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The FurnaSEM microfurnace was installed in the chamber of a scanning electron microscope to carry out in situ experiments at high temperatures and test its limits. The microfurnace was used in combination with different types of detectors (Everhart–Thornley for the collection of secondary electrons in a high vacuum, gas secondary electron detector for the specific collection of secondary electrons in the presence of gas, and Karmen© detector for the collection of backscattered electrons at high temperature). Experiments carried out on various samples (metal alloys and ceramics) show that the microfurnace operates in both high-vacuum and low-vacuum modes. Temperature ramp rates during temperature cycles applied to the sample range from 1 to 120 °C/min (temperature rise) and 1 to 480 °C/min (controlled and natural cooling). The maximum temperature at which images were recorded up to 25 k × magnification was 1340 °C, with a residual air atmosphere of 120 Pa. The choice of a flat furnace with the sample placed directly above it has enabled innovative experiments to be carried out, such as low-voltage imaging (using a shorter working distance—up to 10 mm—than is possible with conventional furnaces), 3D imaging (by tilting the stage by up to 10°), and high-temperature backscattered electron imaging (using a dedicated detector). [ABSTRACT FROM AUTHOR]

Exploring novel materials with large magnetocaloric effect and excellent mechanical properties near room temperature (RT) are highly desired for Ni-Mn based Heusler alloys. In this work, the martensitic transformation, magnetic properties, and mechanical properties of Ni50-xCoxMn50-yTiy (x = 13–15, y = 13–16) alloys were systematically investigated by tuning Co or Ti contents. The magnetism of austenite was enhanced with an increase in Co or Ti content. 5M and 6M martensites were observed in Ni-Co-Mn-Ti alloys by transmission electron microscopy. The Ni36Co14Mn35Ti15 alloy with a large magnetocaloric effect was found near room temperature by tuning composition. The largest magnetization change (ΔM) and magnetic entropy change (ΔSm) in the Ni36Co14Mn35Ti15 non-textured polycrystalline alloy obtained during martensitic transformation under the magnetic field of 5 T were about 106 emu/g and 19.3 J kg−1 K−1, respectively. Furthermore, the maximum compressive strength and ductility for the Ni36Co14Mn35Ti15 as-cast alloy can exceed 1220 MPa and 15%, respectively. The fracture mechanism and bonding interaction were analyzed by a scanning electron microscope and first-principles calculations. [ABSTRACT FROM AUTHOR]

An all-optical technique has been used to provide the first direct measurement of anisotropic minority-carrier diffusion in an ordered alloy of GaInP. Direct imaging of the minority-carrier diffusion distribution resulting from generation at a quasipoint source is obtained using an optical microscope coupled to a scanning electron microscope. Minority-carrier diffusion lengths ranging from 3 to 60 μm are measured by this technique in double heterostructures of GaInP, GaAs, and GaInAs, providing a key parameter of interest to the performance of state-of-the-art triple junction solar cells. Here we show a direct measurement of anisotropy in minority-carrier mobility in ordered GaInP, which is evident in the oval-shaped distribution of the recombination luminescence. A factor of 1.6 increase in minority electron mobility along the [110] major axis is reported. [ABSTRACT FROM AUTHOR]

Examines the microstructural evolution of an SmTM[sub7.3] alloy during different stages of heat treatment under a conventional scanning electron microscope. Microstructures of the alloy; Correlation between the coercivity and heat treatments; Evolution of the platelet phase, the zonal phase and the grain boundary phase during isothermal aging.

Tensile ductility of the Ti-based composites, which consist of a β-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000MPa) and strain (about 35%-40%) but show a distinct difference in their tensile plasticity. The alloy Ti71.8Nb14.1Ni7.4Al6.7 fractures at the yield stress while the alloy Ti71.8Nb14.1Co7.4Al6.7 exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys. [ABSTRACT FROM AUTHOR]

A facile method was utilized for the construction of the bioinspired superhydrophobic Mg–Li alloy surfaces with peonylike micronanoscale hierarchical structures. The resultant materials were characterized by scanning electron microscope, x-ray photoelectron spectroscopy, and water contact angle measurements. The obtained Mg–Li alloy surfaces presented the dramatically improved corrosion resistance and long-term stable superhydrophobic properties with a static water contact angle of about 160° and a small sliding angle of less than 5°, which may extend the practical application of Mg–Li alloys in industrial and high-technology fields. [ABSTRACT FROM AUTHOR]

Based on compressive tests, static on 810 material test system and dynamic on the first compressive loading in split Hopkinson pressure bar (SHPB) tests for Pr-Nd alloy cylinder specimens at high strain rates and temperatures, this study determined a J-C type [G. R. Johnson and W. H. Cook, in Proceedings of Seventh International Symposium on Ballistics (The Hague, The Netherlands, 1983), pp. 541-547] compressive constitutive equation of Pr-Nd alloy. It was recorded by a high speed camera that the Pr-Nd alloy cylinder specimens fractured during the first compressive loading in SHPB tests at high strain rates and temperatures. From high speed camera images, the critical strains of the dynamic shearing instability for Pr-Nd alloy in SHPB tests were determined, which were consistent with that estimated by using Batra and Wei's dynamic shearing instability criterion [R. C. Batra and Z. G. Wei, Int. J. Impact Eng. 34, 448 (2007)] and the determined compressive constitutive equation of Pr-Nd alloy. The transmitted and reflected pulses of SHPB tests for Pr-Nd alloy cylinder specimens computed with the determined compressive constitutive equation of Pr-Nd alloy and Batra and Wei's dynamic shearing instability criterion could be consistent with the experimental data. The fractured Pr-Nd alloy cylinder specimens of compressive tests were investigated by using 3D supper depth digital microscope and scanning electron microscope. [ABSTRACT FROM AUTHOR]