scholarly journals Recent state of Japanese Al Alloy casting industry

1986 ◽  
Vol 36 (10) ◽  
pp. 607-608
Author(s):  
Tsukasa Iwanami
Keyword(s):  
Al Alloy ◽  
Alloy Casting ◽  
Casting Industry

Grain Refinement of a Large-Scale Al Alloy Casting by Introducing the Multiple Ultrasonic Generators During Solidification

2016 ◽  
Vol 47 (8) ◽  
pp. 3790-3796 ◽  
Author(s):  
Ruiqing Li ◽  
Zhilin Liu ◽  
Fang Dong ◽  
Xiaoqian Li ◽  
Pinghu Chen
Keyword(s):  
Grain Refinement ◽  
Large Scale ◽  
Al Alloy ◽  
Alloy Casting

scholarly journals Possible Effects and Mechanisms of Ultrasonic Cavitation on Oxide Inclusions during Direct-Chill Casting of an Al Alloy

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 814 ◽  
Author(s):  
Yun Zhang ◽  
Ruiqing Li ◽  
Xiaoqian Li ◽  
Yilong Yang ◽  
Pinghu Chen ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Large Scale ◽  
Flow Behavior ◽  
Direct Chill ◽  
Al Alloy ◽  
Aluminum Alloy Casting ◽  
Hot Top ◽  
Alloy Casting ◽  
Continuous Ingot ◽  
Ultrasonic Assisted

Oxide films or inclusions can reduce the continuity and integrity of materials and they always lead to a significant reduction in the mechanical properties of an aluminum alloy. They can greatly reduce the plastic flow behavior of materials, thus affecting the subsequent processing performance. Therefore, an effective ultrasonic assisted preparation technology has been applied to industrial manufacturing of large-scale aluminum alloy ingots (with diameter: Φ = 1250 mm and height: h = 3750 mm). However, the mechanisms of ultrasonic purification on the large-scale ingots are not clear. Therefore, a number of aluminum alloy casting experiments were carried out to produce a conventional hot top semi-continuous ingot (CHTI) and an ultrasonic hot top semi-continuous ingot (UHTI) in this work. The microstructures of CHTI and UHTI were analyzed by optical microscopy (OM) and scanning electron microscopy (SEM). The results indicated that there were some oxide film defects in the CHTI but some finely dispersed inclusion particles were discovered in the UHTI. The X-ray diffraction (XRD) data showed that the component of inclusion was Al2O3. According to the different cavitation effects of the different areas of the molten aluminum, the process of ultrasonic purification was divided into three periods and the mechanisms in each period were separately studied.

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.

Application of Microstructure Simulation by Modified CA Method to Al Alloy Casting Production

2009 ◽  
Vol 618-619 ◽  
pp. 199-202 ◽  
Author(s):  
Qing Yan Xu ◽  
Bin Li ◽  
Bai Cheng Liu
Keyword(s):  
Solidification Process ◽  
Grain Structure ◽  
Solute Diffusion ◽  
Al Alloy ◽  
Dendritic Microstructure ◽  
Turbine Wheel ◽  
Alloy Casting ◽  
Microstructure Simulation ◽  
Grain Growth Model ◽  
Casting Production

Aluminum casting is widely used in aeronautical, automobile and other industries nowadays. The Cellular Automaton (CA) method was modified to simulate the microstructure evolution of Al alloy casting. Simulated program code was developed and applied into Al casting production. A nucleation model was investigated based upon the experimental data. The solute diffusion in the liquid and solid phases was also considered in developing a grain growth model. With the developed models, not only grain structure but also dendritic microstructure can be predicted during the solidification process. The microstructure simulation of the Al alloy turbine wheel was studied in detail.

Effets of surfaces on precipitate morphology in irradiated thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 654-655
Author(s):  
D.I. Potter ◽  
A. Taylor
Keyword(s):  
Ion Irradiation ◽  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
Al Alloy ◽  
Bright Field Image ◽  
Dislocation Loops ◽  
Precipitate Morphology ◽  
Thin Foils

Thermal aging of Ni-12.8 at. % A1 and Ni-12.7 at. % Si produces spatially homogeneous dispersions of cuboidal γ'-Ni3Al or Ni3Si precipitate particles arrayed in the Ni solid solution. We have used 3.5-MeV 58Ni+ ion irradiation to examine the effect of irradiation during precipitation on precipitate morphology and distribution. The nearness of free surfaces produced unusual morphologies in foils thinned prior to irradiation. These thin-foil effects will be important during in-situ investigations of precipitation in the HVEM. The thin foil results can be interpreted in terms of observations from bulk irradiations which are described first.Figure 1a is a dark field image of the γ' precipitate 5000 Å beneath the surface(∿1200 Å short of peak damage) of the Ni-Al alloy irradiated in bulk form. The inhomogeneous spatial distribution of γ' results from the presence of voids and dislocation loops which can be seen in the bright field image of the same area, Fig. 1b.

A microscopic marker experiment study on high temperature oxidation of Ni-Al alloy

1986 ◽  
Vol 44 ◽  
pp. 514-515
Author(s):  
Shou-kong Fan
Keyword(s):  
Transport Mechanism ◽  
High Temperature Oxidation ◽  
Transverse Section ◽  
Al Alloy ◽  
Metal Interface ◽  
Electron Microscopic ◽  
Temperature Oxidation ◽  
Analytical Electron ◽  
Microscopic Studies ◽  
First Time

Transmission and analytical electron microscopic studies of scale microstructures and microscopic marker experiments have been carried out in order to determine the transport mechanism in the oxidation of Ni-Al alloy. According to the classical theory, the oxidation of nickel takes place by transport of Ni cations across the scale forming new oxide at the scale/gas interface. Any markers deposited on the Ni surface are expected to remain at the scale/metal interface after oxidation. This investigation using TEM transverse section techniques and deposited microscopic markers shows a different result,which indicates that a considerable amount of oxygen was transported inward. This is the first time that such fine-scale markers have been coupled with high resolution characterization instruments such as TEM/STEM to provide detailed information about evolution of oxide scale microstructure.

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