The thixoforging technology has been proved as an effective method to fabricate the in situ Mg2Sip/AM60B composite with excellent performances. The effects of reheating temperature on microstructure and tensile properties have been investigated. The results indicate that the liquid amount, the solubility of Al in α-Mg particles, and the coarsening of the α-Mg particles are changed as the reheating temperature changes, and thus the subsequent solidification behavior and plastic deformation are thereby changed. The morphology of the Mg2Si particle also varies as the reheating temperature rises owing to partial remelting operating in the edges and corners of the particles. The best ultimate tensile strength and elongation of 209 MPa and 11.9% of the thixoforged composite, which are 93 and 138% higher than the traditional permanent mold casting respectively, are obtained under the reheating temperature of 600 °C.

We have recently reported the repair of carious enamel using a full-length amelogenin–chitosan hydrogel through guided stabilization and growth of mineral clusters. The objective of this study was to further evaluate the enamel repair potential of smaller amelogenin peptides like LRAP (leucine-rich amelogenin peptide) and compare their efficiency with their full-length counterpart. The demineralized tooth slices treated with a single application of LRAP–chitosan hydrogel for 3 days showed a dense mineralized layer consisting of highly organized enamel-like apatite crystals. Focus-ion beam technique showed a seamless growth at the interface between the repaired layer and native enamel. There was a marked improvement in the surface hardness after treatment of the demineralized sample with almost 87% recovery of the hardness value to that of sound enamel sections. This current approach can inspire the design of smaller peptide analogues based on naturally occurring amelogenin as a competent, low-cost, and safe strategy for enamel biomimetics to curb the high prevalence of incipient dental caries.

Carbon fiber reinforced plastic (CFRP) is an expensive composite which has become valuable material as the demand for this composite increased in the industries. It is suitable to be used in automotive, aerospace, and aircraft because of its properties which is stronger than steel and also stiffer than titanium while retaining its lighter weight. However machining of CFRP is a mess to machinist due to its nature which is abrasive. The paper presents the wear mechanism on solid carbide cutting tool during milling CFRP. The wear mechanism is observed under dry and chilled air machining. The machining parameters tested were at cutting speed of 200 m/min with constant feed rate and depth of cut. For both dry and chilled air machining, it is observed that carbide cutting tool experienced abrasive wear which has been influenced by abrasive powdering chips and fibers during milling CFRP. Under microscope and scanning electron microscope, the abrasive wear is represented by shiny and polish area on the cutting tool respectively. This abrasive wear is observed higher under dry machining compared to the chilled air machining which was due to the heat generated during machining. Thus, chilled air has a potential of improving machinability of CFRP by using solid carbide cutting tool.

In this study, the temperature gradient on lunar surface was simulated by deep cryogenic treatment and cryogenic thermocycling. The influence of these treatments on room and low temperature tensile properties and fracture behavior of the as-cast Mg–10Gd–3Y–0.5Zr alloy was then investigated. The results have shown that the cryogenic treatments caused the precipitation of Mg24(Gd, Y)5 phase and improved the ductility of the alloy. The deep cryogenic treatment almost has no influence on the tensile properties of the alloy, while the cryogenic thermocycling slightly improve its tensile properties at room temperature and slightly deteriorate the ultimate tensile strength of the alloy at low temperature. The cleavage fracture is the main fracture mechanism at both room and low temperatures. To conclude, this alloy can withstand the huge temperature gradient on the lunar surface and shows application perspective.

Understanding magnetosome magnetite biomineralization is of fundamental interest to devising the strategies for bioinspired synthesis of magnetic materials at the nanoscale. Thus, we investigated the early stages of magnetosome formation in this work and correlated the size and emergent crystallinity of magnetosome nanoparticles with the changes in chemical environment of iron and oxygen by utilizing advanced analytical electron microscopy techniques. We observed that magnetosomes in the early stages of biomineralization with the sizes of 5–10 nm were amorphous, with a majority of iron present as Fe3+, indicative of ferric hydroxide. The magnetosomes with intermediate sizes showed partially crystalline structure with a majority of iron present as Fe3+ and trace amounts of Fe2+. The fully maturated magnetosomes were indexed to magnetite. Our approach provides spatially resolved structural and chemical information of individual magnetosomes with different particle sizes, attributed to magnetosomes at different stages of biomineralization.

Conventional retrogression and re-aging (RRA) treatment could not be put to good use for combination property of Al–Zn–Mg–Cu alloys. The new RRA treatment fitted for spray formed Al–Zn–Mg–Cu alloy was investigated by transmission electron microscope, tensile, and conductivity tests. The results show that the pre-aging treatment with under aging of 120 °C for 16 h is beneficial for the redissolution of matrix precipitates during retrogression treatment. With the retrogression of 200 °C for 8 min, grain boundary precipitates are discrete and the corrosion resistance of the alloy is drastically increased. After re-aging (120 °C for 24 h) the strength of the alloy is increased again. According to the above-mentioned new RRA treatment, the ultimate tensile strength, yield strength, elongation, and conductivity of the alloy are 791 MPa, 736 MPa, 8.5%, and 39.5% IACS respectively, which is higher than that after conventional RRA treatment.

Although there are numerous reports on the synthesis of spherical materials, the development of new approaches remains important for theory construction to realize tailor-made synthesis of spherical materials. Herein, we report the synthesis of polydispersed spherical particles of H2Ti2O5 intercalated with a polyethyleneamine, such as an ethylenediamine, on the basis of a solvothermal treatment using concentrated polyethyleneamine aqueous solutions. The diameter of the micrometer-sized spheres enlarged with increasing amine concentration in the reaction solution. It was speculated that high ionic strength caused the self-assembly of polyethyleneamine-intercalated H2Ti2O5, resulting in the formation of spherical agglomerates. The spheres had a specific a surface area of 200 m2 g−1 and approximately 5 nm pores, and these values were controlled by amine concentration and treatment time. Conversion to single phase anatase and rutile without changes in spherical morphology was achieved by heat treatment. The present approach may assist with the design morphology of agglomerates.

Incineration or disposal of carbon fiber waste from the aircraft industry leads to serious energy consumption and environmental pollution. The use of this waste as reinforcement is a wise approach to appreciate the high performance of the carbon fiber. In this study, the sliding wear and frictional behavior of recycled carbon fiber prepreg (rCFP) reinforced polypropylene (PP) prepared via melt compounding method using an internal mixer were studied. The samples were categorized into PP reinforced by carbon fiber with resin (A) and carbon fiber without resin (B). Pin-on-disc method was utilized to evaluate the effect of rCFP content and physical condition of fibers on tribological performance of the composites. The results were supported by morphological analyses using scanning electron microscopy. It was found that polymer composites B for rCFP without resin exhibited better tribological performance than composites category-A. The addition of rCFP into PP was observed to increase its wear resistance with minimum coefficient of friction achieved at 3 wt% of rCFP content for both polymer composites.

In this paper, hierarchical nanostructures of BiOBr/AgBr on electrospun carbon nanofibers (CNFs) were prepared by combination of electrospinning and carbonization. Compared with the smooth surface of CNFs, the rough surface with hierarchical nanostructures of BiOBr/AgBr can be obtained by adding the certain amount of BiOBr/AgBr precursors into the spinning solution. The as-prepared composite CNFs exhibited highly photocatalytic activities for degradation of rhodamine-B and reduction of p-nitrophenol under the visible-light irradiation and at room temperature. Furthermore, the as-prepared composite CNFs showed the favor separation, recovery, and cyclic utilization properties.