Wear Behavior of a Heat-Treatable Al-3.5Cu-1.5Mg-1Si Alloy Manufactured by Selective Laser Melting.

In this study, the wear behavior of a heat-treatable Al-7Si-0.5Mg-0.5Cu alloy fabricated by selective laser melting was investigated systematically.

Viscous Flow of Supercooled Liquid in a Zr-Based Bulk Metallic Glass Synthesized by Additive Manufacturing.

The constraint in sample size imposed by the critical cooling rate necessary for glass formation using conventional casting techniques is possibly the most critical limitation for the extensive use of bulk metallic glasses (BMGs) in structural applications. This drawback has been recently overcome by processing glass-forming systems via additive manufacturing, finally enabling the synthesis of BMGs with no size limitation. Although processing by additive manufacturing allows fabricating BMG objects with virtually no shape limitation, thermoplastic forming of additively manufactured BMGs may be necessary for materials optimization.

Mechanochemical reaction of Al and melamine: a potential approach towards the in situ synthesis of aluminum nitride-carbon nanotube nanocomposites.

In the current study, an inexpensive solid-state mechanochemical technique is proposed for the in situ synthesis of nanostructured aluminum nitride (AlN) and carbon nanotubes (CNTs). The CNTs and nitrogen-doped CNTs are synthesized through a novel bottom-up milling approach in which melamine as the solid source of both carbon and nitrogen is milled with aluminum. However, the efficiency of CNT formation remarkably enhances when the milled powder is exposed to a subsequent heat treatment.

High strength nanostructured Al-based alloys through optimized processing of rapidly quenched amorphous precursors.

We report the methods increasing both strength and ductility of aluminum alloys transformed from amorphous precursor. The mechanical properties of bulk samples produced by spark-plasma sintering (SPS) of amorphous Al-Ni-Co-Dy powders at temperatures above 673 K are significantly enhanced by in-situ crystallization of nano-scale intermetallic compounds during the SPS process. The spark plasma sintered AlNiCoDy bulk specimens exhibit 1433 MPa compressive yield strength and 1773 MPa maximum strength together with 5.

Strain Distribution Across an Individual Shear Band in Real and Simulated Metallic Glasses.

Because of the fast dynamics of shear band formation and propagation along with the small size and transient character of the shear transformation zones (STZs), the elementary units of plasticity in metallic glasses, the description of the nanoscale mechanism of shear banding often relies on molecular dynamics (MD) simulations. However, the unrealistic parameters used in the simulations related to time constraints may raise questions about whether quantitative comparison between results from experimental and computational analyses is possible. Here, we have experimentally analyzed the strain field arising across an individual shear band by nanobeam X-ray diffraction and compared the results with the strain characterizing a shear band generated by MD simulations.

Mechanochemical synthesis of nanostructured metal nitrides, carbonitrides and carbon nitride: a combined theoretical and experimental study.

Nowadays, the development of highly efficient routes for the low cost synthesis of nitrides is greatly growing. Mechanochemical synthesis is one of those promising techniques which is conventionally employed for the synthesis of nitrides by long term milling of metallic elements under a pressurized N or NH atmosphere (A. Calka and J.

Deformation at ambient and high temperature of Laves phases-ferrite composites.

The mechanical behavior of a FeZrCr alloy has been studied at ambient and high temperature. This FeZrCr alloy, whoose microstructure is formed by alternate lamellae of Laves phase and ferrite, constitutes a very simple example of an CMA phase composite. The role of the Laves phase type was investigated in a previous study while the present work focuses on the influence of the microstructure length scale owing to a series of alloys cast at different cooling rates that display microstructures with Laves phase lamellae width ranging from ∼50 nm to ∼150 nm.

Production of Porous β-Type Ti-40Nb Alloy for Biomedical Applications: Comparison of Selective Laser Melting and Hot Pressing.

We used selective laser melting (SLM) and hot pressing of mechanically-alloyed β-type Ti-40Nb powder to fabricate macroporous bulk specimens (solid cylinders). The total porosity, compressive strength, and compressive elastic modulus of the SLM-fabricated material were determined as 17% ± 1%, 968 ± 8 MPa, and 33 ± 2 GPa, respectively. The alloy's elastic modulus is comparable to that of healthy cancellous bone.

Structural and Mechanical Characterization of ZrTiCuNiAl Bulk Metallic Glass.

Thermal stability, structure and mechanical properties of the multi-component ZrTiCuNiAl bulk metallic glass have been studied in detail. The glassy material displays good thermal stability against crystallization and a fairly large supercooled liquid region of 52 K. During heating, the alloy transforms into a metastable icosahedral quasicrystalline phase in the first stage of crystallization.