scholarly journals Formation of Die Soldering and the Influence of Alloying Elements on the Intermetallic Interface

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1580
Author(s):  
Marius Kohlhepp ◽  
Peter J. Uggowitzer ◽  
Marc Hummel ◽  
Heinz Werner Höppel
Keyword(s):  
Pure Aluminum ◽  
Intermetallic Phase ◽  
Al Alloy ◽  
Aluminum Casting ◽  
Β Phase ◽  
Alsi Alloy ◽  
Casting Industry ◽  
Die Castings ◽  
3Si2 Phase ◽  
Intermetallic Layers

Die soldering of die castings is a serious problem in the aluminum casting industry. The precise mechanism, the influence of the alloy composition, and the options for prevention have not yet been fully elaborated. A well-established solution for alloys with low iron content is the addition of manganese. However, up to 0.8 wt.% is necessary, which increases the amount of brittle phases in the material and consequently reduces ductility. Immersion tests with 1.2343 tool steel and pure aluminum as well as a hypoeutectic AlSi-alloy with Mn, Mo, Co, and Cr additions were carried out to systematically investigate the formation of die soldering. Three different intermetallic layers and a scattered granular intermetallic phase formed at the interface between steel and Al-alloy after immersion into the melt for a duration of 6 min at 710 °C. The combined presence of the irregular, needle-shaped β-Al5FeSi phase and the surrounding alloy was responsible for the bond between the two components. Mn and Mo inhibited the formation of the β-phase, and instead promoted the αC-Al15(Fe,X)3Si2 phase. This led to an evenly running boundary to the AlSi-alloy and thus prevented bonding. Cr has proven to be the most efficient addition against die soldering, with 0.2 wt.% being sufficient. Contrary to the other elements investigated, Cr also reduced the thickness of the intermetallic interface.

scholarly journals Experimental and numerical investigations of oxide-related defects in Al alloy gravity die castings

2021 ◽  
Author(s):  
Giulia Scampone ◽  
Raul Pirovano ◽  
Stefano Mascetti ◽  
Giulio Timelli
Keyword(s):  
Fluid Dynamic ◽  
Casting Process ◽  
Numerical Code ◽  
Al Alloy ◽  
Numerical Investigations ◽  
Die Casting Process ◽  
Experimental Findings ◽  
Die Castings ◽  
Filling And Solidification ◽  
Image Analysis Techniques

AbstractThis research aimed to study the formation and distribution of oxide-related defects in the gravity die casting process of an AlSi7Cu0.5Mg alloy by using experimental and numerical investigations. Metallographic and image analysis techniques were conducted to map the distribution of oxide inclusions inside the casting at the microscopic level. Numerical simulations were used to analyse the filling and solidification stages, and to foresee the turbulence of the melt and the formation of the oxide defects. The results show that most of the defects were correlated with the oxide layers or bubbles entrained inside the liquid metal. The accuracy of the numerical code in simulating the metal fluid-dynamic behaviour and the heat transfer was verified, and the results were in agreement with the experimental findings. The numerical distribution of defects was consistent with the experimental results, proving that the model successfully predicted the formation of oxide-related defects.

scholarly journals Al-Ti-B4C materials obtained by high-temperature synthesis and used as a master-alloy for aluminum

2018 ◽  
Vol 243 ◽  
pp. 00010 ◽  
Author(s):  
Ilya Zhukov ◽  
Vladimir Promakhov ◽  
Yana Dubkova ◽  
Alexey Matveev ◽  
Mansur Ziatdinov ◽  
...  
Keyword(s):  
High Temperature ◽  
Burning Rate ◽  
Powder Mixture ◽  
Pure Aluminum ◽  
Al Alloy ◽  
Initial Powder ◽  
Temperature Synthesis ◽  
Al Content ◽  
High Temperature Synthesis ◽  
Al Powder

The paper presents microstructure, composition, and burning rate of Al alloy produced by high-temperature synthesis (SHS) from powder mixture Al-Ti-B4C with different concentration of Al powder. It has been established that the phase composition of materials obtained at gas-free combustion includes TiB2, Al, and TiC. It is shown that Al content growth powder in initial Al-Ti- B4C mixture from 7.5 to 40 wt.% reduces the burning rate of the powder from 9*10-3 to 1.8*10-3 m/s. For the system consisting of 60 wt.% of (Ti + B4C) and 40 wt.% of Al there is the increase in the porosity of the compacted initial powder mixture from 30 to 51 and reduction in the burning rate from 1.8 * 10-3 to 1 * 10-3 m/s. The introduction of 0.2 wt.% of the obtained SHS materials into the melt of pure aluminum causes reduction of the grain size of the resulting alloy from 1200 to 410 μm.

scholarly journals The Effect of Hydrogen on Pore Formation in Aluminum Alloy Castings: Myth Versus Reality

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 368 ◽  
Author(s):  
Murat Tiryakioğlu
Keyword(s):  
Pore Formation ◽  
Liquid Aluminum ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Fundamental Change ◽  
Aluminum Casting ◽  
Solid Aluminum ◽  
Alloy Castings ◽  
Casting Industry

The solubility of hydrogen in liquid and solid aluminum is reviewed. Based on classical nucleation theory, it is shown that pores cannot nucleate either homogeneously or heterogeneously in liquid aluminum. Results of in situ studies on pore formation show that pores appear at low hydrogen supersaturation levels, bypassing nucleation completely. The results are explained based on the bifilm theory introduced by Prof. John Campbell, as this theory is currently the most appropriate, and most likely, the only mechanism for pores to form. Examples for the effect of hydrogen on pore formation are given by using extreme data from the literature. It is concluded that a fundamental change in how hydrogen is viewed is needed in aluminum casting industry.

On the electrochemical behavior of Cu–16%Zn–6.5%Al alloy containing the β′-phase (martensite) in borate buffer

2013 ◽  
Vol 107 ◽  
pp. 238-247 ◽  
Author(s):  
M. Blanco ◽  
J.T.C. Barragan ◽  
N. Barelli ◽  
R.D. Noce ◽  
C.S. Fugivara ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Borate Buffer ◽  
Al Alloy ◽  
Β Phase

scholarly journals Ultrasonic Sensors-Assisted Corrosion Studies on Surface Coated AlSi9Cu3 Alloy Die Castings

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 85
Author(s):  
Yuh-Chung Hu ◽  
Senthil Kumaran Selvaraj ◽  
Manivannan Subramanian ◽  
Kathiravan Srinivasan ◽  
Srinivasan Narayanan
Keyword(s):  
Corrosion Resistance ◽  
Die Casting ◽  
Pure Aluminum ◽  
Salt Spray ◽  
Salt Spray Test ◽  
Al Alloy ◽  
Neutral Salt ◽  
Powder Coatings ◽  
Acrylic Paint ◽  
Epoxy Primer

A novel phenomenon known as Industry X.0 is becoming extremely popular for digitizing and reinventing business organizations through the adaption of rapid and dynamic technological, innovational, and organizational changes for attaining the profitable revenue. This work investigates the die-casted commercially pure aluminum alloyed with 9% silicon and 3% copper (AlSi9Cu3) that is produced through the gravity die casting process. Further, the degradation of surface coating on die-casted AlSi9Cu3 alloy was explored. The acrylic paint electrodeposition (ED) coat, 2-coat polyester without primer and 3-coat polyester with epoxy primer powder coatings were used in this study. Moreover, the 3.5 wt.% of sodium chloride (3.5 wt.% of NaCl) test solution was used for electrochemical and salt spray test and the tools used to assess electrochemical properties were electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and neutral salt spray test (NSS). The microstructure of AlSi9Cu3 after corrosion exposure was investigated; also, the microstructure of coated and uncoated AlSi9Cu3 samples was analyzed by SEM microscopy after corrosion exposure. Besides, the electrochemical studies were also carried out on the Al alloy die casting. It was found that acrylic paint ED coatings exhibited higher corrosion resistance than 2-coat polyester without primer & 3-coat polyester with epoxy primer powder coatings. Acrylic paint ED coating showed higher corrosion resistance in AC and a lower value in DC and 3-coat polyester with epoxy primer powder coating displayed higher corrosion resistance in DC and a lower value in AC.

Microstructure, Texture and Mechanical Properties of Al Alloy A380 Prepared by Directional Solidification Method

2019 ◽  
Vol 287 ◽  
pp. 18-23
Author(s):  
Hemant Borkar ◽  
Salem Seifeddine ◽  
Anders E.W. Jarfors
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Directional Solidification ◽  
Solidification Rate ◽  
Al Alloy ◽  
Secondary Dendrite Arm Spacing ◽  
Β Phase ◽  
Cu Alloy ◽  
Eutectic Si ◽  
The One

The mechanical properties of Al-Si alloys are affected by several microstructural features such as secondary dendrite arm spacing (SDAS), size and shape of eutectic Si-particles, presence of intermetallics as well as by porosity. In the current study, Al-Si-Cu alloy A380 was prepared by a unique directional solidification method to produce samples with two different SDAS of 9 μm and 27 μm. The lower solidification rate resulted in larger SDAS, larger grain size, larger eutectic Si and larger intermetallics including Fe-rich β phase. The microstructure with higher solidification rate was found to be finer and more homogeneous with smaller eutectic Si and intermetallics. The specimen with larger SDAS exhibited stronger texture than the one with smaller SDAS. The specimen with smaller SDAS showed improved mechanical properties including YS, UTS and ductility.

The Intermetallic Phases in Sand Casting Magnesium Alloys for Elevated Temperature

2011 ◽  
Vol 690 ◽  
pp. 214-217 ◽  
Author(s):  
Andrzej Kiełbus ◽  
Tomasz Rzychoń
Keyword(s):  
Solid Solution ◽  
Elevated Temperature ◽  
Grain Boundaries ◽  
Magnesium Alloys ◽  
Solution Structure ◽  
Intermetallic Phase ◽  
Intermetallic Phases ◽  
Phase Identification ◽  
Al Alloy ◽  
Cast Microstructure

In the present article, the phase identification of four magnesium alloys: Mg-9wt%Al, Mg-8wt%Al-2wt%Ca-0.5wt%Sr, Mg-5wt%Y-4wt%RE and Mg-3wt%Nd-1wt%Gd were studied. The results showed that Mg-9wt%Al alloy contains only the Mg17Al12 intermetallic phase in α-Mg matrix. As-cast microstructure of Mg-8wt%Al-2wt%Ca-0.5wt%Sr alloy consist of α-Mg matrix with (Al,Mg)2Ca and (Al,Mg)4Sr phases. The Mg-5wt%Y-4wt%RE alloy showed several phases. This alloy was characterized by a solid solution structure α-Mg with eutectic α-Mg + Mg14Y2Nd on grain boundaries. The precipitates of MgY, Mg2Y, Mg24Y5 phases have been also observed. The Mg-3wt%Nd-1wt%Gd alloy composed mainly of a solid solution structure α-Mg with eutectic α-Mg + Mg3(Nd,Gd) on the grain boundaries. The regular precipitates of MgGd3 phase have been also observed.

The Influence of Metallic Addition on Fluidity of Aluminum (LM6) Alloy

2013 ◽  
Vol 465-466 ◽  
pp. 954-957
Author(s):  
Roslee Ahmad ◽  
R. Sadeghi ◽  
M.B.A. Asmael ◽  
H. Mohamad ◽  
Zawati Harun ◽  
...  
Keyword(s):  
Phase Diagram ◽  
Intermetallic Phase ◽  
Volume Ratio ◽  
The Other ◽  
Interfacial Region ◽  
Β Phase ◽  
Α Phase ◽  
Cr Addition ◽  
And Shifts ◽  
Fluidity Test

The effect of Cr addition on the fluidity of aluminum (LM6) alloy has been investigated by spiral fluidity test. Presence of 0.1 wt.% Cr decreased fluidity of melt due to formation of sludge. In fact Cr changes the morphology of the intermetallic phase from β-intermetallics less harmful polyhedral morphology (α-intermetallics). The β-phases have largest surface to volume ratio, hence they have the largest interfacial region with the melt and are the most detrimental intermetallic to drop off the fluidity. In Cr-containing alloys the effect of α-phase is less detrimental than β-phase to the fluidity. On the other hand sludge formation and consuming Si and shifts the local chemical composition of the melt to the aluminum side of the phase diagram which has lower fluidity than eutectic and hypereutectic compositions.

Safety Guarantee of Al Alloy Die Castings for the Car Component Made by Plastic Working

2003 ◽  
Vol 2003 (0) ◽  
pp. 87-88
Author(s):  
Hideto SUZUKI ◽  
Tsuyoshi SHIRATORI ◽  
Masashi NAKAMURA ◽  
Masato SATO
Keyword(s):  
Al Alloy ◽  
Plastic Working ◽  
Die Castings ◽  
Car Component
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