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The tensile and compression properties of hot extruded Mg99.2Ca0.6Mn0.2 (at%) alloy were tested, and the cyclic polarization curves and impedance spectroscopy of the alloy soaked in SBF solutions with various pH values were measured by electrochemical method so that the corrosion behavior of the alloy can be evaluated and the experimental foundation for preparation of magnesium implant materials was provided. The results show that the tensile failure of the alloy appears to be characteristic of quasi-cleavage fracture. The tensile strength, yield strength, compressive strength and elongation are 279 MPa, 251 MPa, 330 MPa and 11% at room temperature, respectively. The pH value of the solution has prominent effect on corrosion behavior. As the pH value increases, the arc radius of impedance spectroscopy and corrosion potential increase remarkably, whereas the corrosion current density decreases, and thus the corrosion resistance of the alloy is strengthened. There is only one time constant which appears at low frequency in phase angle plot. The corrosion rate can be significantly reduced by increasing pH value of the solution. The instantaneous corrosion rates of the alloy immersed in the solutions with pH value of 7.2 and 10.0 are 4.1 mm/a and 0.2 mm/a, respectively.

Mask stereolithography technology uses ultraviolet masks to print curable liquid materials. A key process for layer-by-layer bottom-up mask printing is the separation of cured layer from the vat bottom. For film-assisted separation, most studies focused on the separation process of the inert film that bonded to the vat bottom. The separation characteristics and mechanism of the widely used flexible film has not received much attention. In this investigation, based on liquid crystal display (LCD) mask stereolithography, separation processes of the inert film in both semi-flexible and flexible states were compared and analyzed. The results showed that the average maximum separation force of flexible film was reduced above 48 %, and the average separation energy was reduced above 22 % compared with the semi-flexible film for both large-area and array supports models. The flexible film can smooth separation process by reducing the stiffness of separation force curve. The reducing effect of separation force of flexible film was achieved by its large deformation and mixed-mode fracture mechanism.

Various combinations of diamond, moissanite, zircon, quartz, corundum, rutile, titanite, almandine garnet, kyanite, and andalusite have been recovered from the Dangqiong peridotites. More than 80 grains of diamond have been recovered, most of which are pale yellow to reddish-orange to colorless. The grains are all 100–200 µm in size and mostly anhedral, but with a range of morphologies including elongated, octahedral and subhedral varieties. Their identification was confirmed by a characteristic shift in the Raman spectra between 1325 cm−1 and 1333 cm−1, mostly at 1331.51 cm−1 or 1326.96 cm−1. Integration of the mineralogical, petrological and geochemical data for the Dongqiong peridotites suggests a multi-stage formation for this body and similar ophiolites in the Yarlung-Zangbo suture zone. Chromian spinel grains and perhaps small bodies of chromitite crystallized at various depths in the upper mantle, and encapsulated the UHP, highly reduced and crustal minerals. Some oceanic crustal slabs containing the chromian spinel and their inclusion were later trapped in suprasubduction zones (SSZ), where they were modified by island arc tholeiitic and boninitic magmas, thus changing the chromian spinel compositions and depositing chromitite ores in melt channels.

Brine concentration is of critical importance in achieving zero liquid discharge in modern industrial processes. The effect of osmotic agent (OA) on the system performance in the treatment of different concentrations of brine using osmotic membrane distillation (OMD) was investigated. Significant improvement in water flux for concentrating the hypersaline brine was achieved compared to conventional membrane distillation processes. By altering the hydrodynamic conditions and using different combinations of feed streams and osmotic agents, a mathematical approach was applied, for the first time, to reveal the contribution of temperature and concentration polarization on flux enhancement in treating highly saline brines. This improvement was found to be caused mainly by the temperature polarization on the OA side of membrane, with less contribution from the decrease in vapor pressure of the bulk of the OA. This work illustrates that OMD is a promising process for efficient concentration of highly saline streams such as those found in the chlor-alkali industry. During the concentration of the spent brine from the electrolyte cell (NaCl concentration from 180 g/L to 310 g/L), OMD was shown to be the more cost and energy efficient compared to conventional MD processes.

Diamond, moissanite and a variety of other minerals, similar to those reported from ophiolites in Tibet and northern Russia, have recently been discovered in chromitites of the Hegenshan ophiolite of the Central Asian Orogenic Belt, north China. The chromitites are small, podiform and vein-like bodies hosted in dunite, clinopyroxene-bearing peridotite, troctolite and gabbro. All of the analysed chromite grains are relatively Al-rich, with Cr# [100Cr/(Cr+Al)] of about 47–53. Preliminary studies of mainly disseminated chromitite from ore body No. 3756 have identified more than 30 mineral species in addition to diamond and moissanite. These include oxides (mostly hematite, magnetite, rutile, anatase, cassiterite, and quartz), sulfides (pyrite, marcasite and others), silicates (magnesian olivine, enstatite, augite, diopside, uvarovite, pyrope, orthoclase, zircon, sphene, vesuvianite, chlorite and serpentine) and others (e.g., calcite, monazite, glauberite, iowaite and a range of metallic alloys). This study demonstrates that diamond, moissanite and other exotic minerals can occur in high-Al, as well as high-Cr chromites, and significantly extends the geographic and age range of known diamond-bearing ophiolites.

In recent years diamonds and other exotic minerals have been recovered from mantle peridotites and high-Cr chromitites of a number of ophiolites of different age and different tectonic environments. Here we report a similar collection of minerals from the Sartohay ophiolite of Xinjiang Province, western China, which is characterized by having high-Al chromitites. Several samples of massive podiform chromitite with an aggregate weight of nearly 900 kg yielded diamonds, moissanite and other highly reduced minerals, as well as common crustal minerals. Thus far, more than 20 grains each of diamond and moissanite have been recovered from heavy mineral separates of the chromitites. The diamonds are all 100–200 μm in size and range in color from pale yellow to reddish-orange to colorless. Most of the grains are anhedral to subhedral octahedra, commonly with elongate forms exhibiting well-developed striations. They all display characteristic Raman spectra with shifts between 1325 cm−1 and 1333 cm−1, mostly 1331.51 cm−1 or 1326.96 cm−1. The moissanite grains are light blue to dark blue, broken crystals, 50–150 μm across, commonly occurring as small flakes or fragments. Their typical Raman spectra have shifts at 762 cm−1, 785 cm−1, and 966 cm−1. This investigation extends the occurrence of diamonds and moissanite to a Paleozoic ophiolite in the Central Asian Orogenic Belt and demonstrates that these minerals can also occur in high-Al chromitites. We conclude that diamonds and moissanite are likely to be ubiquitous in ophiolitic mantle peridotites and chromitites.

The electroless plating Ni–P is prepared on the surface of Mg–7.5Li–2Zn–1Y alloys with different pickling processes. The microstructure and properties of Ni–P coating are investigated. The results show that the Ni–P coatings deposited using the different pickling processes have a different high phosphorus content amorphous Ni–P solid solution structure, and the Ni–P coatings exhibit higher hardness. There is higher phosphorus content of Ni–P amorphous coating using 125 g/L CrO3 and 110 ml/L HNO3 (w=68%) than using 180 g/L CrO3 and 1 g/L KF during pre-treatment, and the coating structure is more compact, and the Ni–P coatings exhibit more excellent adhesion with substrate (Fc up to 22 N). The corrosion potential of Ni–P coating is improved and exhibits good corrosion resistance. As a result, Mg-7.5Li-2Zn-1Y alloy is remarkably protected by the Ni–P coating.

The microstructure evolution in a Mg­4.3Zn­0.7Y­0.6Zr (mass%) alloy was investigated during solution heat treatment from 300 to 500°C for 12 h. In the as-cast and solution-treated at 300°C for 12 h states, the microstructures are consisting of I-phase and i-Mg. After solution treated at 400°C for 12 h, besides I-phase and i-Mg, some long strip precipitates-which are determined as Zn2Zr phase-, also appear in the microstructure. In the solution-treated sample at 500°C for 12 h, small amounts of Zn2Zr and Mg0.97Zn0.03 phases have been found. With the increase of heat treatment temperature, the phase constituents for different states are: i-Mg + I-phase (as-cast)1⁄4 i-Mg + I-phase (300°C for 12 h)1⁄4 i-Mg + I-phase + W-phase + Zn2Zr (400°C for 12 h) 1⁄4 i-Mg + Zn2Zr + Mg0.97Zn0.03 (500°C for 12 h). [doi:10.2320/matertrans.M2013378]

Effects of ultrasonic treatment on microstructures were investigated by introducing the ultrasonic oscillation into AZ91 alloy melts. The results show that the ultrasonic treatment does not change the phase composition but has great influence on solidification microstructures. The area percentage of lamellar eutectic phase increases to the maximum when the applied ultrasonic power is increased to 600 W and then decreases gradually with the further increase of power; meanwhile, the average area of Al 8 Mn 5 phase owns a completely opposing variation trend. The area percentage of Mg 17 Al 12 decreases gradually with increasing the applied ultrasonic power. Mechanisms accounted for the refinement and fraction of different intermetallic phases were also discussed.