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Characterization of martensite-austenite constituents and micro-hardness in intercritical reheated and coarse-grained heat affected zones of API X70 HSLA steel
Download2017-01-01
Mohammadijoo, M., Valloton, J., Collins, L., Henein, H., Ivey, D.G.
The thermal cycles that high strength low alloy (HSLA) low carbon steels experience during welding inevitably affect the microstructure and mechanical properties of the weld joints. It is generally agreed that the coarse-grained heat affected zone (CGHAZ) and the intercritical reheated...
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2019-01-01
Herlach, D.M., Burggraf, S., Reinartz, M., Galenko, P.K., Rettenmayr, M., Gandin, Ch.-A., Henein, H., Mullis, A., Ilbagi, A., Valloton, J.
The dendrite growth velocity in Al75Ni25 melts has been measured in a containerless procedure as a function of undercooling using an electromagnetic levitation technique both in the Earth laboratory and in Space on board the International Space Station. The growth shows an anomalous behavior...
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EFFECTS OF SCANDIUM ON HYPO-EUTECTIC ALUMINUM COPPER MICROSTRUCTURES UNDER LOW SOLIDIFICATION RATE CONDITIONS
Download2017-11-01
Bogno, A.-A., Valloton, J., Henein, H., Ivey, D.G., Locock, A.J., Gallerneault, M.
This work addresses the microstructures and mechanical properties of Al-4.5 wt% Cu alloys containing 0.1, 0.2 and 0.4 wt% Sc that were solidified under low cooling rate conditions (< 1ºC/s) and then heat treated. The samples were solidified in a differential scanning calorimeter before being heat...
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2019-01-01
Bogno, A.-A., Henein, H., Ivey, D.G., Valloton, J., Reinhart, G., Sediako, D., Gallerneault, M.
This paper reports on the characterization of rapidly solidified Al-4.5 wt% Cu-xSc (x= 0.1, 0.2 or 0.4 wt %). The effect of micro-additions of Sc (up to 0.4 wt %) was examined through microstructural analysis of rapidly solidified, as well as aged samples, by means of electron microscopy, x-ray...
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2022-01-01
Valloton, J., Mahdi, N., Rabago, L., Chung, J., Henein, H.
Al-33wt%Cu eutectic droplets were rapidly solidified using Impulse Atomization, a drop tube technique. The samples were then processed in situ in an SEM using an HTN-0101 MEMS heating chip manufactured by Norcada. The temperature of the chip, as well as the heating and cooling rates, can be...
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2020-01-01
Henein, H., Bogno, A.-A., Hearn, W., Valloton, J.
Cubic metallic alloys generally grow along 〈100〉 directions due to the anisotropy of the solid-liquid interfacial energy. Under rapid solidification conditions, dendrites may deviate from 〈100〉 and develop unusual morphologies. Here, Al-alloy droplets (Al-4.5Cu, Al-10Si, Al-1.9Fe, Al-33Cu, all in...
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2017-01-01
Valloton, J., Herlach, D.M., Henein, H., Sediako, D.
Rapid solidification of D2 tool steel is investigated experimentally using ElectroMagnetic Levitation (EML) under terrestrial and reduced gravity conditions and Impulse Atomization (IA), a drop tube type of apparatus. IA produces powders 300 to 1400 μm in size. This allows the investigation of a...
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2018-06-01
Hearn, W., Bogno, A.-A., Spinelli, J.E., Valloton, J., Henein, H.
Hypo-eutectic Al-Si alloys are widely used in both the automotive and aerospace industries, however, they still have limited usage as structural materials, due to the inherent morphology of the Si phase that forms within the eutectic structure. This non-ideal Si morphology can be modified, via...
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2017-12-05
Valloton, J., Gawor, S., Henein, H.
Numerous previous researchers have used nucleation models as part of their simulation of droplet solidification. None of these have verified the nucleation portion of these models with experimental results. In this work, a heterogeneous nucleation model based on the classical nucleation theory...
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2021-01-01
Valloton, J., Bogno, A.-A., Rappaz, M., Henein, H.
Rapid solidification of Al-Cu droplets of eutectic composition was carried out using Impulse Atomization (a type of drop tube). Two distinct morphologies were observed: an irregular undulated eutectic assumed to form during recalescence, followed by a regular lamellar eutectic. The volume...