samples was recorded using a K thermocouple and a data acquisition system connected to a PC. Some samples were Grain refined by Al-5Ti-1B to see the effect of grain refinement on the aforementioned properties. The results show that, in a well refined alloy, nucleation will occur in a shorter time, and a undercooling approximately decreases to zero. The other results show that, with considering the cooling rate being around 0.1 °C/s, the Newtonian method is efficient in calculating the latent heat of solidification.


2014 ◽  
Vol 20 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Mehdi Dehnavi ◽  
Hosein Vafaeenezhad ◽  
Mohsen Haddad Sabzevar

Depending on the casting conditions and alloy composition, microstructure and properties of the aluminium alloys will be different. There are many techniques available for investigating the solidification of metals and alloys. In recent years computer-aided cooling curve analysis (CA-CCA) has been used to determine thermophysical properties of alloys, latent heat and solid fraction. The aim of this study was to investigate the effect of cooling rate on the structural features of Al-4.8 wt.%Cu alloy by thermal analysis of cooling curves. To do this, Al-4.8 wt.%Cu alloy was melted and solidified applying 0.04, 0.42, and 1.08 °C/sec cooling rates. The temperature of the samples was recorded using a K thermocouple and a data acquisition system connected to a PC. It was found that the formation temperatures of various thermal parameters such as (liquidus, solidus and eutectic temperatures) are shifting by increasing of cooling rate from 0.04 °C/sec to 1.08 °C/sec. The structural results show that grain size and secondary dendrite arm spacing decreased by increasing of cooling rate. 


2019 ◽  
Vol 140 (4) ◽  
pp. 1825-1836 ◽  
Author(s):  
Carlos González-Rivera ◽  
Anthony Harrup ◽  
Carla Aguilar ◽  
Adrián M. Amaro-Villeda ◽  
Marco A. Ramírez-Argáez

JOM ◽  
2011 ◽  
Vol 63 (11) ◽  
pp. 51-57 ◽  
Author(s):  
Mile B. Djurdjevic ◽  
Zoran Odanovic ◽  
Nadezda Talijan

Author(s):  
Daniel Larouche

Thermal analysis is applied on aluminum alloys by researchers to investigate mainly phase transformations, while it is regularly used for quality control purposes in industry. Techniques like cooling curve analysis, differential thermal analysis, differential scanning calorimetry, and isothermal calorimetry are amongst those most frequently used by scientists and engineers. These techniques will be described, and a mathematical description of the results will be developed. State-of-the-art quantification methods applied on aluminum alloys will be presented and criticized based on specific examples taken from the literature.


Author(s):  
Bernardo Hernández-Morales

2010 ◽  
Vol 41 (9) ◽  
pp. 2216-2223 ◽  
Author(s):  
John W. Gibbs ◽  
Michael J. Kaufman ◽  
Robert E. Hackenberg ◽  
Patricio F. Mendez

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