Change search
Refine search result
1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Awe, Samuel A.
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Jarfors, Anders E. W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Development of cast Al-Cu-Si ternary eutectic alloys for high temperature applications2016In: Proceedings and Abstracts Book of European Advanced Materials Congress, At Stockholm, Sweden / [ed] Ashutosh Tiwari, Linköping: VBRI Press , 2016Conference paper (Refereed)
    Download full text (pdf)
    Abstract
  • 2.
    Bjurenstedt, Anton
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Casari, Daniele
    Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Mathiesen, Ragnvald H.
    Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway.
    Dahle, Arne K.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    In-situ study of morphology and growth of primary α-Al(FeMnCr)Si intermetallics in an Al-Si alloy2017In: Acta Materialia, ISSN 1359-6454, E-ISSN 1873-2453, Vol. 130, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Morphology and growth of primary α-Al(FeMnCr)Si intermetallics have been studied in-situ during solidification of a commercial secondary aluminum alloy employing X-radiographic imaging combined with deep-etching. The α-Al(FeMnCr)Si intermetallics were found to nucleate primarily on surface oxides, and the continued growth yielded both rhombic dodecahedrons and elongated rod-like morphologies. Both morphologies were observed as hopper and massive types, where the hopper intermetallics had the higher growth rates. The growth rate, which determines the type, appears to be linked to nucleation frequency; higher nucleation frequency promoted massive types and lower nucleation frequency promoted hopper intermetallics. 

  • 3.
    Bjurenstedt, Anton
    et al.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Ghassemali, Ehsan
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting. Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    The effect of Fe-rich intermetallics on crack initiation in cast aluminium: an in-situ tensile study2019In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 756, p. 502-507Article in journal (Refereed)
    Abstract [en]

    To evaluate the role of Fe-rich intermetallics on crack initiation, two fully modified Al-Si alloys, one containing plate-like β-Fe and the second containing primary α-Fe intermetallics, were investigated by in-situ tensile testing in the scanning electron microscope. In the first alloy, large plate-like β-Fe intermetallics oriented parallel to the test direction were the first to crack at an elongation of about 1.8%. More transversely oriented intermetallics caused crack initiation in the matrix which linked up with the final fracture. In the second alloy, the cracking of α-Fe intermetallics initiated at an elongation of about 0.9%. It is concluded that large α-Fe intermetallics crack first and that clusters of α-Fe are the most potent crack initiation sites.

  • 4.
    Bogdanoff, Toni
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne K.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy2018In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 12, no 3, p. 434-440Article in journal (Refereed)
    Abstract [en]

    Increasing environmental demands are forcing the automotive industry to reduce vehicle emissions by producing more light-weight and fuel efficient vehicles. Al–Si alloys are commonly used in automotive applications because of excellent castability, high thermal conductivity, good wear properties and high strength-to-weight ratio. However, most of the aluminium alloys on the market exhibit significantly reduced strength at temperatures above 200 °C. This paper presents results of a study of the effects of Co and Ni in a hypoeutectic Al–Si alloy on microstructure and mechanical properties at room and elevated temperature. Tensile test specimens with microstructures comparable to those obtained in high-pressure die casting, i.e. SDAS ~ 10 µm, were produced by directional solidification in a Bridgman furnace. The results show an improvement in tensile properties up to 230 °C.

    Download full text (pdf)
    Fulltext
  • 5.
    Bogdanoff, Toni
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Seifeddine, Salem
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Dahle, Arne K.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    The effect of SI content on microstructure and mechanical properties of Al-Si alloy2016In: La Metallurgia Italiana, ISSN 0026-0843, Vol. 108, no 6Article in journal (Refereed)
    Abstract [en]

    Al-Si alloys are the most popular casting alloys due to their excellent castability combined with high strengthto-weight ratio. This paper investigates the role of Si content in the range of 6.5 wt. % to 14.4 wt. % on the microstructure and mechanical properties of Al-Si-Mg casting alloys. All alloys were modified with 90-150 ppm Sr. No grain refiner was added. The samples were produced by directional solidification providing a microstructure that corresponds to microstructures found in die castings. From the phase diagram and coupled zone, increasing the Si level up to 14.4 wt. % is expected to start a competition between formation of α- dendrites and a fully eutectic microstructure. However, it is known that Sr-modification shifts the eutectic to higher Si contents. For the lower Si contents, the microstructure of the samples consisted of α-dendrites and a modified Al-Si eutectic. At 12.4 wt. % Si and above, a cellular eutectic microstructure was observed. No primary Si was observed even at 14.4 wt. % Si. The mechanical properties in terms of yield and tensile strength did not vary remarkably as a function of the Si level unlike the elongation to failure that dropped from 12 % at 6.5 wt. % Si to nearly 6 % at 14.4 wt. % Si; but still the material is exhibiting an elongation to failure that is far higher than normally expected.

    Download full text (pdf)
    fulltext
  • 6.
    Ceschini, Lorella
    et al.
    Department of Industrial Engineering (DIN), Alma Mater Studiorum–University of Bologna, Bologna, Italy.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Gupta, Manoj
    Department of Mechanical Engineering, National University of Singapore, Singapore.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jayalakshmi, S.
    Department of Mechanical Engineering, Bannari Amman Institute of Technology (BIT), Sathyamangalam, India.
    Morri, Alessandro
    Interdepartmental Center for Industrial Research-Advanced Mechanics and Materials (CIRI-MAM), Alma Mater Studiorum–University of Bologna, Bologna, Italy.
    Rotundo, Fabio
    Interdepartmental Center for Industrial Research-Advanced Mechanics and Materials (CIRI-MAM), Alma Mater Studiorum–University of Bologna, Bologna, Italy.
    Toschi, Stefania
    Department of Industrial Engineering (DIN), Alma Mater Studiorum–University of Bologna, Bologna, Italy.
    Singh, R. Arvind
    Department of Aeronautical Engineering, Bannari Amman Institute of Technology (BIT), Sathyamangalam, India.
    Aluminum and Magnesium Metal Matrix Nanocomposites2017Book (Other academic)
    Abstract [en]

    The book looks into the recent advances in the ex-situ production routes and properties of aluminum and magnesium based metal matrix nanocomposites (MMNCs), produced either by liquid or semi-solid state methods. It comprehensively summarizes work done in the last 10 years including the mechanical properties of different matrix/nanoreinforcement systems. The book also addresses future research direction, steps taken and missing developments to achieve the full industrial exploitation of such composites. The content of the book appeals to researchers and industrial practitioners in the area of materials development for metal matrix nanocomposites and its applications.

  • 7.
    Hernando, Juan Carlos
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Elfsberg, Jessica
    Scania CV AB, Södertälje, Sweden.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Evolution of primary austenite during coarsening and impact on eutectic microstructure in Fe–C–Si alloys2019In: Materialia, E-ISSN 2589-1529, Vol. 7, article id 100391Article in journal (Refereed)
    Abstract [en]

    The evolution of primary austenite morphology during isothermal coarsening has been studied in the three main Fe–C–Si alloys used in industry, LGI, CGI, and SGI. The dendritic microstructure increases length scale during coarsening accompanied by fragmentation and coalescence of austenite crystals. The morphological parameters, SDAS, Mγ, DhydID, and Dγ show a linear relation with the cube root of coarsening time, t1/3, with similar rates for the three different Fe–C–Si alloys. The eutectic microstructures after coarsening of primary austenite in CGI and SGI alloys are not significantly affected by the surface area of primary austenite and the size of the interdendritic regions. Fraction, nodularity, shape distribution of graphite particles and the number of nodules and eutectic cells are similar when studied as a function of coarsening time. These results suggest that the nucleation frequency in CGI and SGI, and the growth of eutectic microstructures in CGI, are not significantly influenced by the morphology of primary austenite.

    Download full text (pdf)
    Fulltext
  • 8.
    Hernando, Juan Carlos
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Elfsberg, Jessica
    Scania CV AB, Södertälje, Sweden.
    Ghassemali, Ehsan
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    The effect of coarsening of primary austenite on the ultimate tensile strength of hypoeutectic compacted graphite Fe-C-Si alloys2019In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 168, p. 33-37Article in journal (Refereed)
    Abstract [en]

    The effect of primary austenite morphology on the ultimate tensile strength (UTS) of hypoeutectic compacted graphite Fe-C-Si alloys (CGI) is studied by isothermal coarsening experiments. Secondary dendrite arm spacing (SDAS) and the morphological characteristics related to the surface area of primary austenite, M γ and D ID Hyd , increase with the cube root of coarsening time. UTS decreases linearly with increasing coarseness of primary austenite. The eutectic and eutectoid microstructures are unaffected by the primary austenite morphology. These observations demonstrate the strong influence of primary austenite morphology on the mechanical properties of hypoeutectic CGI alloys.

    Download full text (pdf)
    Fulltext
  • 9.
    Hernando, Juan Carlos
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Elfsberg, Jessica
    Scania CV AB, Södertälje, Sweden.
    Ghassemali, Ehsan
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Diószegi, Attila
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    The role of primary austenite morphology in hypoeutectic compacted graphite iron alloys2020In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 14, no 3, p. 745-754Article in journal (Refereed)
    Abstract [en]

    This work investigates the role of primary austenite morphology on the eutectic and eutectoid microstructures and the ultimate tensile strength (UTS) in a hypoeutectic compacted graphite iron (CGI) alloy. The morphology of primary austenite is modified by isothermal coarsening experiments in which holding times up to 60 min are applied to the solid–liquid region after coherency. The cooling conditions for the subsequent eutectic and eutectoid reactions are similar. Miniaturized tensile tests are performed to evaluate the UTS. The morphological characteristics related to the surface area of primary austenite, the modulus of primary austenite, Mγ, and the hydraulic diameter of the interdendritic region, DHydID, increase with the cube root of coarsening time. The eutectic and eutectoid microstructures are not significantly affected by the morphology of primary austenite, thus indicating that the morphology of the interdendritic regions does not control the nucleation frequency and growth of eutectic cells or graphite. UTS decreases linearly with the increasing coarseness of primary austenite for similar eutectic and eutectoid microstructures, demonstrating the strong influence of primary austenite morphology on the UTS in hypoeutectic CGI alloys.

  • 10.
    Kim, B. J.
    et al.
    Energy Component & Material R&BD Group, Korea Institute of Industrial Technology, Busan, 46938, South Korea.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Park, Y. H.
    Department of Materials Science and Engineering, Pusan National University, Busan, 46241, South Korea.
    Lee, Y. C.
    Energy Component & Material R&BD Group, Korea Institute of Industrial Technology, Busan, 46938, South Korea.
    The effect of Sr additions on Al–Cu–Si ternary eutectic alloys for a high-ductility bimodal microstructure2022In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 833, article id 142547Article in journal (Refereed)
    Abstract [en]

    Al–Cu–Si ternary eutectic alloys with a bimodal eutectic structure exhibit a good combination of strength and plasticity owing to the multiscale hierarchical microstructure. Previous studies have reported that bimodal eutectic structures can be successfully prepared by rapid solidification at a cooling rate of greater than 102 °C/s. In the present study, a bimodal eutectic structure was successfully prepared at a cooling rate of less than 10 °C/s by adding a small amount of Sr to Al–Cu–Si ternary eutectic alloys. Additions of Sr led to a notable modification of the microstructure from a mixed eutectic structure to a bimodal eutectic structure. Samples with the bimodal eutectic structure showed greater hardness, strength, and elongation than samples with mixed eutectic structure. In particular, the elongation increased significantly from 6% to 28%. The additions of Sr changed the microstructure of the Al–Si phase from needles to globular shapes, which are finely dispersed all through the microstructure. These results indicate that the improved mechanical properties with the addition of Sr can mainly be attributed to the development of a multiscale hierarchical microstructure with fine eutectic cells.

  • 11.
    Liu, Z.
    et al.
    School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei 430070, China.
    Sun, J.
    School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei 430070, China.
    Yan, Z.
    State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
    Lin, Y.
    School of Materials Science and Engineering, Wuhan University of Technology, Wuhan, Hubei 430070, China.
    Liu, M.
    School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
    Roven, H. J.
    Department of Materials Science and Engineering, Norwegian University of Science and Technology, Trondheim, 7491, Norway.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Enhanced ductility and strength in a cast Al–Mg alloy with high Mg content2021In: Materials Science & Engineering: A, ISSN 0921-5093, E-ISSN 1873-4936, Vol. 806, article id 140806Article in journal (Refereed)
    Abstract [en]

    Cast Al–Mg alloys with high Mg content have attracted considerable interest as a result of exceptionally low mass density and enhanced Mg solid-solution strengthening effect. However, poor ductility in this class of cast Al–Mg alloys originating from the increased amount of brittle Al3Mg2 phase presents a challenge. This work aims to improve ductility of a cast Al-10 wt%Mg alloy by prolonging time and/or increasing temperature during solid-solution treatment, hence minimizing the amount of the Al3Mg2 phase. The amounts of Al3Mg2 decrease and the concentrations of solute Mg increase with prolonging time and/or increasing temperature, improving both ductility and strength. Solid-solution treatment at 425 °C for 9 h or at 438 °C for 3 h induces complete dissolution of the Al3Mg2 phase, achieving an average uniform elongation of ~27% accompanied by an average 0.2% offset yield strength of ~186 MPa. The mechanisms improving both ductility and strength are discussed. 

  • 12.
    Olofsson, Jakob
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Salomonsson, Kent
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Mathiesen, Ragnvald H.
    Department of Physics, Faculty of Natural Sciences, Norwegian University of Science and Technology, NTNU, Trondheim, Norway.
    Three-dimensional study of nodule clustering and heterogeneous strain localization for tailored material properties in ductile iron2019In: IOP Conference Series: Materials Science and Engineering, Institute of Physics (IOP), 2019, Vol. 529, no 1, article id 012078Conference paper (Refereed)
    Abstract [en]

    Tailored heterogeneous distributions of microstructural features enable extraordinary material performance in biological and physiological structures such as trees, the aortic arch, human teeth and dinosaur skulls. In ductile iron, a heterogeneous distribution in size and morphology of graphite nodules and variations of the fractions of ferrite and pearlite are created during solidification, and varies as a function of parameters such as local cooling rate, segregation and flow. In the current work, the size distribution as well as the orientation and relation between graphite nodules is obtained by a three-dimensional reconstruction of a ductile iron microstructure from X-ray tomography. The effect of the nodule morphology and clustering on the localization of plastic strains is studied numerically using finite element analysis of the reconstructed microstructure. Real castings have a variation in geometry, solidification conditions and are subjected to variations in loads. A framework for optimized geometry and solidification conditions in order to design and deliver castings with tailored local material performance is proposed.

  • 13.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne K.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Magnesium solubility in primary α-al and heat treatment response of cast Al-7Si-Mg2020In: Metals, ISSN 2075-4701, Vol. 10, no 5, article id 614Article in journal (Refereed)
    Abstract [en]

    Magnesium and silicon concentrations in the interior of primary α-Al of Al-7Si-Mg alloys were studied at temperatures in the liquid-solid range and just after solidification was completed. Analysis of the results showed that the magnesium concentration in the interior of primary α-Al is very low in the temperatures range from the liquidus to the start of the Al-Si eutectic reaction. Formation of silicon-rich phases during eutectic reactions, such as eutectic silicon and β-Al5FeSi, phases trigger a significant increase in the magnesium concentration in the interior of primary α-Al, when sufficient time is allowed for solid-state diffusion to occur. When fast cooling rates are applied during the Al-Si eutectic reaction, most of the magnesium is retained in π-Al8FeMg3Si6 and Mg2Si phases formed during solidification. Semi-solid Al-7Si-Mg castings were produced with varying magnesium contents, and the mechanical properties were evaluated in the as-cast, T5 and T6 conditions. It was found that the 0.2% offset yield strength of the semi-solid Al-7Si-Mg castings in the T5 and T6 conditions increases linearly with the square root of the magnesium concentration in the interior of the α-Al globules formed during the slurry preparation process. 

  • 14.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E. W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Tag-and-Trace Method of α-Al Crystals Applied to Study Solidification and Casting of Aluminum Alloys2022In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 53, p. 3311-3320Article in journal (Refereed)
    Abstract [en]

    In this study, a new tag-and-trace method of α-Al crystals was developed and used to study the dissolution of a rotating Al-3Si-0.15Ti cylinder immersed into a superheated commercial purity aluminum melt. The developed tag-and-trace method consists of tagging the primary crystals of an alloy with the microsegregation of a peritectic forming solute element, e.g., titanium in aluminum alloys. During solidification, the primary crystals form with a high concentration of the peritectic forming solute, decreasing in the adjacent growth regions of the same crystal. After solidification, the solute microsegregation tag in the interior of the primary crystals can be revealed by color etching. In this work, an Al-3Si-0.15Ti cylinder with all the primary α-Al crystals tagged with titanium was immersed into a superheated titanium-free aluminum alloy. The superheat was varied, and all samples were quenched 10s after immersion of the cylinder. The tagged α-Al crystals from the original cylinder could be distinguished from the non-tagged α-Al crystals formed in the thermally undercooled region surrounding the cylinder and during quenching. Indications of liquid penetration were observed in some α-Al crystals, which indicates that disintegration of α-Al crystals may occur during stirring of the alloy cylinder into a superheated alloy.

  • 15.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Fatigue crack initiation in semi-solid Al-7Si-Mg castingsManuscript (preprint) (Other academic)
  • 16.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Filling, Feeding and Defect Formation of Thick-Walled AlSi7Mg0.3 Semi-Solid Castings2016In: Solid State Phenomena, ISSN 1012-0394, E-ISSN 1662-9779, Vol. 256, p. 222-227Article in journal (Refereed)
    Abstract [en]

    Aluminium semi-solid castings have gained increased attention due to their superior mechanical properties, lower porosity compared to conventional high pressure die cast material. These characteristics suggests that semi-solid casting should be suitable to produce thick-walled structural components, yet most successful applications of semisolid casting have been for thin-walled components. There is a lack of understanding on filling and feeding related defect formation for semi-solid castings with thick-walled cross-sections. In the current study an AlSi7Mg0.3 aluminium alloy was used to produce semi-solid castings with a wall thickness of 10mm using a Vertical High Pressure Die Casting machine. The RheoMetalTM process was used for slurry preparation. The primary solid α-Al fraction in the slurry was varied together with die temperature. The evaluation of the filling related events was made through interrupted shots, stopping the plunger at different positions. Microscopy of full castings and interrupted test samples were performed identifying the presence of surface segregation layer, shear bands, gas entrapment, shrinkage porosity as well as burst feeding.

    Download full text (pdf)
    Fulltext
  • 17.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Formation of coarse silicon near the surface of Al-7Si-Mg semi-solid castings2021In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 52, p. 5140-5145Article in journal (Refereed)
    Abstract [en]

    Primary type polyhedral silicon crystals were observed in the vicinity of oxides located at or near the surface of strontium modified semi-solid Al–7Si–Mg castings. The coarse silicon polyhedrons were observed mainly on the outer side of oxides surrounding the macrosegregation regions. The silicon crystals most likely nucleated on AlP-particles located near the oxides. These AlP particles may nucleate on the wetted surface of oxides, or form at different locations in the interdendritic regions.

  • 18.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Formation of Iron-Rich Intermetallic Phases in Al-7Si-Mg: Influence of Cooling Rate and Strontium Modification2019In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 50, no 9, p. 4148-4165Article in journal (Refereed)
    Abstract [en]

    The influence of cooling rate on the formation of iron-rich intermetallic phases during solidification of unmodified and strontium-modified Al-7Si-0.3Mg alloys has been investigated. The effect of strontium on the intermetallic phases was evaluated in unquenched and quenched samples. Samples were quenched before the start of the Al-Si eutectic reaction, along the Al-Si eutectic reaction and just after the end of solidification. The results show that the addition of strontium increased the size of both β-Al5FeSi and π-Al8FeMg3Si6 at low cooling rates. For unmodified and strontium-modified alloys, an increase of cooling rate resulted in a decrease in size of the intermetallic phases, particularly in the strontium modified alloy. In the strontium modified alloy quenched before the start of the Al-Si eutectic reaction, π-Al8FeMg3Si6 appeared as thin platelets at the eutectic cell boundaries. Chinese script-like π-Al8FeMg3Si6 and platelet-like β-Al5FeSi intermetallic phases were observed uniformly distributed in the eutectic regions in the unmodified alloy quenched before the start of the eutectic reaction. Strontium modified semi-solid Al-7Si-0.3Mg castings were produced and the type of intermetallic phase, morphology, size, area fraction and distribution were similar to that observed in the strontium modified alloy quenched before the start of the Al-Si eutectic reaction.

  • 19.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Tag-and-trace method of α-Al crystals to study the dissolution of an aluminium alloyManuscript (preprint) (Other academic)
  • 20.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing. Jönköping University, School of Engineering, JTH. Research area Materials and manufacturing – Casting.
    The effect of magnesium on the intermetallic phases and heat treatment response of cast Al‐7Si‐MgManuscript (preprint) (Other academic)
  • 21.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Variation of properties in the cross-section of semi-solid al-7si-0.3mg castings2019In: Semi-Solid of Alloys and Composites / [ed] Rassili A.,Midson S.P.,Zhu Q.,Gang Hu X., Trans Tech Publications, 2019, p. 81-86Conference paper (Refereed)
    Abstract [en]

    In semi-solid casting, a slurry consisting of primary α-Al crystals and liquid is injected into the die cavity. The solidification in the die-cavity occurs by the growth of the primary α-Al crystals formed during slurry preparation and in the shot sleeve, nucleation and growth of in-cavity solidified crystals and ends with the eutectic reaction. During solidification in the die cavity, the cooling rate near the die wall is higher in comparison to the centre of the casting, particularly for thick-walled castings. The solidification conditions for the slurry α-Al crystals that are closer to the die wall can be very different compared to the slurry α-Al crystals located at the casting centre. This can result in different solute concentration in the interior of the α-Al globules in different regions of the semi-solid casting cross-section and consequently, different response to heat treatament. The RheoMetal™ process was used to produce thick-walled semi-solid castings. Semi-solid castings in the as-cast and T6 conditions were investigated. Indentation tests for hardness measurements in the nano-range were performed in the interior of α-Al globules near the surface and at the casting cross-section centre. The hardness variation across the casting cross-section was evaluated by low-force Vickers hardness. The castings in the as-cast condition showed more uniform properties in the cross-section compared to the T6 condition. Additionally, the results suggest that microsegregation in the interior of α-Al globules is very low in castings in the as-cast and T6 conditions. 

  • 22.
    Santos, Jorge
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Kallien, Lothar H.
    Department of Applied Sciences, Aalen University, Aalen, Germany.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Influence of grain refinement on slurry formation and surface segregation in semi-solid Al-7Si-0.3Mg castings2018In: Metallurgical and Materials Transactions. A, ISSN 1073-5623, E-ISSN 1543-1940, Vol. 49A, no 10, p. 4871-4883Article in journal (Refereed)
    Abstract [en]

    This study aims to evaluate the effect of grain refinement on slurry formation and surface segregation in semi-solid castings produced by the Rheometal™ process. The effect of two grain refiners, Al-8B and Al-5Ti-1B, on the slurry α-Al grain size, shape factor and solid fraction was evaluated. The results suggest that the addition of a grain refiner can affect the solid fraction obtained in the RheometalTM process and, consequently, reduce the solute content near the casting surface. Grain refiner addition resulted in a larger fraction of α-Al grains ≤ 60 µm for the refined alloys compared with the unrefined alloy. Additionally, the growth of α-Al slurry globules was greater for the unrefined alloy compared with the refined alloy during solidification in the die-cavity. A more homogeneous and finer microstructure was observed near the surface in the grain-refined castings compared with the unrefined castings. Evidence of significant liquid penetration was identified in some α-Al globules, indicating that disintegration of α-Al globules may occur during the Rheometal™ casting process.

  • 23.
    Zhang, Qing
    et al.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jonsson, S.
    Royal Institute of Technology, Department of Materials science, Stockholm, 1044, Sweden.
    Dahle, Arne
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Jarfors, Anders E.W.
    Jönköping University, School of Engineering, JTH, Materials and Manufacturing.
    Role of Iron-Rich Phases and Porosity on the Ductility of Rheocast Al-Mg-Si-Alloys2022In: Solid State Phenomena / [ed] J. Li & A. Rassili, Trans Tech Publications, 2022, Vol. 327, p. 65-70Chapter in book (Refereed)
    Abstract [en]

    Treatment of the slurry is important during RheoMetalTM casting. In this work, semi-solid slurries were prepared under different stirring intensities, using two types of stirrers: a naked rod (for regular stirring) and a rod with two blades (for intensive stirring). Tensile tests were performed, investigating fracture surfaces, as well as metallographic samples. The results show that intensive stirring produces castings with finer primary particles and a more homogeneous microstructure. On the other hand, more faceted Fe-rich phases are found along the α-Al grains boundary, due to the dissolution of Fe from the stirrers. Moreover, for intensive stirring castings, the porosity found on the fracture surfaces are smaller, while more second (intermetallic) phases, especially Fe-rich phases, are observed. Consequently, the castings with intensive stirring show worse ductility. Finally, a quantitative analysis was made regarding ductility, affected both by porosity and the presence of Fe-rich phases.

1 - 23 of 23
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf