Study of Artificial Aging Temperature Effect on Morphology of Structural Parameters in Aluminium Cast Alloy

2017 ◽  
Vol 891 ◽  
pp. 354-359
Author(s):  
Lenka Kuchariková ◽  
Eva Tillová ◽  
Mária Chalupová ◽  
Juraj Belan ◽  
Ivana Švecová ◽  
...  
Keyword(s):  
Artificial Aging ◽  
Cast Alloy ◽  
Structural Parameters ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Holding Time ◽  
Different Temperatures ◽  
Alloy Microstructure

The contribution describes changes in morphology of structural parameters in recycled (secondary) AlSi9Cu3 cast alloy microstructure. These changes depended on different temperatures of artificial aging. The T6 heat treatment, which was used for affecting the structural parameters morphology, consisted of solution treatment at temperature 515 °C with holding time 4 hours, water quenching at 40°C and artificial aging at different temperatures 130 °C, 150 °C, 170 °C, 190 °C and 210 °C with different holding time 2, 4, 8, 16 and 32 hours. The morphology of structural parameters was observed using combination of different analytical techniques (light microscopy upon black-white and colour etching, scanning electron microscopy - SEM upon deep etching). The different temperatures of artificial aging led to changes in microstructure include the spheroidization and coarsening of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases, the dissolution of precipitates and the precipitation of finer hardening phase (Al2Cu).

Identification and Analysis of Intermetallic Phases in Age-Hardened Recycled AISi9Cu3 Cast Alloy

2012 ◽  
Vol 59 (4) ◽  
pp. 385-396 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Tensile Strength ◽  
Automotive Industry ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Holding Time ◽  
Age Hardening ◽  
Image Analyzer

PurposeThe influence of age-hardening solution treatment at temperature 515_C with holding time 4 hours, water quenching at 40_C and artificial aging by different temperature 130_C, 150_C, 170_C and 210_C with different holding time 2, 4, 8, 16 and 32 hours on changes in morphology of Fe-rich Al15(FeMn)3Si2 and Cu-rich (Al2Cu, Al-Al2Cu-Si) intermetallic phases in recycled AlSi9Cu3 cast alloy. Material/Methods: Recycled (secondary) AlSi9Cu3 cast alloy is used especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Microstructure was observed using a combination of different analytical techniques (scanning electron microscopy upon standard and deep etching and energy dispersive X-ray analysis - EDX) which have been used for the identification of the various phases. Quantitative study of changes in morphology of phases was carried out using Image Analyzer software NIS-Elements. The mechanical properties (Brinell hardness and tensile strength) were measured in line with STN EN ISO. Results/Conclusion: Age-hardening led to changes in microstructure include the spheroidization of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases and Al-Al2Cu-Si phases were fragmented, dissolved and redistributed within _-matrix. These changes led to increase in the hardness and tensile strength in the alloy.

Microstructural and Vickers Microhardness Evolution of Heat Treated Secondary Aluminium Cast Alloy

2013 ◽  
Vol 586 ◽  
pp. 137-140 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Artificial Aging ◽  
Vickers Microhardness ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Holding Time ◽  
Age Hardening ◽  
Structural Components ◽  
Heat Treated

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.

The Changes of Fatigue Properties in Aluminium Cast Alloy during Solution Treatment

2013 ◽  
Vol 592-593 ◽  
pp. 433-436 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Fatigue Test ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Testing Machine ◽  
Solution Treatment ◽  
Natural Aging ◽  
Load Ratio ◽  
Fatigue Properties ◽  
Area Reduction ◽  
Different Temperatures

This paper describes the effect of solution treatment on the fatigue properties of AlSi9Cu3 cast alloy. The heat treatment consisted of a solution treatment at two different temperatures 515°C and 525°C, a holding time of 4 hours; water quenching at 40°C and natural aging at room temperature for 24 hours. Thus prepared samples were subjected to fatigue test with a rotating bending loading (testing machine ROTOFLEX operating at 30 Hz, load ratio R = -1). The fatigue fracture surfaces were observed using a scanning electron microscope (SEM) after the fatigue test. The results showed that the existence of casting defects (8.4 % of micro-shrinkage) has considerable influence on fatigue properties and can be considered as fatigue crack initiators in what leads to final fatigue damage. Apart from cast defects, the morphology of eutectic silicon and intermetallic phases (Fe- and Cu-rich phases) are also important factors which have an influence on the fatigue properties of Al-Si cast components. The solution treatment used (at 525°C/4hours) has increased fatigue properties (the fatigue lifetime increased from 49 to 76 MPa), thanks to Si particles, morphology changes, and cast defects area reduction as well as reduction Fe-rich phases.

Optimization of Eutectic Si Particles Morphology in Secondary Al-Si Cast Alloys after Different Heat Treatment

2014 ◽  
Vol 1025-1026 ◽  
pp. 349-354 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Heat Treatment ◽  
Cast Alloy ◽  
Structural Parameters ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Structure Parameters ◽  
Eutectic Si ◽  
Cast Alloys ◽  
Morphology Changes ◽  
Scanning Electron

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.

Effect of heat treatment on corrosion and ultrasonic cavitation erosion resistance of AlSi10MnMg alloy

2020 ◽  
Vol 62 (9) ◽  
pp. 921-926
Author(s):  
Ion Dragoş Uţu ◽  
I. Mitelea ◽  
I. Bordeașu ◽  
F. Franţ
Keyword(s):  
Solid Solution ◽  
Solution Structure ◽  
Artificial Aging ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Mechanical Tests ◽  
Ultrasonic Cavitation ◽  
Cavitation Erosion Resistance

Abstract The investigated alloy is modified by casting with Sr in order to finish the eutectic silicon from microstructure and furthermore subjected to solution treatment followed by natural or artificial aging to improve the usage properties. Metallographic investigations and X-ray diffraction analyses showed that the heat treated microstructure consists of α- solid solution crystals with aluminum base, α + Si eutectic and intermetallic Al-Mn-Si phases. Mechanical tests and ultrasonic cavitation measurements showed that the highest mechanical characteristics and cavitation erosion resistance properties are obtained by applying the solution treatment followed by artificial aging. In contrast, electrochemical tests carried out in a saline concentration of 3.5 % NaCl in order to determine the corrosion rate, indicated that although there are no significant differences between the three structural states, a slight improvement was found in the corrosion behavior after applying the solution treatment followed by both natural and artificial aging. The phenomenon was demonstrated by shifting the values of corrosion currents from 2.66 μm/cm2 for the as-cast state, to 1.81 μm/cm2 and 1.52 μm/cm2, respectively, for the aged states. Finally, analysis of the cavitation eroded surface highlights the presence in the areas with α-solid solution structure of some flat-bottomed striped pinches, characteristic of fatigue fracture and of microcraters in the micro-zones where the fragile intermetallic phases were dislocated.

Transformation of Fe-rich intermetallic phases and eutectic Si morphology in Al–Si–Cu–Fe cast alloy with solution treatment

2019 ◽  
Vol 6 (6) ◽  
pp. 066515
Author(s):  
Bo Jiang ◽  
Ze-Sheng Ji ◽  
Hong-Yu Xu ◽  
Mao-Liang Hu ◽  
Yong-Bing Zhang ◽  
...  
Keyword(s):  
Cast Alloy ◽  
Solution Treatment ◽  
Intermetallic Phases ◽  
Eutectic Si

scholarly journals Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys

2017 ◽  
Vol 62 (1) ◽  
pp. 397-403 ◽  
Author(s):  
L. Kuchariková ◽  
E. Tillová ◽  
M. Matvija ◽  
J. Belan ◽  
M. Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Thin Foils ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Cast Alloys

AbstractThe formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.

Effect of Heat Treatment on the Microstructure of Gravity Cast and Squeeze Cast Al-Si-Mg Alloy

2015 ◽  
Vol 830-831 ◽  
pp. 164-167
Author(s):  
Arjun Bala Krishnan ◽  
Kavin Selvaraj ◽  
Akhil Madhusoodhanan Geethakumari ◽  
Ravi Manickam
Keyword(s):  
Heat Treatment ◽  
Squeeze Casting ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
A356 Alloy ◽  
Sand Cast ◽  
Squeeze Cast ◽  
Cast Alloys ◽  
Gravity Cast

The present work deals with the effect of solutionising heat treatment on the features of Al-7Si-0.3Mg (A356) alloy in terms of microstructural modifications and hardness. The microstructure of sand cast and gravity cast alloys are coarse which results in lower strength compared to the alloys cast using modern casting techniques such as squeeze casting which is used for the fabrication of near-net-shaped castings. The influence of enhanced cooling rate on the hardness and microstructure of the squeeze casting technique has been exploited in the present study. In order to optimise the heat treatment process, the microstructure of the gravity and squeeze cast alloys were compared after solution treatment. The quantitative analysis of the microstructure was carried out using an image analyser attached to the optical microscope. The aspect ratio, particle count and circularity of eutectic silicon and SDAS are measured. The squeeze cast alloy is found to have finer microstructure with enhanced properties compared to the gravity cast alloy.

scholarly journals Investigation of the Effect of Heat Treatment on the Microstructures and Mechanical Properties of Al-13Si-5Cu-2Ni Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 688
Author(s):  
Zhi-Fa Wang ◽  
Tian-Jing Miao ◽  
Shu-Qing Kou ◽  
Shuang Zhang ◽  
Feng Qiu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Solution Treatment Temperature ◽  
Solid Solution Treatment ◽  
Microstructures And Mechanical Properties

An experimental investigation was carried out to study the effects of solid solution treatment and aging treatment on the microstructures and mechanical properties of an Al-13Si-5Cu-2Ni alloy. The results show that the size of eutectic silicon decreased with solid solution treatment temperature increasing until 510 °C. Subsequently, the eutectic silicon size continued to increase as the temperature increased to 520 °C. Initially, the acicular eutectic silicon of the as-cast alloy was 10.1 μm in size. After the solid solution treatment at 510 °C, the eutectic silicon size was reduced to 6.5 μm. The θ′ phase is the main strengthening phase in the alloy, therefore, the effect of aging treatment on θ′ phases was explored. As the aging time increased, the diameter, length, and fraction volume of the θ′ phases were found to increase. The main reason for the improved performance of this alloy following heat treatment is the passivation spheroidization of the silicon phase and Orowan strengthening due to the θ′ phases. The optimal tensile strength of an Al-13Si-5Cu-2Ni alloy was obtained after solid solution treatment at 510 °C for 8 h followed by an aging treatment at 165 °C for 8 h. Therefore, this work has great significance for promoting the application of Al alloys at high temperatures.

Effect of Pouring Temperature and Melt Treatment on Microstructure of Lost Foam Casting of AL-Si LM6 Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 295-300 ◽  
Author(s):  
Majid Karimian ◽  
Ali Ourdjini ◽  
Mohd Hasbullah Idris ◽  
M. Bsher ◽  
A. Asmael
Keyword(s):  
Cast Alloy ◽  
Eutectic Silicon ◽  
Lost Foam Casting ◽  
Grain Refiner ◽  
Pouring Temperature ◽  
Casting Quality ◽  
Melt Treatment ◽  
Different Temperatures ◽  
Lost Foam ◽  
Porosity Percentage

This paper presents the experimental investigation conducted on Al-Si cast alloy (LM6) cast using lost foam process. The main objective of the research is to investigate the effect of pouring temperature, section thickness and melt treatment on the microstructure of the lost foam casting of Al-Si alloy. Step pattern with five different sections was prepared from 20 kg/m³ density foam and poured at five different temperatures; 700, 720, 740, 760, and 780 with and without the addition of AlTiB as grain refiner. Analysis on microstructure, eutectic silicon spacing and porosity percentage were conducted to determine the effect of both parameters. The results show that pouring temperature has significant influence on the quality as well as microstructure of the lost foam casting of LM6 Al-Si alloy. Lower pouring temperature was found to produce finer microstructure casting. However, the addition of AlTiB as grain refiner did not affect the produced castings significantly whether in terms casting quality or microstructure.

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