Microstructure Analysis of AlSi10MgMn Aluminium Cast Alloy

2014 ◽  
Vol 782 ◽  
pp. 365-368
Author(s):  
Mária Chalupová ◽  
Eva Tillová ◽  
Mária Farkašová

The present study was performed on primary AlSi10MgMn cast alloy to analyze the morphology and composition of complex microstructure of the intermetallic phases. AlSi10MgMn cast alloy is a typical casting alloy used for parts with thin walls and complex geometry. It offers good strength, hardness and dynamic properties and is therefore also used for parts subject to high loading. In this study, several methods were used such as: optical light microscopy (LM) and scanning (SEM) electron microscopy in combination with EDX analysis using standard etched or deep etched sample to identify intermetallic. Alloy was analyzed in as-cast state (rapidly cooled right after casting) and after T6 heat treatment. T6 treatment (solution annealing, quenching and age hardening) improves mechanical properties. The results show that the microstructure of AlSi10MgMn alloy consisted of several phases: α-matrix, eutectic, Fe-rich intermetallic phases (Al15(FeMn)3Si2, Al5FeSi), Mg2Si, Al8FeMg3Si6 and of other phases in formation. Iron-rich intermetallic phases are well known to be strongly influential on mechanical properties in Al-Si alloys. The most common morphology was the long platelets of Al5FeSi phase. After heat treatment were observed spheroidisation of eutectic Si, dissolution and fragmentation of Fe-phases.

2013 ◽  
Vol 586 ◽  
pp. 137-140 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová

Secondary aluminium alloys are made out of aluminium scrap and aluminium-processable waste by recycling. These alloys contain different alloying elements such as Al, Cu, Fe, Si and Mg that form intermetallic phases in aluminium matrix and influence on the microstructure, basic mechanical properties and microhardness evolution in aluminium cast alloy. As experimental material was used secondary aluminium cast alloy AlSi9Cu3. Material was subjected to heat treatment (age-hardening) consisting of a solution treatment at temperature 515 °C with holding time 4 hours, than water quenching at 40 °C and artificial aging by different temperature 130 °C, 150 °C and 170 °C with different holding time (2, 4, 8, 16 and 32 hours). The age-hardening led to changes in the morphology of structural components, but also leads to precipitation of finer hardening phases in the material substructure. As optimal age-hardening mode for secondary aluminium cast alloy AlSi9Cu3 was determined mode consisting of solution treatment at temperature 515 °C with holding time 4 hours and artificial aging at temperature 170 °C with holding time 16 hours. After this heat treatment cast alloy shows the best changes in microstructure and mechanical properties. These changes are comparable with changes by primary AlSi9Cu3 cast alloy.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1100
Author(s):  
Yanfeng Wang ◽  
Qian Liu ◽  
Zheng Yang ◽  
Changming Qiu ◽  
Kuan Tan

The effects of adding different Ce contents (0–0.32 wt.%) on the microstructure, mechanical properties, and fracture morphology of industrial A357 cast alloy in as-cast and T6 heat treatment were studied. The main purpose of this study is to improve the microstructure stability and tensile properties of industrial A357 cast alloy. The microstructural analyses indicate that the addition of Ce causes refinement of the α-Al primary phase for the reason that the formation of intermetallic compounds containing (AlSiCeMg) elements enriches the front of the solid–liquid interface, which causes an increase in constitutional undercooling. Simultaneously, the addition of Ce also affected the characteristics of eutectic Si particles, which make its morphology change from acicular structures into fragmented and spheroidized. This is mainly due to the formation of Ce-rich precipitates during solidification, which increase the constitutional undercooling and suppress the nucleation of the eutectic Si particles, resulting in the change of eutectic Si characteristics. Moreover, the needle-like morphology of a Fe-containing intermetallic is transformed into α(AlSiFeCe) phase containing rare earth Ce when part of the Ce atoms entered β(Al5FeSi) phase compounds. The tensile properties of the modified alloys were improved in the as-cast and T6 heat treatment as a consequence of simultaneous refinement of both secondary dendrite arm spacing and grains and the improvement of eutectic Si particles and Fe-containing intermetallic morphology. The fracture surface of the modified alloy has more dimples than the unmodified alloy, which indicates that the main fracture pattern of the modified alloy is dimple fracture caused by the crack of eutectic Si particles. The optimal percentage of Ce in industrial A357 cast alloy was determined to be 0.16 wt.% according to the change of microstructures structure and mechanical properties. These experimental results provide a new basis for adding rare earth Ce to improve the performance of parts in the actual production of industrial A357 cast alloy.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Miloš Matvija ◽  
Martin Fujda ◽  
Ondrej Milkovič ◽  
Marek Vojtko ◽  
Róbert Kočiško ◽  
...  

The changes in the microstructure and improvement in the mechanical properties of as-cast AlSi7MgCu0.5 alloy induced by the heat treatment and technique of equal channel angular pressing (ECAP) were investigated. The heat treatment of as-cast alloy performed before the ECAP technique was required to increase the plasticity of the alloy. Therefore, the samples of analysed alloys were solution annealed at optimized temperature of 823 K for 4 hours to dissolve the particles of intermetallicπ(Al8FeMg3Si6) phase and to spheroidize the Si particles. Subsequently, water quenching and artificial ageing at optimized temperature of 573 K for 5 hours was used to obtain an overaged alloy state. The microstructure of alloy was consisted ofα(Al) solid solution, eutectic Si particles, and intermetallicβ(Mg2Si), Q-Al4Mg5Si4Cu,α-Al12(Fe,Mn)3Si, and/orα-Al15(Fe,Mn)3Si2phase particles. The crystal structure of present phases was confirmed by hard X-ray diffraction at Deutsches Elektronen-Synchrotron (DESY) in Hamburg and by the selected area electron diffraction (SAED) performed inside the transmission electron microscope (TEM). The heat-treated alloy was processed by ECAP at room temperature following route A. Repetitive ECAP of alloy homogenized the heterogeneous as-cast microstructure and formed the ultrafine subgrain microstructure with elongated subgrains of 0.2 µm in width and 0.65 µm in length and the high dislocation density. Microstructural changes in alloy induced by both heat treatment and ECAP led to the high strain hardening of the alloy that appeared in an improvement in strength, ductility, and microhardness of alloy in comparison with as-cast alloy state.


2014 ◽  
Vol 1025-1026 ◽  
pp. 349-354 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová

Secondary cast Al-Si alloys containing more of additions elements and forming various structural parameters (intermetallic phases). The optimization of structure parameters morphology is necessary because the mechanical properties depend on changes in morphology of eutectic Si and intermetallic phases in Al-Si cast alloy. This article describes changes of eutectic Si morphology after heat treatment T4 and T6. The morphology changes were observed using combination different analytical techniques - light microscopy (upon black-white etching) and scanning electron microscopy - SEM (upon deep etching). For the experiment was used recycled (secondary) aluminium cast alloy AlSi9Cu3.


2017 ◽  
Vol 891 ◽  
pp. 350-353
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Alan Vaško ◽  
...  

Present work is focused on study of the effect of Sr-modification (0 %; 0.03 % and 0.05 %) on the microstructure and mechanical properties of recycled AlSi8Cu2Mn cast alloy. For study and identification of intermetallic phases’ were utilized standard, colour and deep etching in order to reveal the three-dimensional morphology of the silicon particles and intermetallic phases. For element composition of the specimen was used X-ray analysis. Finally, the effect of modification on silicon morphology, mechanical properties (UTS, ductility, hardness and impact energy) was examined.The results show that the addition of Sr into AlSi8Cu2Mn cast alloy should act as a modifier, so it supposes to change the eutectic Si-morphology. However, its effect as a Si-modifier is not as significant as we have expected. Strontium refined and changed morphology of Si and thereby improves mechanical properties, first of all ductility and impact energy.


2016 ◽  
Vol 857 ◽  
pp. 246-250
Author(s):  
Chung Seok Kim ◽  
Sang Guy Park ◽  
Won Sik Kong

This paper investigated the effects of two-step solution heat treatment of aluminum alloy for lightweight automotive on mechanical properties. Solution heat treatments in this study are applied to improve of mechanical properties through a single-step and two-step solution heat treatment. The microstructure of AlSiCu casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 40 um. In addition to the Al matrix, a large amount of coarsen eutectic Si, Al2Cu intermetallic phases and Fe-rich phases are identified. After solution heat treatment, the mechanical properties of two-step solution heat treatment alloy show higher values than as-cast and a single-step solution specimens. Consequentially, the two-step solution heat treatment could be used in automotive parts to improve mechanical properties.


2015 ◽  
Vol 60 (4) ◽  
pp. 3035-3042
Author(s):  
Ł. Poloczek ◽  
B. Dybowski ◽  
K. Rodak ◽  
R. Jarosz ◽  
A. Kiełbus

Aluminium alloys are characterized by a low density, acceptable mechanical properties and good technological properties. This unique connection of features made aluminium alloys perfect structural material for the transportation industry. Also, due to their good electrical conductivity they also found application in energy production industry. High mechanical properties and electrical conductivity of the Al-Si alloys with Mg addition may be achieved by heat treatment. However, the highest mechanical properties are achieved in the early stages of age hardening - due to precipitation of coherent phases, while high electrical conductivity may be achieved only by prolonged aging, during precipitation of semi-coherent or fully noncoherent, coarse phases. Carefully heat treated AlSi7Mg alloy may exhibit both fairly high electrical conductivity and slightly increased mechanical properties. The following article present results of the research of influence of heat treatment on the properties and microstructure of sand cast AlSi7Mg alloy. Microstructure observations were performed using light microscopy, scanning electron and scanning-transmission electron microscopy. Hardness and electrical conductivity of the AlSi7Mg alloy were investigated both in as-cast condition and after heat treatment. Maximum hardness of the alloy is achieved after solutioning at 540°C for 8h, followed by 72h of aging at 150°C, while maximal electrical conductivity after solutioning at 540°C for 48h, followed by 96h of aging at 180°C. Increase of the electrical conductivity is attributed to increasing distance between Si crystals and precipitation of semi coherent phases.


Alloy Digest ◽  
1953 ◽  
Vol 2 (10) ◽  

Abstract CONDULOY is a low beryllium-copper alloy containing about 1.5% nickel. It responds to age-hardening heat treatment for improved mechanical properties. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on casting, heat treating, machining, and joining. Filing Code: Cu-11. Producer or source: Brush Beryllium Company.


Alloy Digest ◽  
1953 ◽  
Vol 2 (12) ◽  

Abstract ALUMINUM 62S is a magnesium silicide type of wrought aluminum alloy with high resistance to fresh and salt water corrosion. It responds to age hardening heat treatment for high mechanical properties. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-11. Producer or source: Aluminum Company of America.


Alloy Digest ◽  
1969 ◽  
Vol 18 (4) ◽  

Abstract ALUMINUM 6062 is a magnesium silicide type of wrought aluminum alloy having good mechanical properties combined with high resistance to fresh and salt water corrosion. It responds to age-hardening heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive, shear, and bearing strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-186. Producer or source: Aluminum Company of America.


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