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Bogdanoff, T., Ghassemali, E., Riestra, M. & Seifeddine, S. (2019). Prototyping of a high pressure die cast al-si alloy using plaster mold casting to replicate corresponding mechanical properties. In: Minerals, Metals and Materials Series: . Paper presented at Light Metals Symposium held at the TMS Annual Meeting and Exhibition, 2019, San Antonio, United States, 10 - 14 March 2019 (pp. 435-442). Springer
Open this publication in new window or tab >>Prototyping of a high pressure die cast al-si alloy using plaster mold casting to replicate corresponding mechanical properties
2019 (English)In: Minerals, Metals and Materials Series, Springer, 2019, p. 435-442Conference paper, Published paper (Refereed)
Abstract [en]

Prototyping prior high pressure die casting (HPDC) is used for product/mold design optimization. Plaster mold casting is a cost-efficient prototyping technique providing good surface quality and dimension accuracy, similar to HPDC components. However, the corresponding mechanical properties of a component produced with these two methods are diverging significantly, mainly due to differences in the cooling rate. This work presents a procedure to optimize the plaster mold casting for prototyping to replicate mechanical properties of a commonly used Al-Si alloy (A380). Two commercial alloys with compositions close to the A380 alloy (A356.0 and A360.2) were used. Yield strength was considered as the main design criteria, thus the target mechanical property. Tensile testing results showed that with an optimized T6 heat treatment, not only the yield strength, but also ultimate tensile strength and elongation correspond well to the properties in the HPDC component.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Aluminium alloys, Heat treatment, Prototyping, Aluminum alloys, Die casting, Light metals, Mechanical properties, Molds, Plaster, Product design, Software prototyping, Tensile strength, Tensile testing, Yield stress, Commercial alloys, Design criteria, Design optimization, Dimension accuracy, High pressure die casting, High pressure die casts, T6 heat treatment, Ultimate tensile strength, Silicon alloys
National Category
Materials Engineering
Identifiers
urn:nbn:se:hj:diva-43728 (URN)10.1007/978-3-030-05864-7_56 (DOI)2-s2.0-85064856753 (Scopus ID)9783030058630 (ISBN)9783030058647 (ISBN)
Conference
Light Metals Symposium held at the TMS Annual Meeting and Exhibition, 2019, San Antonio, United States, 10 - 14 March 2019
Available from: 2019-05-22 Created: 2019-05-22 Last updated: 2019-05-22Bibliographically approved
Riestra, M., Bjurenstedt, A., Bogdanoff, T. & Ghassemali, E. (2018). Complexities in the assessment of melt quality. Paper presented at Symposium on Light Metals Alliance - Light Metals Technology (LMT) held during the Conference on Materials Science and Technology (MS and T), October 8, 2017, Pittsburgh, PA, USA. International Journal of metalcasting, 12(3), 441-448
Open this publication in new window or tab >>Complexities in the assessment of melt quality
2018 (English)In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 12, no 3, p. 441-448Article in journal (Refereed) Published
Abstract [en]

If high-performance aluminium castings are to be produced, the melt quality needs to be properly assured. Multiple tests for melt quality assessment exist and have previously been analysed. In most studies, the techniques were used separately. In this work, reduced pressure, fluidity, Prefil and tensile tests were evaluated. A commercial EN 46000 alloy was used as the base material with additions of 25 and 50 wt% machining chips to degrade the melt quality. In reduced pressure and fluidity tests, oxides floated to the top of samples, decreasing the reliability. Bifilm index increased with addition level, but not correspondingly. Density index, Prefil and fluidity tests did not present significant variations, and tensile properties only deteriorated with the 50 wt% addition level. The investigated techniques provided information, but measuring the melt quality reliably remains a challenge.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
melt quality; reduced pressure test; fluidity; tensile properties; Prefil; hydrogen content
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38003 (URN)10.1007/s40962-017-0179-y (DOI)000436927100005 ()2-s2.0-85049321529 (Scopus ID)
Conference
Symposium on Light Metals Alliance - Light Metals Technology (LMT) held during the Conference on Materials Science and Technology (MS and T), October 8, 2017, Pittsburgh, PA, USA
Available from: 2017-11-28 Created: 2017-11-28 Last updated: 2019-02-14Bibliographically approved
Bogdanoff, T., Dahle, A. K. & Seifeddine, S. (2018). Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy. International Journal of metalcasting, 12(3), 434-440
Open this publication in new window or tab >>Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy
2018 (English)In: International Journal of metalcasting, ISSN 1939-5981, E-ISSN 2163-3193, Vol. 12, no 3, p. 434-440Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Springer, 2018
Keywords
Al–Si alloy, mechanical properties, cobalt, nickel, elevated temperature
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-37539 (URN)10.1007/s40962-017-0178-z (DOI)000436927100004 ()2-s2.0-85049356111 (Scopus ID)
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2019-02-05Bibliographically approved
Ghassemali, E., Riestra, M., Bogdanoff, T., Kumar, B. S. & Seifeddine, S. (2017). Hall-Petch Equation in a Hypoeutectic Al-Si Cast Alloy: Grain Size vs. Secondary Dendrite Arm Spacing. In: Procedia Engineering: . Paper presented at International Conference on the Technology of Plasticity, ICTP 2017; Hucisko; United Kingdom; 17 September 2017 through 22 September 2017 (pp. 19-24). Elsevier, 207
Open this publication in new window or tab >>Hall-Petch Equation in a Hypoeutectic Al-Si Cast Alloy: Grain Size vs. Secondary Dendrite Arm Spacing
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2017 (English)In: Procedia Engineering, Elsevier, 2017, Vol. 207, p. 19-24Conference paper, Published paper (Refereed)
Abstract [en]

The Al-Si cast alloy family is widely used in the production of complex castings for various applications and known for its very good castability and high strength-to-weight ratio. However, early cracking under tensile loading is sometimes a limiting factor. Among other parameters, it is yet controversial whether grain boundaries are dominant strengthening factor in cast alloys, instead of dendrite/eutectic boundaries. This study presents the effect of secondary dendrite arm spacing (SDAS) and grain size on crack initiation and propagation of Al-Si cast alloys under tensile loading. The Al-10Si (wt.%) alloy with modified Si morphology was cast using inoculants (Al-5Ti-B master alloy) under different cooling rates to obtain a range of grain sizes (from below 138 μm to above 300 μm) and SDAS (6, 15 and 35 μm). Conventional tensile test as well as in-situ tensile test in a scanning electron microscope, equipped with an electron backscatter diffraction (EBSD) was carried out to understand the deformation mechanisms of the alloy. Observation of slip bands within the dendrites showed that in modified Si structure, the interdendritic (eutectic) area takes more portion of the strain during plastic deformation. Besides, only a few cracks were initiated at the grain boundaries; they were mostly initiated from dendrite/eutectic interface. All cracks propagated trans-granularly. Hall-Petch calculations also showed a strong relationship between SDAS and flow stress of the cast alloy. Although statistically correct, there was no physically meaningful relationship between the grain size and the flow stress. Nevertheless, formation of identical slip bands in each grain could be an evidence for the marginal effect of the grain size on the overall strength development of the alloy. Consequently, among other effects, the combinational dominant effect of SDAS and modest effect of grain size shall be considered for modification of the Hall-Petch equation for precise prediction of mechanical properties of cast alloys.

Place, publisher, year, edition, pages
Elsevier, 2017
Series
Procedia Engineering, ISSN 1877-7058 ; 207
Keywords
Aluminum, Aluminum alloys, Aluminum compounds, Cracks, Grain boundaries, Grain size and shape, High strength alloys, Plastic flow, Plasticity, Scanning electron microscopy, Silicon, Tensile stress, Tensile testing, Titanium alloys, Titanium compounds, Cast alloys, Crack initiation and propagation, Cracking mechanisms, EBSD, Electron back scatter diffraction, Hall-petch, Prediction of mechanical properties, Secondary dendrite arm spacing, Silicon alloys
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38004 (URN)10.1016/j.proeng.2017.10.731 (DOI)XYZ ()2-s2.0-85036643961 (Scopus ID)
Conference
International Conference on the Technology of Plasticity, ICTP 2017; Hucisko; United Kingdom; 17 September 2017 through 22 September 2017
Available from: 2017-11-28 Created: 2017-11-28 Last updated: 2018-06-11Bibliographically approved
Ali, S., Bogdanoff, T., Seifeddine, S. & Jonson, B. (2017). Hardness, elastic modulus and refractive index of oxynitride glasses prepared from woody biofuel ashes. European Journal of Glass Science and Techology. Part B. Physics and Chemistry of Glasses, 58(6), 231-236
Open this publication in new window or tab >>Hardness, elastic modulus and refractive index of oxynitride glasses prepared from woody biofuel ashes
2017 (English)In: European Journal of Glass Science and Techology. Part B. Physics and Chemistry of Glasses, ISSN 1753-3562, Vol. 58, no 6, p. 231-236Article in journal (Refereed) Published
Abstract [en]

This paper reports the hardness, elastic modulus and refractive index values of the oxynitride glasses prepared from woody biofuel ashes. The glasses were prepared in nitrogen atmosphere at 1350-1500°C with addition of Ca metal as a precursor to the extra addition of this modifier. The glasses were homogenous, but appeared translucent grey to black. They contained up to 23 eq% of Ca and 5 eq% of N. The glass densities vary slightly between 2·76 to 2·92 g/cm3. The molar volume and compactness values vary between 8·01 cm3/mol to 8·31 cm3/mol and 0·446 to 0·462 respectively. Mechanical properties like hardness and reduced elastic modulus show values, up to 10 and 105 GPa, respectively. These properties are strongly correlated with the amount of N in the glass. The refractive index (1·54-1·75) increases with increasing N and Ca contents.

Place, publisher, year, edition, pages
Society of Glass Technology, 2017
Keywords
Biofuels, Calcium, Elastic moduli, Glass, Hardness, Nitrides, Biofuel ashes, Glass density, Nitrogen atmospheres, Oxynitride glass, Reduced elastic modulus, Refractive index
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-38297 (URN)10.13036/17533562.58.6.039 (DOI)000415784300001 ()2-s2.0-85033780200 (Scopus ID)JTHMaterialIS (Local ID)JTHMaterialIS (Archive number)JTHMaterialIS (OAI)
Available from: 2017-12-27 Created: 2017-12-27 Last updated: 2018-09-11Bibliographically approved
Riestra, M., Ghassemali, E., Bogdanoff, T. & Seifeddine, S. (2017). Interactive effects of grain refinement, eutectic modification and solidification rate on tensile properties of Al-10Si alloy. Journal of materials processing & manufacturing science (Print), 703, 270-279
Open this publication in new window or tab >>Interactive effects of grain refinement, eutectic modification and solidification rate on tensile properties of Al-10Si alloy
2017 (English)In: Journal of materials processing & manufacturing science (Print), ISSN 1062-0656, E-ISSN 1530-8065, Vol. 703, p. 270-279Article in journal (Refereed) Published
Abstract [en]

This study aims to clarify the effect of grain size and Si modification on the microstructure and tensile properties of the Al-10Si cast alloy, solidified under various cooling rates. To replicate the effect of cooling rate, directionally solidified samples were produced by remelting of the as-cast cylindrical bars. Tensile properties, grain sizes, Si modification level and chemical composition profiles were evaluated. Results showed that fast cooling rates alone, without the addition of grain refiners (Al-5Ti-1B master alloy), did not lead to equiaxed grain morphologies. On the other hand, for the slowest cooling rate tested, combined additions of the Al-5Ti-1B and the Al-10Sr master alloys resulted in equiaxed grain structures while addition of only grain refiner resulted in columnar grains. The combined additions effectively produced an equiaxed grain structure at all cooling rates tested, and further improved the tensile properties.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Directional solidification, Grain size, EBSD, Microstructure, Aluminium alloys, Casting
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-36814 (URN)10.1016/j.msea.2017.07.074 (DOI)000412034600031 ()2-s2.0-85026242378 (Scopus ID)
Available from: 2017-08-09 Created: 2017-08-09 Last updated: 2017-12-20Bibliographically approved
Jarfors, A., Matsushita, T., Bogdanoff, T., Börrisson, M. & Beste, U. (2016). Effect of Use in High Pressure Die Casting on Vibenite®60 Tool Inserts Madeby Additive Manufacturing. In: B. Müller (Ed.), DDMC2016 Frauenhofer Direct Digital Manufacturing Conference: Conference Proceedings, March 2016, Berlin, Germany. Paper presented at DDMC2016 Frauenhofer Direct Digital Manufacturing Conference. Fraunhofer IRB Verlag
Open this publication in new window or tab >>Effect of Use in High Pressure Die Casting on Vibenite®60 Tool Inserts Madeby Additive Manufacturing
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2016 (English)In: DDMC2016 Frauenhofer Direct Digital Manufacturing Conference: Conference Proceedings, March 2016, Berlin, Germany / [ed] B. Müller, Fraunhofer IRB Verlag, 2016Conference paper, Published paper (Refereed)
Abstract [en]

The thermo-physical and mechanical properties of Vibenite®60 was investigated in the as-manufactured, soft annealed and hardened state as well as after use in full scale high pressure die casting. Thermal conductivity in the as manufactured state was 23.3 to 27.5 W/mK in the temperature range from 25°C to 500°C. Annealing increased thermal conductivity to 25.0 up to 29.2 W/mK. Hardening reduced thermal conductivity of 19.8 to 26.1 W/mK. The tool wastested in production in the as fabricated state displayed a slight increase in thermal conductivity, which was interpreted as a slight tempering during use. Hardness measurements were made at room temperature and followed the same pattern as the thermo-physical properties. Rockwell and Vickers Hardness was lowest in the as lowest in the annealed state and hardest in the hardened state. Rockwell hardness was not affected by use in production while Vickers hardness decreased slightly.

Place, publisher, year, edition, pages
Fraunhofer IRB Verlag, 2016
Keywords
Tooling, 3D printing, additive manufacturing
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-29660 (URN)978-3-8396-1001-5 (ISBN)
Conference
DDMC2016 Frauenhofer Direct Digital Manufacturing Conference
Projects
ADDING
Funder
VINNOVA
Available from: 2016-03-28 Created: 2016-03-28 Last updated: 2018-09-12Bibliographically approved
Bogdanoff, T., Seifeddine, S. & Dahle, A. K. (2016). The effect of SI content on microstructure and mechanical properties of Al-Si alloy. La Metallurgia Italiana, 108(6)
Open this publication in new window or tab >>The effect of SI content on microstructure and mechanical properties of Al-Si alloy
2016 (English)In: La Metallurgia Italiana, ISSN 0026-0843, Vol. 108, no 6Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Milano: Associazione Italiana di Metallurgia, 2016
Keywords
Al-Si alloy, Fracture mechanism, Mechanical Properties, Dendritic eutectic growth, Microstructure
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-31156 (URN)2-s2.0-85008867852 (Scopus ID)
Available from: 2016-08-02 Created: 2016-08-02 Last updated: 2017-11-28Bibliographically approved
Seifeddine, S., Sjölander, E. & Bogdanoff, T. (2013). On the role of copper and cooling rates on the microstructure, defect formations and mechanical properties of Al-Si-Mg alloys. Materials Sciences and Applications, 4(3), 171-178
Open this publication in new window or tab >>On the role of copper and cooling rates on the microstructure, defect formations and mechanical properties of Al-Si-Mg alloys
2013 (English)In: Materials Sciences and Applications, ISSN 2153-117X, E-ISSN 2153-1188, Vol. 4, no 3, p. 171-178Article in journal (Refereed) Published
Abstract [en]

This paper aims to assess the role of Cu on Al-Si-Mg alloys, in a range of 0 - 5 wt%, qualitatively on microstructure, defect formation, in terms of porosity, and strength in the as-cast conditions. The ternary system of Al-Si-Mg, using the A356 alloy as a base material, were cast using the gradient solidification technique; applying three different solidification rates to produce directional solidified samples with a variety of microstructure coarsenesses. Microstructural observations reveal that as the Cu levels in the alloys are increased, the amounts of intermetallic compounds as well as the Cu concentration in the α-Al matrix are increased. Furthermore, the level of porosity is unaffected and the tensile strength is improved at the expense of ductility.

Place, publisher, year, edition, pages
Scientific Research Publishing, 2013
Keywords
Aluminium-Silicon Alloys, Microstructure, Mechanical Properties, Gradient Solidification
National Category
Metallurgy and Metallic Materials
Identifiers
urn:nbn:se:hj:diva-20207 (URN)10.4236/msa.2013.43020 (DOI)
Funder
Knowledge Foundation
Available from: 2013-01-09 Created: 2013-01-09 Last updated: 2018-09-13Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5753-4052

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