scholarly journals Interface Reaction between Molten Al99.7 Aluminum Alloy and Various Tool Steels

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7708
Author(s):  
Maja Vončina ◽  
Tilen Balaško ◽  
Jožef Medved ◽  
Aleš Nagode
Keyword(s):  
Aluminum Alloy ◽  
Intermetallic Layer ◽  
Interface Reaction ◽  
Casting Process ◽  
Ferrite Matrix ◽  
Tool Steels ◽  
Forming Process ◽  
Scanning Calorimetry ◽  
Thermo Calc Software ◽  
The Stability

During the die-casting process as well as the hot forming process, the tool is subjected to complex thermal, mechanical, and chemical stresses that can cause various types of damage to different parts of the tool. This study was carried out to determine the resistance of various tool steels, i.e., UTOPMO1, HTCS-130, and W600, in molten Al99.7 aluminum alloy at a temperature of 700 °C. The formation kinetics of the interaction layer between the molten aluminum and tool steels was studied using differential scanning calorimetry. Light and field-emission scanning electron microscopy were used to analyze the thickness and nature of the interaction layers, while thermodynamic calculations using the Thermo-Calc software were used to explain the results. The stability of the HTCS-130 and W600 tool steels is better than the stability of the UTOPMO1 tool steel in the molten Al99.7 aluminum. Two interaction layers were formed, which in all cases indicate an intermetallic Al13Fe4 layer near the aluminum alloy and an intermetallic Al5Fe2 layer near the tool steels, containing small round carbides. It was confirmed that Ni reduces the activity of aluminum in the ferrite matrix and causes a reduction in the thickness of the intermetallic layer.

scholarly journals Characterization of the Role of Squeeze Casting on the Microstructure and Mechanical Properties of the T6 Heat Treated 2017A Aluminum Alloy

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
S. Souissi ◽  
N. Souissi ◽  
H. Barhoumi ◽  
M. ben Amar ◽  
C. Bradai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Squeeze Casting ◽  
Applied Pressure ◽  
High Strength ◽  
Casting Process ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties

In this study, the effects of squeeze casting process and T6 heat treatment on the microstructure and mechanical properties of 2017A aluminum alloy were investigated with scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), differential scanning calorimetry (DSC), and microhardness and tensile tests. The results showed that this alloy contained α matrix, θ-Al2Cu, and other phases. Furthermore, the applied pressure and heat treatment refines the microstructure and improve the ultimate tensile strength (UTS) to 296 MPa and the microhardness to 106 HV with the pressure 90 MPa after ageing at 180°C for 6 h. With ageing temperature increasing to 320°C for 6 h, the strength of the alloy declines slightly to 27 MPa. Then, the yield strength drops quickly when temperature reaches over 320°C. The high strength of the alloy in peak-aged condition is caused by a considerable amount of θ′ precipitates. The growth of θ′ precipitates and the generation of θ phase lead to a rapid drop of the strength when temperature is over 180°C.

scholarly journals Effects of Homogenization Conditions on the Microstructure Evolution of Aluminium Alloy EN AW 8006

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 419
Author(s):  
Maja Vončina ◽  
Kristijan Kresnik ◽  
Darja Volšak ◽  
Jožef Medved
Keyword(s):  
Aluminium Alloy ◽  
Thermodynamic Simulation ◽  
Casting Process ◽  
Optical Microscope ◽  
Scanning Calorimetry ◽  
Energy Dispersion Spectrometer ◽  
Thermo Calc Software ◽  
Equilibrium Solidification ◽  
Equilibrium Phases ◽  
Non Equilibrium

The industrial production of products, such as foil and aluminium alloy strips, begins with the production of semi-finished products in the form of slabs. These are produced by the continuous casting process, which is quick and does not allow the equilibrium conditions of solidification. Non-homogeneity—such as micro and macro segregation, non-equilibrium phases and microstructural constituents, as well as stresses arising during non-equilibrium solidification—are eliminated by means of homogenization annealing. In this way, a number of technological difficulties in the further processing of semi-finished products can be avoided. The aim of this research was the optimization of the homogenization annealing of the EN AW 8006 alloy. With the Thermo-Calc software, a thermodynamic simulation of equilibrium and non-equilibrium solidification was performed. Differential scanning calorimetry (DSC) was performed on selected samples in as-cast state and after various regimes of homogenization annealing and was used for the simulation of homogenization annealing. Using an optical microscope (OM), a scanning electron microscope (SEM) and an energy dispersion spectrometer (EDS), the microstructure of the samples was examined. Based on the results, it was concluded that homogenization annealing has already taken place after 8 h at 580 °C to the extent, that the material is then suitable for further processing.

scholarly journals Integration of Stable Ionic Liquid-Based Nanofluids into Polymer Membranes. Part I: Membrane Synthesis and Characterization

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 607
Author(s):  
Carolina Hermida-Merino ◽  
Fernando Pardo ◽  
Gabriel Zarca ◽  
João M. M. Araújo ◽  
Ane Urtiaga ◽  
...  
Keyword(s):  
Polymer Membranes ◽  
Small Addition ◽  
Polymeric Membranes ◽  
Synthesis And Characterization ◽  
Complete Disappearance ◽  
Optical Profilometry ◽  
Scanning Calorimetry ◽  
Exfoliated Graphene ◽  
The Stability ◽  
Scanning Electron

In this work, polymeric membranes functionalized with ionic liquids (ILs) and exfoliated graphene nanoplatelets (xGnP) were developed and characterized. These membranes based on graphene ionanofluids (IoNFs) are promising materials for gas separation. The stability of the selected IoNFs in the polymer membranes was determined by thermogravimetric analysis (TGA). The morphology of membranes was characterized using scanning electron microscope (SEM) and interferometric optical profilometry (WLOP). SEM results evidence that upon the small addition of xGnP into the IL-dominated environment, the interaction between IL and xGnP facilitates the migration of xGnP to the surface, while suppressing the interaction between IL and Pebax®1657. Fourier transform infrared spectroscopy (FTIR) was also used to determine the polymer–IoNF interactions and the distribution of the IL in the polymer matrix. Finally, the thermodynamic properties and phase transitions (polymer–IoNF) of these functionalized membranes were studied using differential scanning calorimetry (DSC). This analysis showed a gradual decrease in the melting point of the polyamide (PA6) blocks with a decrease in the corresponding melting enthalpy and a complete disappearance of the crystallinity of the polyether (PEO) phase with increasing IL content. This evidences the high compatibility and good mixing of the polymer and the IoNF.

scholarly journals Challenges in the Forging of Steel-Aluminum Bearing Bushings

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 803
Author(s):  
Bernd-Arno Behrens ◽  
Johanna Uhe ◽  
Tom Petersen ◽  
Christian Klose ◽  
Susanne E. Thürer ◽  
...  
Keyword(s):  
Intermetallic Layer ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Internal Diameter ◽  
External Diameter ◽  
Forming Process ◽  
High Deformation ◽  
Eds Analysis ◽  
Steel Aisi ◽  
Metallurgical Bond

The current study introduces a method for manufacturing steel–aluminum bearing bushings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing FexAly phase in the resulting intermetallic layer.

scholarly journals An Evaluation of the Stability of Mould Flux Properties in the Process of Continuous Steel Casting

2017 ◽  
Vol 62 (2) ◽  
pp. 885-889 ◽  
Author(s):  
J. Falkus
Keyword(s):  
Process Parameters ◽  
Liquidus Temperature ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Time Intervals ◽  
Equal Time ◽  
Industrial Experiments ◽  
Mould Flux ◽  
Steel Cast ◽  
The Stability

AbstractThis paper presents research on the mould slag formed on the basis of two mould fluxes. In the conducted industrial experiments, slag was sampled in equal time intervals between adding subsequent portions of mould flux. The research focused on the an evaluation of the stability of slag parameters by assessing the change in its liquidus temperature. It was shown that a mould flux needs to be assessed individually taking into account the casting process parameters and the steel cast grade.

Effects on the microstructure and mechanical properties of Sn-0.7Cu lead-free solder with the addition of a small amount of magnesium

2016 ◽  
Vol 23 (6) ◽  
pp. 641-647
Author(s):  
Her-Yueh Huang ◽  
Chung-Wei Yang ◽  
Yu-Chang Peng
Keyword(s):  
Mechanical Properties ◽  
Aging Process ◽  
Intermetallic Layer ◽  
Eutectic Structure ◽  
Contact Angles ◽  
Solidification Structure ◽  
Lead Free Solder ◽  
Bulk Alloy ◽  
Scanning Calorimetry ◽  
Free Solder

AbstractThe influence of a small amount of magnesium (only 0.01 wt.%) added to the Sn-0.7Cu solder alloy during the aging process of microstructural evolution is studied along with the mechanical properties of the alloy. The experimental results indicate that the addition of magnesium decreases the tensile strength of the solders but improves their elongation. The solidification structure of eutectic Sn-0.7Cu consists of β-Sn, and the eutectic structure, which has extremely fine intermetallic nodules, Cu6Sn5, is located in the interdendritic region. When the magnesium is added to the Sn-0.7Cu alloy, the Sn dendrites become slightly coarser; in comparison, the melting point of the Sn-0.7Cu-0.01Mg alloy decreased by 2°C for the differential scanning calorimetry results of bulk alloy samples. Sn-0.7Cu-0.01Mg exhibits the lowest contact angles and the widest spreading areas. After aging, the Sn-0.7Cu and Sn-0.7Cu-0.01Mg solders show significant changes in strength, mainly because of the obvious increase in the thickness of the Cu6Sn5 intermetallic layer.

scholarly journals Deformation Characteristics and Microstructure Analysis of Aluminum Alloy Component with Complex Shape by Cold Orbital Forming

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 808
Author(s):  
Wei Feng ◽  
Chaoyi Jin ◽  
Jiadong Deng ◽  
Wuhao Zhuang
Keyword(s):  
Aluminum Alloy ◽  
Complex Shape ◽  
Fe Simulation ◽  
Effective Strain ◽  
Electron Back Scatter Diffraction ◽  
Main Body ◽  
Deformation Characteristics ◽  
Alloy Component ◽  
Forming Process ◽  
Orbital Forming

This work aimed to study the deformation characteristics and microstructure of AA6063 aluminum alloy component with complex shape manufactured by cold orbital forming processing. The material flowing behavior was analyzed by Finite Element (FE) simulation and forming experiments were carried out using bar blank with different lengths. The microstructure of the boss zone cut from the formed samples was observed using scanning electron microscopy (SEM) and electron back-scatter diffraction (EBSD). FE simulation and experiment results both showed the aluminum base can be formed using cold orbital forming process. The distributions of the effective strain of the component with different blank lengths were almost the same, and the effective strain was bigger at the boss and the flash as the forming finished. The material flow is complex, especially in the boss, and the folding defect was observed at the root of the boss. The distribution of Mg2Si strengthening precipitate is more homogeneous in the matrix, has a different shape, and shows directivity at different position of boss zone. The grains are elongated, and the extent is different at different positions of the boss zone after cold orbital forming, and the crystal orientation discrepancy is smaller in the component main body and bigger in the boss zone. Subsequent forming process and blank optimization need to be further researched to improve forming quality.

scholarly journals Thermal Properties and Non-Isothermal Crystallization Kinetics of Poly (δ-Valerolactone) and Poly (δ-Valerolactone)/Titanium Dioxide Nanocomposites

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 452 ◽  
Author(s):  
Waseem Saeed ◽  
Abdel-Basit Al-Odayni ◽  
Abdulaziz Alghamdi ◽  
Ali Alrahlah ◽  
Taieb Aouak
Keyword(s):  
Titanium Dioxide ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Three Dimensional ◽  
Degree Of Crystallinity ◽  
Simultaneous Occurrence ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics ◽  
The Stability ◽  
Kinetics Of

New poly (δ-valerolactone)/titanium dioxide (PDVL/TiO2) nanocomposites with different TiO2 nanoparticle loadings were prepared by the solvent-casting method and characterized by Fourier transform infra-red, differential scanning calorimetry, X-ray diffraction and scanning electron microscopy, and thermogravimetry analyses. The results obtained reveal good dispersion of TiO2 nanoparticles in the polymer matrix and non-formation of new crystalline structures indicating the stability of the crystallinity of TiO2 in the composite. A significant increase in the degree of crystallinity was observed with increasing TiO2 content. The non-isothermal crystallization kinetics of the PDVL/TiO2 system indicate that the crystallization process involves the simultaneous occurrence of two- and three-dimensional spherulitic growths. The thermal degradation analysis of this nanocomposite reveals a significant improvement in the thermal stability with increasing TiO2 loading.

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