The Failure Degradation of Recycled Aluminium Alloys with High Content of β-Al5FeSi Intermetallic Phases

2020 ◽  
Vol 403 ◽  
pp. 97-102
Author(s):  
Denisa Medvecká ◽  
Lenka Kuchariková ◽  
Milan Uhríčik
Keyword(s):  
Aluminium Alloys ◽  
Cast Alloy ◽  
Intermetallic Phases ◽  
X Ray ◽  
Fracture Surfaces ◽  
Phase Lead ◽  
Micro Cracks ◽  
Fe Content ◽  
Increased Risk ◽  
Cast Alloys

In this study, the effect of the β-Al5FeSi phases on fracture surfaces in secondary AlSi7Mg0.3 cast alloys with common and higher amount of iron was investigated. Iron addition caused the formation of different Fe-rich intermetallic phases in aluminium alloys. Components made of secondary aluminium alloys commonly have a higher amount of such phases. Sharp needles as β-Al5FeSi phase lead to initiate stress tension, thereby contributing to increased risk of micro-cracks formation on the fracture surfaces. To determine the effect of β-Al5FeSi to fracture surfaces of AlSi7Mg0.3 cast alloy, SEM microscopy with energy-dispersive X-ray spectroscopy (EDX) was used to study the amount of needles phases, their morphology and violation wave. It was found that increasing Fe content increased the size and the number of Al5FeSi phases. The fractographic analysis of fracture surfaces shows an increasing amount of cleavage fracture in materials with a higher amount of iron, too.

Optical and Scanning Electron Microscope Studies of Recycled (Secondary) Al-Si Cast Alloys

2013 ◽  
Vol 203-204 ◽  
pp. 266-271 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová ◽  
Jaroslaw Piątkowski
Keyword(s):  
Automotive Industry ◽  
Alloy Composition ◽  
Cast Alloy ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Energy Materials ◽  
X Ray ◽  
Cast Alloys ◽  
Second Phases ◽  
Scanning Electron

Production of primary Al- alloys belong to heavy source fouling of life environs. Care of environment in industry of aluminium connects with the decreasing consumptions resource as energy, materials, water and soil, with increase recycling and extension life of products. Recycled (secondary) aluminium alloys are made out of Al-scrap and workable Al-garbage by recycling. Applications of these alloys in recent years increase especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Controlling the microstructure of secondary aluminium cast alloy is very important, because these alloy containing more of additions elements, that forming various intermetallic phases in the structure. Improved mechanical properties of secondary alloys are strongly dependent upon the morphologies, type and distribution of the second phases, which are in turn a function of alloy composition and cooling rate. The presence of additional elements as Mg, Mn, Fe or Cu allows many complex intermetallic phases to form, which make characterization non-trivial. A combination of different analytical techniques (light microscopy, scanning electron microscopy (SEM) upon deep etching and energy dispersive X-ray analysis (EDX)) were therefore been used for the various phases identification.

scholarly journals Brazing of Titanium with Aluminium Alloys

2017 ◽  
Vol 62 (2) ◽  
pp. 763-770 ◽  
Author(s):  
A. Winiowski ◽  
D. Majewski
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Aluminium Alloys ◽  
Energy Dispersive Spectrometry ◽  
Intermetallic Phases ◽  
Shear Tests ◽  
X Ray ◽  
Diffusion Brazing ◽  
Brazed Joints ◽  
Scanning Electron

Abstract This study presents results of vacuum diffusion brazing of Grade 2 titanium with 6082 (AlMg1Si0.6Cu0.3) aluminium alloy using B-Ag72Cu-780 (Ag72Cu28) grade silver brazing metal as an interlayer. Brazed joints underwent shear tests, light-microscopy-based metallographic examinations and structural examinations using scanning electron microscopy (SEM) and X-ray energy dispersive spectrometry (EDS). The highest quality and shear strength of 20 MPa was characteristic of joints brazed at 530°C with a 30-minute hold. The structural examinations revealed that in diffusion zone near the boundary with titanium the braze contained solid solutions based on hard and brittle Ti-Al type intermetallic phases determining the strength of the joints.

The Effect of Lithium on the Microstructure and Morphology of Fe-Rich Intermetallic Compounds in 360 Cast Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 1782-1787
Author(s):  
N. Nasiri ◽  
M. Emamy ◽  
M. Bigdeli
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Intermetallic Compounds ◽  
Cast Alloy ◽  
Average Length ◽  
Intermetallic Phases ◽  
Maximum Length ◽  
Maximum Reduction ◽  
Fe Content

In this study, the effect of small additions of lithium on the microstructure and morphology of Fe-containing intermetallic compounds in A360 alloy has been investigated. Different Fe contents (1, 1.5 and 2%) were added into A360 alloy, and Li concentrations also varied from 0 to 0.5 wt. %. The image analysis results showed that, the maximum length of β-Al5FeSi plate in Li-modified specimens is changed significantly in comparison with non-modified ones. It is evident that the maximum reduction in the average length of Fe containing platelets occurs in specimens with 2% Fe. Also, the lowest changes in the length of intermetallic phases -as Fe content decreases- occur in the 0.5 wt% Li. At higher Li concentrations, the presence of Al-Li-Si intermetallics in the microstructure can provide undesirable condition. This intermetallic can be so damaging in mechanical properties especially in coarse shapes.

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.

Improvement of Microstructure and Mechanical Properties of Secondary AlSi8Cu2Mn Cast Alloy by Strontium

2017 ◽  
Vol 891 ◽  
pp. 350-353
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Alan Vaško ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Cast Alloy ◽  
Three Dimensional ◽  
Intermetallic Phases ◽  
Element Composition ◽  
X Ray ◽  
Sr Modification ◽  
Microstructure And Mechanical Properties ◽  
Eutectic Si

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.

scholarly journals The Effect of Iron Content on Microstructure and Porosity of Secondary AlSi7Mg0.3 Cast Alloy

2018 ◽  
Vol 47 (4) ◽  
pp. 283-289 ◽  
Author(s):  
Denisa Závodská ◽  
Eva Tillová ◽  
Ivana Švecová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Image Analysis ◽  
Iron Content ◽  
Cast Alloy ◽  
Intermetallic Phases ◽  
Shrinkage Porosity ◽  
High Porosity ◽  
Fe Content ◽  
Porosity Defects ◽  
Determine Effect

In the present study, microstructure and porosity of AlSi7Mg0.3 cast alloy including various amounts (0.123; 0.454 and 0.655 wt. %) of iron were investigated. The alloys were produced as secondary (scrap-based - recycled). Iron leads to the formation of complex intermetallic phases during solidification, and how these phases can adversely affect mechanical properties, especially ductility, and also lead to the formation of excessive shrinkage porosity defects in castings. In order to determine the effect of iron addition to AlSi7Mg0.3 alloy, optical and SEM microscopy with EDX were used for microstructural examinations. Image analysis was conducted in order to determine effect of the Fe content on phases and porosity. It was found that increasing Fe content from 0.123 to 0.655 wt. % has no effect on SDAS but the morphology of Al-Si eutectic became finer. From EDX examinations, different Fe-based intermetallic phases (β-Al5FeSi and α-Al15(FeMg)3Si2) were observed. It was also observed that as Fe content increased, α-Al15(FeMg)3Si2 phases was transformed into Al5FeSi and the size and the number of Al5FeSi phases increases. The image analysis results revealed that porosity values were by increasing Fe content increased too. We can to predict, that with the increasing amount of Fe decreasing the mechanical properties (first of all) ductility (through long β-Al5FeSi intermetallic and high porosity).

The Microstructure of Rapidly Solidified Al-Zn-Mg-Cu Alloys with Zr Addition

2010 ◽  
Vol 163 ◽  
pp. 42-45 ◽  
Author(s):  
Lidia Lityńska-Dobrzyńska ◽  
Patrick Ochin ◽  
Anna Góral ◽  
Marek Faryna ◽  
Jan Dutkiewicz
Keyword(s):  
Solid Solution ◽  
Melt Spinning ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Dendritic Microstructure ◽  
X Ray ◽  
Cu Alloys ◽  
Transmission Electron ◽  
Cast Alloys ◽  
Rapidly Solidified

The effect of rapid solidification on the microstructure of Al-Zn-Mg-Cu alloys with 8 wt.% Zn-2 wt.% Mg-2.3 wt.% Cu and 0.2 or 0.5 wt.% of Zr additions were investigated using X-ray diffraction measurements (XRD), scanning (SEM) and transmission electron microscopy (TEM) combined with energy dispersive X-ray (EDX) microanalysis. Rapidly solidified ribbons with thickness of 70-100 m were performed by melt spinning technique. The mould cast alloys as well as the melt spun ribbons revealed dendritic microstructure of (Al) solid solution and η Mg(Zn,Cu)2 phase in interdendritic areas. The refinement of the microstructure and reduction of the volume fraction of the η phase up to 1.7%, as compared to 4% in the mould cast alloys was observed in the ribbons. Copper dissolution up to about 20 wt % in the η phase causes a decrease of the lattice parameters. The Al3Zr primary precipitates were observed in the mould cast alloy containing 0.5 wt % of Zr while in the ribbons all zirconium dissolved in the aluminium solid solution.

scholarly journals Effect of Micro Solidification Crack on Mechanical Performance of Remote Laser Welded AA6063 Fillet Lap Joint in Automotive Battery Tray Construction

2021 ◽  
Vol 11 (10) ◽  
pp. 4522
Author(s):  
Tianzhu Sun ◽  
Pasquale Franciosa ◽  
Conghui Liu ◽  
Fabio Pierro ◽  
Darek Ceglarek
Keyword(s):  
Laser Welding ◽  
Fusion Zone ◽  
Aluminium Alloys ◽  
Mechanical Performance ◽  
Lap Joints ◽  
Fatigue Durability ◽  
Micro Cracks ◽  
Remote Laser Welding ◽  
Weld Fatigue ◽  
Weld Root

Remote laser welding (RLW) has shown a number of benefits of joining 6xxx aluminium alloys such as high processing speed and process flexibility. However, the crack susceptibility of 6xxx aluminium alloys during RLW process is still an open problem. This paper experimentally assesses the impact of transverse micro cracks on joint strength and fatigue durability in remote laser welding of AA6063-T6 fillet lap joints. Distribution and morphology of transverse micro cracks were acquired by scanning electron microscope (SEM) on cross-sections. Grain morphology in the weld zone was determined by electron backscatter diffraction (EBSD) while static tensile and dynamic fatigue tests were carried out to evaluate weld mechanical performance. Results revealed that increasing welding speed from 2 m/min to 6 m/min did not introduce additional transverse micro cracks. Additionally, welding at 2 m/min resulted in tensile strength improvement by 30% compared to 6 m/min due to the expansion of fusion zone, measured by the throat thickness, and refinement of columnar grains near fusion lines. Furthermore, the weld fatigue durability is significantly higher when fracture occurs in weld root instead of fusion zone. This can be achieved by increasing weld root angle with optimum weld fatigue durability at around 55°.

The scandium-rich indide Sc50Pt13.47In2.53

2020 ◽  
Vol 75 (6-7) ◽  
pp. 715-720 ◽  
Author(s):  
Nataliya L. Gulay ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Phases ◽  
Subsequent Annealing ◽  
Induction Melting ◽  
X Ray

AbstractThe scandium-rich indide Sc50Pt13.47In2.53 was obtained by induction melting of the elements and subsequent annealing. The structure of Sc50Pt13.47In2.53 has been refined from single-crystal X-ray diffractometer data: Fm$\overline{3}$, a = 1774.61(3) pm, wR2 = 0.0443, 1047 F2 values and 35 variables. Sc50Pt13.47In2.53 is isopointal with the intermetallic phases Sc50Co12.5In3.5, Sc50Rh13.3In2.7, Sc50Ir13.6In2.4, Ag7+xMg26−x and Ga4.55Mg21.85Pd6.6 (Pearson code cF264 and Wyckoff sequence ih2fecba). Two of the eight crystallographic sites in the structure show mixed occupancies: M1 (≡Pt20.70In10.30) and M2 (≡Pt30.76In20.24). The structure contains four basic polyhedra: M2@Sc8 cubes, Pt1@Sc10 sphenocorona and slightly distorted M1@Sc12 and In3@Sc12 icosahedra. The polyhedra are condensed via common scandium corners and edges. The various Sc–Sc distances range from 302–334 pm and are indicative of substantial Sc–Sc bonding, stabilizing the Sc50Pt13.47In2.53 structure.

scholarly journals Joining of SiO2 glass and 316L stainless steel using Bi–Ag-based active solders

2020 ◽  
Vol 56 (4) ◽  
pp. 3444-3454
Author(s):  
Felix Weber ◽  
Markus Rettenmayr
Keyword(s):  
Stainless Steel ◽  
Cross Sections ◽  
316L Stainless Steel ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Reaction Products ◽  
Cast State ◽  
Metallic Component ◽  
X Ray ◽  
Solder Interface

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.

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