Effects of Mold Temperature and Casting Temperature on Hot Cracking in Al-4.5 wt.% Cu Alloy

2013 ◽  
Vol 747 ◽  
pp. 623-626
Author(s):  
R. Burapa ◽  
S. Rawangwong ◽  
J. Chatthong ◽  
Worapong Boonchouytan
Keyword(s):  
High Resistance ◽  
Copper Alloys ◽  
Mold Temperature ◽  
Hot Cracking ◽  
The Other ◽  
Casting Temperature ◽  
Experimental Conditions ◽  
Cu Alloy ◽  
Aluminum Copper Alloys ◽  
Cracking Tendency

Hot cracking is an important defect that occurs during solidification of aluminum-copper alloys. In this present work, the effects of mold temperature and casting temperature on hot cracking in the Al-4.5 wt.% Cu alloy has been studied using a ring mold for hot cracking assessment. For the experimental conditions, three mold temperatures between 150 and 350°C and three casting temperatures between 670 and 770°C were studied and Al-7 wt.% Si alloy was used as reference for comparison. The results showed Al-7 wt.% Si alloy has high resistance to hot cracking and no hot cracking forms under three different mold temperatures, while Al-4.5 wt.% Cu alloy shows significant hot cracking tendency under the same casting conditions. The severity of hot cracking in Al-4.5 wt.% Cu alloy decreased significantly with increasing the mold temperature and decreasing the casting temperature. On the other hand, an increasing casting temperature resulted in severer hot cracking in Al-4.5 wt.% Cu alloy.

Numerical Modeling of Microporosity Formation in Aluminum-Rich Aluminum-Copper Alloys in Microgravity Conditions

2000 ◽  
Author(s):  
M. Xiong ◽  
A. V. Kuznetsov
Keyword(s):  
Copper Alloys ◽  
Heat Transfer Fluid ◽  
Gas Phases ◽  
Alloy Casting ◽  
Cu Alloy ◽  
Aluminum Copper Alloys ◽  
Three Phase ◽  
Microgravity Conditions ◽  
Parametric Analyses ◽  
Solid Liquid

Abstract The microporosity formation in a vertical unidirectionally solidifying Al-4.1%Cu alloy casting is modeled in both microgravity and standard gravity as well as in the conditions of decreased (Moon, Mars) and increased (Jupiter) gravity. Due to the unique opportunities offered by a low-gravity environment (absence of metallostatic pressure and of natural convection in the solidifying alloy) future microgravity experiments will significantly contribute to attaining a better physical understanding of the mechanisms of microporosity formation. One of the aims of the present theoretical investigation is to predict what microporosity patterns will look like in microgravity in order to help plan a future microgravity experiment. To perform these simulations, the authors suggest a novel three-phase model of solidification that accounts for the solid, liquid, and gas phases in the mushy zone. This model accounts for heat transfer, fluid flow, macrosegregation, and microporosity formation in the solidifying alloy. Special attention is given to the investigation of the influence of microporosity formation on the inverse segregation. Parametric analyses for different initial hydrogen concentrations and different gravity conditions are carried out.

scholarly journals Ultrasonic Vibration as a Primary Mixing Tool in Accelerating Aluminum–Copper Alloys Preparation from Their Pure Elements

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 781
Author(s):  
Abdulsalam Muhrat ◽  
Hélder Puga ◽  
Joaquim Barbosa
Keyword(s):  
Ultrasonic Vibration ◽  
Copper Alloys ◽  
Grain Refining ◽  
Alloying Element ◽  
Experimental Conditions ◽  
Melt Temperature ◽  
Cu Alloys ◽  
Aluminum Copper Alloys ◽  
Main Factor

In this study, ultrasonic vibration (USV) was evaluated in preparation of Al–8wt.%Cu alloys at a lab-scale. Moreover, the role of Ti–6Al–4V sonotrode erosion and its contribution in grain refining were analyzed. Based on the experimental conditions/parameters, it was found that the amount of impurities and the associated porosity were significantly reduced in USV treated alloys. Furthermore, USV reduced the time needed for dissolving the alloying element Cu, nevertheless, the best dissolving of Cu in this study was not possible without introducing further holding time. As a result of using a titanium-based sonotrode, a noticeable content of Ti was found in the ultrasonically treated alloys due to sonotrode erosion under USV. The dispersion of TiAl3 promoted, as a main factor, a grain refining effect at relatively constant and high melt temperature, other possible mechanisms of grain refining have been discussed.

Al-Cu Alloy Films Characterization and Studies Using TOF-SIMS, XPS, AFM, EBSD and TEM

2014 ◽  
Author(s):  
J.J. Shao ◽  
Y.Q. Shen ◽  
Y. Shen ◽  
Y.K. Zhou ◽  
K. Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Failure Analysis ◽  
Copper Alloys ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Cu Alloy ◽  
Tof Sims ◽  
Aluminum Copper Alloys ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Aluminum-copper alloys are popular for many applications that take advantage of the combination of properties in the alloys. This paper describes the use of multiple advanced failure analysis tools to analyze the physical and chemical properties of Al-Cu alloy thin films.

Surfaces Modification of Al-Cu Alloys by Plasma-Assisted CVD

2013 ◽  
Vol 199 ◽  
pp. 496-501 ◽  
Author(s):  
Karol Kyzioł ◽  
Łukasz Kaczmarek ◽  
Stanisława Jonas
Keyword(s):  
Wear Resistance ◽  
Copper Alloys ◽  
Chemical Vapour ◽  
Argon Plasma ◽  
High Strength ◽  
Aviation Industry ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Aluminum Copper Alloys ◽  
Pre Treatment

Aluminum-copper alloys (Al-Cu) are nowadays widely used in various applications, mainly in automotive and aviation industry, because of their unique properties such as high strength, low density and good corrosion resistance. However, usages of aluminum alloys are partially limited due to their reduced hardness, wear resistance and poor tribological parameters. Desired useful parameters can be improved by application of PA CVD technology. This work presents the results concerning determination and analysis of the structure and the selected properties of the modified surfaces of Al-Cu alloys (2xxx series) that were prepared using plasma assisted MW CVD (Micro-Wave Chemical Vapour Deposition) method. To ensure effectiveness of the substrate modification process, the covered surface was subjected to pre-treatment with argon plasma and/or nitriding process. In conclusion, the research has confirmed that the wear resistance of the Al-Cu alloy can be successfully modified by application of MW CVD technique. The obtained results can serve as a basis in the design of the technology of a-Si:C:N:H layers for diverse applications.

scholarly journals Effect of copper-enriched layers on localized corrosion of aluminium-copper alloys

2018 ◽  
Vol 27 (48) ◽  
Author(s):  
María Ángeles Arenas-Vara ◽  
Peter Skeldon ◽  
Sandra Judith García-Vergara
Keyword(s):  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Copper Alloys ◽  
Localized Corrosion ◽  
Pitting Potential ◽  
Cu Alloy ◽  
Aluminum Copper Alloys ◽  
Aluminium Copper ◽  
Sputter Deposited ◽  
Effect Of Copper

Copper-enriched layers were developed onto aluminum-copper alloys using alkaline etching in sodium hydroxide, for both, sputter deposited and bulk conditions. Enriched alloys were evaluated by potentiodynamic polarization in sodium chloride solution in order to determine the effect of the enriched layers on the pitting potential of the alloys. Rutherford backscattering spectroscopy was employed to quantify the enrichments and their locations just beneath the alumina-based oxides remaining from the etching. For the sputter deposited aluminum-copper alloys, the results show some scattering of the pitting potential data, and no correlation between pitting potential and the alloy enriched layer. In the case of bulk Al-2wt.%Cu alloy, with the copper in solid-solution, the pitting potential increased for the enriched specimens, indicating also a different pit morphology, with respect to the non-enriched alloy.

scholarly journals Numerical investigation of mechanical properties of aluminum-copper alloys at nanoscale

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Satyajit Mojumder ◽  
Md Shajedul Hoque Thakur ◽  
Mahmudul Islam ◽  
Monon Mahboob ◽  
Mohammad Motalab
Keyword(s):  
Mechanical Properties ◽  
Numerical Investigation ◽  
Copper Alloys ◽  
Aluminum Copper Alloys

Intercalation Processes in Cobalt Substituted Nickel Oxyhydroxides

1990 ◽  
Vol 210 ◽  
Author(s):  
Claude Delmas
Keyword(s):  
Ir Spectroscopy ◽  
Mechanical Treatment ◽  
Positive Charge ◽  
Van Der Waals ◽  
The Other ◽  
Hydrolysis Reaction ◽  
Water Molecules ◽  
Layered Oxides ◽  
Experimental Conditions ◽  
Cobalt Ions

AbstractChimie douce reactions (hydrolysis and reduction) from layered oxides : NaNiO2, NaxCoO2 and NaNil-xCoxO2 lead to numerous oxyhydroxides and hydroxides which differ by the composition of the intersheet space.According to the experimental conditions of the hydrolysis reaction, the oxyhydroxides can be unhydrated or intercalated with one or two layers of water molecules. From the most hydrated phases, the other ones can be obtained by chemical, thermal and even mechanical treatment.The reduction of Co-substituted nickel oxyhydroxides leads to hydroxides in which nickel and cobalt ions are respectively divalent and trivalent. In order to compensate the excess of positive charge in the (Ni, Co)O2 sheet, anions (OH-, CO32-, SO42-, NO3-) are inserted in the Van der Waals gap.For the highest anion amounts, well ordered α*-type materials are obtained. Water molecules are simultaneously inserted in the interslab space. Their structure is strongly related to the hydrotalcite one. When the amouit of anions in the intersheet space is not sufficient, interstratified materials are obtained. In this case the (Ni,Co)(OH)2 slabs are separated by a layer of CO32- anions and water molecules (α*-type) or by an empty Van der Waals gap (β(II)-type). The amount of α*-type planes in the structure increases with the cobalt amount. All these materials have been characterized by IR spectroscopy which allows to detect the existence of two types of O-H bonds (free in α*-type plane or hydrogen bonded in ²(II)-type plane).

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