Bulk metallic glasses (BMGs) are promising for multifunctional and structural application in different industries. However, the limited size of BMGs hinders their further application. The welding of BMGs has shown the possibility of getting rid of the casting size limitation. The heat-affected zone (HAZ) and fusion zone (FZ) often undergo severe crystallization during the welding process. It is still unclear whether the crystallization occurs during the heating process or the cooling process. To figure out the crystallization mechanisms of Zr-based BMGs during the electron beam welding process, the Zr-based BMGs with the composition of Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 were remelted by electron beam. The microstructures of the HAZ and the remelting zone (RZ) were analyzed. The thermal field of the electron beam welding was obtained by the finite element method (FEM). The critical conditions for crystallization during the heating and cooling processes were obtained by differential scanning calorimetry (DSC) and the Kissinger equation. The results show that the Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 in the HAZ undergoes severe crystallization, while the Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 in RZ keeps amorphous state after the remelting process. The low cooling rate in the HAZ is responsible for its crystallization.

The traditional fusion welding of carbon nanotubes (CNTs) reinforcement aluminium matrix composites has serious welding defects due to the violent interfacial reaction and the brittle secondary phase. In this paper, friction stir welding (FSW), a solid-phase welding technique, was applied to join the CNT/Al matrix composites. The result shows that the tensile strength of the FSW joint fabricated at 800 rev min^–1 and 100 mm min^–1 is 511 MPa, reaching 92.1% of the CNT/Al composites. After FSW, the original CNTs were damaged and formed the nano Al₄C₃ phase. Orowan strengthening of the Al₄C₃ phase, dislocation strengthening and grain refinement of FSW are the predominant strengthening mechanism for the joints. The great interfacial bonding between nano Al₄C₃ and matrix benefits the joint mechanical properties as well.

In this paper, silver nanowires (AgNWs) with a diameter of 40 nm and a length of 45 μm were dispersed into an ethanol solution to prepare AgNW solutions with concentrations of 1, 2, and 3 mg/mL, respectively. The AgNW solutions were then deposited on a glass substrate using spin-coating at 1000, 2000, and 3000 rpm for 45 s, respectively, to prepare transparent electrodes. The results showed that the distribution of AgNWs on the substrate increased in density with the increase in the AgNW solution concentration and the decrease in spin speed. The effect of concentration on the distribution of AgNWs was greater than that of the spin speed. The transmittance of each electrode was between 84.19% and 88.12% at 550 nm, the average sheet resistance was between 20.09 and 358.11 Ω/sq, the highest figure of merit (FoM) was 104.42, and the lowest haze value was 1.48%. The electrode prepared at 1000 rpm with a concentration of 2 mg/mL and that prepared at 3000 rpm with a concentration of 3 mg/mL were very similar in terms of the average sheet resistance, transmittance at 550 nm, FoM, and haze value; thus, these two electrodes could be considered equivalent. The haze value of the electrode was positively correlated with the spin speed at low concentration, but that relationship became inverse as the concentration rose. For the AgNWs used in this experiment with an aspect ratio of 1125, the concentration of the AgNW solution should reach at least 2 mg/mL to ensure that the FoM of the electrode is greater than 35.

The application range of fused silica optical components can be expanded and the cost of fused silica components can be reduced by depositing the same material film on fused silica substrate. However, due to the different manufacturing process, the performance of ALD SiO₂ film is lower than that of fused silica substrate, which also limits the use of this process. In this paper, ALD SiO₂ film with different thicknesses were deposited, and then the structure and properties were tested. Finally, the ALD SiO₂ film was treated via the annealing process. Transmission electron microscopy (TEM) showed that the ALD SiO₂ film had good compactness and substrate adhesion. The Raman spectra showed that the ALD SiO₂ film and substrate had the same structure, with only slight differences. The XRD pattern showed that ALD-fused silica did not crystallize before or after annealing. The infrared spectra showed that there was an obvious Si-OH defect in the ALD SiO₂ film. The laser damage showed that the ALD SiO₂ film had a much lower damage threshold than the fused silica substrate. The nanoindentation showed that the mechanical properties of the ALD SiO₂ film were much lower than those of the fused silica substrate. After a low-temperature annealing treatment, the ALD SiO₂ film Si-OH defect was reduced, the ALD SiO₂ film four-member ring content was increased, the elastic modulus of the ALD SiO₂ film was increased from 45.025 GPa to 68.025 GPa, the hardness was increased from 5.240 GPa to 9.528 GPa, and the ALD SiO₂ film damage threshold was decreased from 5.5 J/cm² to 1.3 J/cm².

Fused silica was polished to a high quality by a CO₂ laser beam with a rapid scanning rate. The rapid scanning rate produced a line laser heat source, resulting in a “polishing line” during the polishing process. The Taguchi method was used to evaluate the comprehensive influence of polishing process parameters on the polishing qualities. Four factors, namely the length of laser reciprocating scanning (A), laser beam scanning speed (B), feed speed (C), and defocusing amount (D), were investigated in this study. The optimal process parameter combination (A1B1C1D1) was obtained. The surface roughness of fused silica was reduced from Ra = 0.157 μm to 0.005 μm. Through analysis of variance (ANOVA), it was found that laser beam scanning speed (B) had a significant influence on the polishing quality. The interaction of the two factors plays a decisive role in the determination of the best process parameters, and the influence of other multi-factor interaction can be ignored; the interaction between A × B is the largest, with a contribution of 42.69%.