Publications by authors named "Jean-Marie Dubois"

Article Synopsis
  • A new binary phase with an Al-Ir composition was found, crystallizing in a trigonal structure with specific unit cell dimensions; this structure is derived from the NiAl type, with aluminum atoms replacing nickel.
  • Single-crystal imaging has shown the supercell structure and confirmed its metastable nature through thermal analysis.
  • The compound exhibits metallic properties with significant electronic structure characteristics, including hybridization between Al and Ir states, which contributes to its stability against deviations from traditional electron count rules.
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A new ternary phase with a composition AlVSn ( = 0.19) has been found during investigation of the Al-V-Sn ternary system. Single-crystal X-ray diffraction measurements reveal that this ternary phase crystallizes with an orthorhombic structure with = 5.

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After gas atomization, a quasicrystalline powder based on aluminium was used to prepare a thick coating by high-velocity oxygen-fuel flame torch spraying. This layer was deposited on top of a bond-coat layer on a steel plate. A post-spraying annealing treatment turned the two layers to their stable state, a γ-brass crystal and an icosahedral quasicrystal, respectively.

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The discovery in 1987 of stable quasicrystals in the Al-Cu-Fe system was soon exploited to patent specific coatings that showed reduced friction in ambient air against hard antagonists. Henceforth, it was possible to develop a number of applications, potential or commercially exploited to date, that will be alluded to in this topical review. A deeper understanding of the characteristics of complex metallic alloys (CMAs) may explain why material made of metals like Al, Cu and Fe offers reduced friction; low solid-solid adhesion came later.

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Additive manufacturing processes allow freeform fabrication of the physical representation of a three-dimensional computer-aided design (CAD) data model. This area has been expanding rapidly over the last 20 years. It includes several techniques such as selective laser sintering and stereolithography.

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This article aims at an account of what is known about the potential for applications of quasicrystals and related compounds, the so-called family of Complex Metallic Alloys (CMAs‡). Attention is focused at aluminium-based CMAs, which comprise a large number of crystalline compounds and quasicrystals made of aluminium alloyed with transition metals (like Fe or Cu) or normal metals like Mg. Depending on composition, the structural complexity varies from a few atoms per unit cell up to thousands of atoms.

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