Effect of Al10Sr and TiB on the Microstructure and Solidification Behavior of AlMg5Si2Mn Alloy

2021 ◽  
Vol 326 ◽  
pp. 111-124
Author(s):  
Przemysław Snopiński
Keyword(s):  
Crystallization Process ◽  
Intermetallic Phases ◽  
Phase Morphology ◽  
Cooling Curve ◽  
Solidification Behavior ◽  
Grain Refiner ◽  
First Derivative

In the first stage of the experiment, the effect of Al10Sr modification and Al5TiB grain refiner and interaction of both additions on the microstructure of AlMg5Si2Mn alloy and Mg2Si phase morphology was investigated. Then the influence of Al10Sr and Al5TiB addition on nucleation temperatures of various intermetallic phases formed in AlMg5Si2Mn alloy also have been interpreted by the formation of distinct peaks in the first derivative cooling curve and microstructural observations. It was found that modification has a meaningful influence on the microstructure of the investigated alloy as well as the crystallization process

Influence of a Novel Master Alloy Addition on the Grain Refinement of Al-Si Cast Alloys

2013 ◽  
Vol 765 ◽  
pp. 311-315 ◽  
Author(s):  
Leandro Bolzoni ◽  
Magdalena Nowak ◽  
N. Hari Babu
Keyword(s):  
Grain Refinement ◽  
Master Alloy ◽  
Intermetallic Phases ◽  
Al Alloys ◽  
Grain Structure ◽  
Grain Refiner ◽  
Casting Alloys ◽  
Alloy Addition ◽  
Cast Alloys ◽  
The Impact

The grain refinement practice using Ti based chemical additions is well established for wrought Al alloys, especially in the last few decades. In the case of Al-Si casting alloys the practice of adding grain refiners and the impact on castability is not well established in industries. The main reason is the chemical instability of conventionally known Ti based grain refiner which reacts with silicon forming intermetallic phases. Recently, researchers at Brunel University have identified a novel chemical composition that can refine the grain structure of Al-Si alloys in an effective way. Over the last year, this novel grain refiner in the form of master alloy was developed and tested in various Al-Si cast alloys that are commonly used in industry. Significant grain refinement is obtained when the master alloy is added to the liquid metal prior to casting. Moreover, the grain size of the Al-Si cast alloys is observed to be less sensitive to cooling rate when the master alloy is added. In this work, the influence of addition of the master alloy on microstructural evolution of various Al-Si alloys cast under various cooling rates is presented.

scholarly journals Role B4C Addition on Microstructure, Mechanical, and Wear Characteristics of Al-20%Mg2Si Hybrid Metal Matrix Composite

2021 ◽  
Vol 11 (7) ◽  
pp. 3047
Author(s):  
Hamidreza Ghandvar ◽  
Mostafa Abbas Jabbar ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů ◽  
Abdollah Bahador ◽  
...  
Keyword(s):  
Tribological Properties ◽  
Hybrid Composite ◽  
Cooling Curve ◽  
Dry Sliding Wear ◽  
Solidification Behavior ◽  
Mechanical And Tribological Properties ◽  
Primary Mg2si ◽  
B4c Particles ◽  
Mean Size ◽  
Hybrid Metal Matrix Composite

In the current study, the effect of different B4C additions (0, 2.5, 5, and 10 wt%) on the microstructural, solidification behavior, mechanical, and tribological properties of Al-20%Mg2Si composite were studied by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), Vickers hardness, tensile, and dry sliding wear tests. The cooling curve thermal analysis (CCTA) approach was utilized to monitor the influence of B4C particles on the solidification behavior of Al-20%Mg2Si composite. The results revealed that the addition of B4C particles up to 10 wt% reduced the nucleation temperature (TN) and growth temperature (TG) of the primary Mg2Si phase. Moreover, the proper amount of B4C added to Al-20%Mg2Si composite has a significant effect on the microstructural alteration, mechanical, and tribological properties of the composite. The mean size of primary Mg2Si in Al-Mg2Si composite was 47 μm, in which with the addition of 5 wt% B4C, the particle size decreased to 33 μm. The highest UTS (217 MPa) and El% (7%) was achieved in Al-20%Mg2Si-5%B4C hybrid composite. The cast Al-20%Mg2Si composite revealed the brittle mode of fracture with some cleavage characterization, in which with the addition of 5%B4C, the fracture mode altered to a more ductile fracture. The wear results revealed that the Al-20%Mg2Si-5%B4C hybrid composite has the highest wear resistance with the lowest wear rate (0.46 mm3/Km) and friction coefficient (µ = 0.52) under 20 N applied load compared to other fabricated composites with mild abrasion as the governed wear mechanism.

scholarly journals Crystallization Process and Microstructural Evolution of Melt Spun Al-RE-Ni-(Cu) Ribbons

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 443
Author(s):  
Francisco G. Cuevas ◽  
Sergio Lozano-Perez ◽  
Rosa María Aranda ◽  
Raquel Astacio
Keyword(s):  
Crystallization Process ◽  
Primary Crystallization ◽  
Amorphous Structure ◽  
Intermetallic Phases ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Melt Spun ◽  
The Stability

The crystallization process, both at the initial and subsequent stages, of amorphous Al88-RE4-Ni8 alloys (RE = Y, Sm and Ce) has been studied. Additionally, the consequences of adding 1 at.% Cu replacing Ni or Al were studied. The stability of the amorphous structure in melt spun ribbons was thermally studied by differential scanning calorimetry, with Ce alloys being the most stable. The effect of Cu to reduce the nanocrystal size during primary crystallization was analyzed by transmission electron microscopy. This latter technique and x-ray diffraction showed the formation of intermetallic phases at higher temperatures. A clear difference was observed for the Ce alloy, with a simpler sequence involving the presence of Al3Ni and Al11Ce3. However, for the Y and Sm alloys, a more complex evolution involving metastable ternary phases before Al19RE5Ni3 appears, takes place. The shape of the intermetallics changes from equiaxial in the Ce alloys to elongate for Y and Sm, with longer particles for Sm and, in general, when Cu is added to the alloy.

High Potency Late Inoculation of Grey Cast Iron

2007 ◽  
Vol 23 ◽  
pp. 303-306 ◽  
Author(s):  
Mihai Chisamera ◽  
Iulian Riposan ◽  
Stelian Stan ◽  
C.B. Albu ◽  
C. Brezeanu ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Cast Iron ◽  
Solidification Process ◽  
Solidification Behavior ◽  
High Potency ◽  
Complex Alloy ◽  
First Derivative ◽  
Negative Peak ◽  
Grey Cast ◽  
Eutectic Undercooling

Inoculation comparisons were made between Calcium-bearing FeSi75 and a new complex alloy tablet (CAT) inoculant to compare their effects on late inoculation. Thermal analysis was used to study the solidification behavior and how FeSi75 and the CAT inoculants affect graphite nucleation. Quick-cup addition rates for FeSi75 ranged from 0.1% to 0.3% while the CAT, was added in much smaller amounts, 0.01 to 0.03%. Thermal analysis of the base low sulphur iron (0.02 %S) was characterized by excessive eutectic undercooling. It was found that an addition of 0.03% of the CAT had inoculation efficiency comparable to 0.2% to 0.3% Ca-FeSi75 in reducing the level of undercooling, recalescence and the maximum recalescence rate. A greater negative peak of the first derivative at the end of solidification process, that would minimize micro-shrinkage tendencies, was also obtained.

Quantitative Investigation of Hot Tearing of Al-Cu Alloy (206) Cast in a Constrained Bar Permanent Mold

2009 ◽  
Vol 618-619 ◽  
pp. 57-62
Author(s):  
Shi Min Li ◽  
Diran Apelian ◽  
K. Sadayappan
Keyword(s):  
Thermal Deformation ◽  
Hot Tearing ◽  
Experimental Methodology ◽  
Cooling Curve ◽  
Permanent Mold ◽  
Quantitative Investigation ◽  
Load Curve ◽  
First Derivative ◽  
Cu Alloy ◽  
Casting Industry

The mechanisms of hot tearing are generally understood; inadequate feeding initiates the tear and further thermal deformation propagates the tear. However, a reliable experimental methodology/apparatus to quantitatively measure and characterize hot tearing is not available for the casting industry. In this study, a hot tearing apparatus with a load cell and LVDT developed at CANMET-MTL was used to measure the load and contraction in the mushy zone of an Al-Cu alloy. The onset of hot tearing can be determined from the load curve, its first derivative and cooling curve. The linear solidification contraction of the bar is measured. Alloy 206, which is an alloy that is quite prone to hot tearing was evaluated by the apparatus; results are given and discussed.

scholarly journals The Role of Grain Refiner in the Nucleation of AlFeSi Intermetallic Phases During Solidification of a 6xxx Aluminum Alloy

2019 ◽  
Vol 50 (11) ◽  
pp. 5242-5252 ◽  
Author(s):  
A. Lui ◽  
P. S. Grant ◽  
I. C. Stone ◽  
K. A. Q. O’Reilly
Keyword(s):  
Grain Refinement ◽  
Intermetallic Phase ◽  
Intermetallic Phases ◽  
Primary Phase ◽  
Al Alloy ◽  
Grain Refiner ◽  
Phase Selection ◽  
Type Size ◽  
6Xxx Series

Abstract Primary grain refinement using inoculant additions and intermetallic compound (IMC) phase selection are critical aspects in the solidification of commercial aluminum alloys, controlling the final mechanical properties in service. Although there have been studies which suggest there are explicit interactions between the two phenomena, they have yet to be fully elucidated. Here, through study of intermetallic phase particles extracted from an inoculated casting, key features relating to the nucleation of different intermetallic phases via eutectic reactions are recognized and explained. In particular, rake-like IMCs are identified as initiation points for the deleterious $$\beta $$ β -AlFeSi IMC phase in a model 6xxx series Al alloy. A mechanism is proposed for how $${\text{TiB}}_{2}$$ TiB 2 inoculant particles, which are commonly used for primary phase refinement, play a role in enhancing the nucleation of intermetallic phases during eutectic reactions at the liquid/$$\alpha $$ α -Al interface in the final stages of solidification. The implication of this mechanism is that, after the event of primary grain refinement, any unused $${\text{TiB}}_{2}$$ TiB 2 inoculant particles could be contributing to IMC formation thereby affecting the overall type, size, and distribution of intermetallic phases in the solidified alloy.

scholarly journals Effect of Transition Elements on the Thermal Stability of Glassy Alloys 82Al–16Fe–2TM (TM: Ti, Ni, Cu) Prepared by Mechanical Alloying

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3978
Author(s):  
Nguyen Thi Hoang Oanh ◽  
Do Nam Binh ◽  
Dung Dang Duc ◽  
Quyen Hoang Thi Ngoc ◽  
Nguyen Hoang Viet
Keyword(s):  
Thermal Stability ◽  
Crystallization Process ◽  
Amorphous Matrix ◽  
Intermetallic Phases ◽  
Transition Elements ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glassy Alloys ◽  
Thermal Stability Of

In the present study, the thermal stability and crystallization behavior of mechanical alloyed metallic glassy Al82Fe16Ti2, Al82Fe16Ni2, and Al82Fe16Cu2 were investigated. The microstructure of the milled powders was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The results showed remarkable distinction in thermal stability of the alloys by varying only two atomic percentages of transition elements. Among them, Al82Fe16Ti2 alloy shows the highest thermal stability compared to the others. In the crystallization process, exothermal peaks corresponding to precipitation of fcc-Al and intermetallic phases from amorphous matrix were observed.

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
Keyword(s):  
Curve Analysis ◽  
Cooling Curve ◽  
Freezing Range ◽  
Cooling Curves ◽  
First Derivative ◽  
Cu Alloys ◽  
Fraction Solid ◽  
Analysis Technique ◽  
Cooling Curve Analysis ◽  
Crack Susceptibility

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. 

scholarly journals Structure and Properties Investigation of MCMgAl12Zn1 Magnesium Alloy

2013 ◽  
Vol 13 (1) ◽  
pp. 9-14 ◽  
Author(s):  
L.A. Dobrzański ◽  
M. Król
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Cooling Rate ◽  
Crystallization Process ◽  
Solidus Temperature ◽  
The Novel ◽  
Structure And Properties ◽  
First Derivative ◽  
Cast Magnesium ◽  
Process Structure

Abstract This work presents an influence of cooling rate on crystallization process, structure and mechanical properties of MCMgAl12Zn1 cast magnesium alloy. The experiments were performed using the novel Universal Metallurgical Simulator and Analyzer Platform. The apparatus enabled recording the temperature during refrigerate magnesium alloy with three different cooling rates, i.e. 0.6, 1.2 and 2.4°C/s and calculate a first derivative. Based on first derivative results, nucleation temperature, beginning of nucleation of eutectic and solidus temperature were described. It was fund that the formation temperatures of various thermal parameters, mechanical properties (hardness and ultimate compressive strength) and grain size are shifting with an increasing cooling rate.

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