| 1. |
- Jaradeh, Majed, et al.
(författare)
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Analysis of solidification in a Bridgman furnace as a simulation of DC casting of aluminium alloy slabs
- 2007
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Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 23:4, s. 475-482
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Tidskriftsartikel (refereegranskat)abstract
- The vertical Bridgman directional solidification equipment has been used in several investigations to simulate direct chill casting of wrought aluminium alloys. As a basis for such investigations and alloy developments, it is important to have an understanding of the performance of the furnace used during simulation of the casting conditions. In this investigation the thermal conditions in the furnace have been analysed in detail, both by measurements and by mathematical modelling. The growth characteristics of the furnace, such as gradient, growth rates and cooling rates have been compared to conditions in large ingots. The direct chill casting conditions, which the simulations have been compared to, are casting of slabs of 330 and 600 mm thickness of an aluminium AA3003 type alloy. The results show that the experiments are able to simulate the cooling conditions in the ingots except from the surface zone. Comparisons of the microstructures have been made and a good agreement has been obtained for structure parameters such as grain size and DAS.
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| 2. |
- Jaradeh, Majed, et al.
(författare)
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Differential thermal analysis and differential scanning calorimetry studies of aluminum 3003 alloys with Zn and Cu additions
- 2007
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Ingår i: Metallurgical and Materials Transactions. A. - : Springer Science and Business Media LLC. - 1073-5623 .- 1543-1940. ; 38:9, s. 2138-2147
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Tidskriftsartikel (refereegranskat)abstract
- The effect of Zn additions in the range of 0 to 5 wt pct and Cu contents of 0.15 to 1.0 wt pct on the solidification and precipitation behavior of aluminum alloys of AA 3003 type was investigated with differential thermal analysis (DTA), differential scanning calorimetry (DSC), optical microscopy, and scanning electron microscopy/energy-dispersive X-ray (SEM/EDX). The results show that the additions of varying Zn and Cu have significant effects on the crystallization process, phase precipitation, and microstructure formation of the alloys. Phases formed have been identified and morphological differences have been discussed
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| 3. |
- Jaradeh, Majed, et al.
(författare)
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Directional solidification of type AA3003 alloys with addition of Zn and Si
- 2004
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Ingår i: SOLIDIFICATION OF ALUMINUM ALLOYS. - 0873395697 ; , s. 53-62
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Konferensbidrag (refereegranskat)abstract
- Directional solidification has been used to study effects on the structure and on materials properties from variations in the alloy contents in type AA 3003 alloys, Structure parameters such as grain size, DAS and secondary phase precipitations have been evaluated, as well as micro segregation, micro hardness and coarsening after solidification. Here the first part of the project is reported, and additions of Zn and Si have been studied. Zn additions improve the strength of the matrix of the material through solid solution hardening. At a level of 5% the hardness is improved by about 50%, but the solidification structure becomes less promising. The DAS and the secondary phases become coarse, and the solidification range increases significantly as the Zn content increases from 2.5 to 5%. Additions of Si, which have a significantly lower solubility than Zn, quickly gives larger amounts of secondary phase precipitations and a longer solidification interval.
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| 4. |
- Jaradeh, Majed, et al.
(författare)
-
Directional Solidification of Type AA3003 Alloys with Additions of Zn and Si
- 2004
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Ingår i: SOLIDIFICATION OF ALUMINUM ALLOYS. - : MINERALS, METALS & MATERIALS SOC. - 0873395697 ; , s. 53-62
-
Konferensbidrag (refereegranskat)abstract
- Directional solidification has been used to study effects on the structure and on materials properties from variations in the alloy contents in type AA 3003 alloys, Structure parameters such as grain size, DAS and secondary phase precipitations have been evaluated, as well as micro segregation, micro hardness and coarsening after solidification.Here the first part of the project is reported, and additions of Zn and Si have been studied. Zn additions improve the strength of the matrix of the material through solid solution hardening. At a level of 5% the hardness is improved by about 50%, but the solidification structure becomes less promising. The DAS and the secondary phases become coarse, and the solidification range increases significantly as the Zn content increases from 2.5 to 5%.Additions of Si, which have a significantly lower solubility than Zn, quickly gives larger amounts of secondary phase precipitations and a longer solidification interval.Directional Solidification of Type AA3003 Alloys with Additions of Zn and Si.
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| 5. |
- Jaradeh, Majed, et al.
(författare)
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DTA and DSC Studies of Aluminium 3003 Alloys with Zn and Cu Additions
- 2007
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Ingår i: Metallurgical and Materials Transactions. A. - New York : Springer. - 1073-5623 .- 1543-1940. ; 38A, s. 2138-2147
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Tidskriftsartikel (refereegranskat)abstract
- The effect of Zn additions in the range of 0-5wt.% and Cu contents of 0.15-1.0 wt.%, on the solidification and precipitation behaviour of aluminium alloys of AA 3003 type was investigated with differential thermal analysis (DTA), differential scanning calorimetry (DSC), optical microscopy (OM), and scanning electron microscopy (SEM/EDX). The results show that the additions of varying Zn and Cu have significant effects on the crystallization process, phase precipitation and microstructure formation of the alloys. Phases formed have been identified and morphological differences have been discussed.
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| 6. |
- Jaradeh, Majed, et al.
(författare)
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Effect of refiner addition level on zirconium-containing aluminium alloys
- 2012
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Ingår i: IOP Conference Series: Materials Science and Engineering. - : Institute of Physics (IOP). ; , s. Art. no. 012008-
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Konferensbidrag (refereegranskat)abstract
- It is well known that in aluminium alloys containing Zr, grain refiner additions do not function as desired, producing an effect often referred to as nuclei poisoning. This paper investigates the structure of direct chill-cast ingots of commercial AA3003 aluminium alloys, with and without Zr, at various addition levels of Al5Ti1B master alloy. In Bridgman experiments simulating ingot solidification, Zr-containing alloys were studied after the addition of various amounts of Ti. It could be demonstrated, in both ingot casting and simulation experiments, that Zr poisoning can be compensated for by adding more Ti and/or Al5Ti1B. The results confirm better refinement behaviour with the addition of Ti + B than of only Ti. The various combinations of Zr and Ti also influenced the formation of AlFeMn phases, and the precipitation of large Al 6(Mn,Fe) particles was revealed. AlZrTiSi intermetallic compounds were also detected.
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| 7. |
- Jaradeh, Majed, et al.
(författare)
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Effect of titanium additions on the microstructure of DC-cast aluminium alloys
- 2005
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Ingår i: Materials Science and Engineering A. - : Elsevier BV. - 0921-5093. ; 413-414, s. 277-282
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Tidskriftsartikel (refereegranskat)abstract
- The effect of the Ti content on the solidification structures of aluminum alloys of AA3003 type was investigated. Some improved corrosion properties can be obtained from increasing the Ti contents in aluminium alloys to a level above the normal practice for grain refinement. However, increasing the Ti content above the peritectic point, 0.15%, can influence the grain refinement and cause casting difficulties. The investigation was made by both characterizing the grain structure over the width of DC-cast rolling ingots of different alloys, and by studying the solidification microstructure of Bridgman directional solidified samples, grown to simulate ingot solidification. Structure properties such as grain size, distances between secondary phases and microstructure coarsening were studied. It was found that with normal Ti contents in the range of 0.015%, the grain refinement is effective. However, upon larger Ti additions to levels around 0.15% the grain structure becomes coarser.
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| 8. |
- Jaradeh, Majed, et al.
(författare)
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Effect of titanium on the microstructure of DC-cast aluminium alloys
- 2005
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Ingår i: Materials Science & Engineering. - : Elsevier BV. - 0921-5093 .- 1873-4936. ; 413, s. 277-282
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Tidskriftsartikel (refereegranskat)abstract
- The effect of the Ti content on the solidification structures of aluminum alloys of AA3003 type was investigated. Some improved corrosion properties can be obtained from increasing the Ti contents in aluminium alloys to a level above the normal practice for grain refinement. However, increasing the Ti content above the peritectic point, 0,15%, can influence the grain refinement and cause casting difficulties. The investigation was made by both characterizing the grain structure over the width of DC cast rolling ingots of different alloys, and by studying the solidification micro-structure of Bridgman directional solidified samples, grown to simulate ingot solidi-fication. Structure properties such as grain size, distances between secondary phases and microstructure coarsening were studied. The hardness of the alloys was also determined. It was found that with normal Ti contents in the range of 0,015% the grain refinement is effective. However, upon larger Ti additions to levels around 0,15% the grain structure becomes coarser.
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| 9. |
- Jaradeh, Majed M., et al.
(författare)
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Analysis of Distribution of Nonmetallic Inclusions in Aluminum DC-Cast Billets and Slabs
- 2012
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Ingår i: Metallurgical and materials transactions. B, process metallurgy and materials processing science. - : Springer Science and Business Media LLC. - 1073-5615 .- 1543-1916. ; 43:1, s. 82-91
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Forskningsöversikt (refereegranskat)abstract
- Inclusion distribution was studied in commercial aluminum DC-cast billets and slabs using a newly developed deep-etching method. Analyses revealed a nonuniform distribution of nonmetallic inclusions across billet diameters and lengths, and also across slab thicknesses and widths. In as-cast billets, more inclusions were found at the beginning and end of the billet length; more were present near the cross-section center than near the surface. In slabs, inclusions were located mostly within 13 mm of the surface and in a band between the centerline and the surface. Few inclusions were found 60 to 100 mm from the slab surface or at the centerline. In addition, comparing slab quality after casting using three types of ceramic foam filters (CFFs; i.e., 30 ppi, 50 ppi, and 50 ppi + HF) revealed significant differences in inclusion size, number, and distribution. Casting slabs using a finer pore-size filter (50 ppi) reduced the number of non-metallic inclusions greatly. The inclusion distribution patterns observed in the solidified slabs are discussed in terms of melt flow during casting.
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| 10. |
- Jaradeh, Majed M. R., et al.
(författare)
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Solidification Studies of 3003 Aluminium Alloys with Cu and Zr Additions
- 2011
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Ingår i: Journal of Materials Science & Technology. - 1005-0302. ; 27:7, s. 615-627
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Tidskriftsartikel (refereegranskat)abstract
- The effects of Cu and Zr additions, on the microstructure formation, precipitation and ingot cracking, in commercial 3003 Al alloys have been studied. The investigation was carried out by characterizing the grain structure in DC-cast rolling ingots, and studying the solidification microstructure of Bridgman directionally solidified samples. To better understand the influence of the different Cu and Zr contents on the phase precipitations, differential thermal analysis (DTA) experiments were performed. Results from the ingot microstructure analysis show that in commercial alloys with relatively high contents of Cu and Zr, no significant differences in measured grain sizes compared to conventional 3003 Al alloys could be found. However, only Zr containing alloys exhibited significantly larger grain sizes. Increased grain refiner and/or titanium additions could compensate for the negative effects on nucleation normally following Zr alloying. Different types of precipitates were observed. Based on DTA experiments, increased Cu and Zr contents resulted in the formation of Al2Cu phase, and increased solidification range. It was also found that increased Mn content favors an early precipitation of Al(6)(Mn,Fe) giving relatively coarse precipitates. It was concluded that the Cu alloying has a detrimental effect on hot tearing.
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