The effect of drawing deformation on the microstructure, texture and mechanical properties of ultra-high strength TC10 Ti-alloy bars were investigated. TC10 alloy bars with a diameter of 16.4 mm were warm-drawn to various reductions, followed by annealing and solution-aging treatments, after which microstructure and mechanical properties were characterized. The results indicate that with the increasing drawing deformation, α-grains elongate along the drawing direction and develop a strong <\mathrm{10}\overline{\mathrm{1}}\mathrm{0}> fiber texture. Grain refinement plus work-hardening collectively raise strength but reduce plasticity of the Ti-alloy bar. After annealing, recovery and recrystallization occur, leading to an initial strengthening and subsequent weakening of the <\mathrm{10}\overline{\mathrm{1}}\mathrm{0}> texture. The strength of the annealed alloy slightly decreases compared to the as-drawn state, while the ductility improves. Solution-aging treatment leads to the precipitation of fine, acicular secondary α-phases, further increasing the strength but reducing the plasticity of Ti-alloy. At a drawing deformation of 59%, the solution-aged alloy exhibits optimal comprehensive properties, achieving a tensile strength of 1402 MPa and an elongation of 11.0%. These findings provide a meaningful reference for determining the drawing process parameters of TC10 alloy bars used in fastener manufacturing.

Herein, work-pieces of TC11 Ti-alloy were made via powder metallurgy hot isostatic pressing (PM-HIP) technique. Then the tensile property of the as made TC11 Ti-alloys was studied at 500 ^oC for long-term (400 h), in terms of the variation of their microstructure and mechanical property with the thermal exposure via high-temperature tensile test, optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD) etc. The results show that the made TC11 Ti-alloy has good microstructure stability. After thermal exposure, the equivalent diameter of equiaxed α and the thickness of lamellar α remain basically at 3.7 μm and 2.5 μm. After long term exposure at 500 ^oC, the made TC11 Ti-alloy presents an improvement to a certain extent in tensile strength, while exposure at higher temperature the alloy shows a decrease in strength. The study suggests that the grain size change and the precipitation of α₂ phase, and silicides significantly affect the alloy performance. Moreover, based on the actual microstructure evolution process during thermal exposure, the possible pathways of Hall-Petch relationship parameter changes under this process are proposed.

The cold rolled commercial Ti-based alloy Ti₂AlNb sheets of 1 mm in thickness were prepared via multiple folding and rolling, and then subjected to solid solution treatment at 960 ^oC, followed by three type aging treatments in two-phase (B2 + α₂) region: 750 ^oC/4 h, 800 ^oC/4 h and 850 ^oC/4 h respectively. Then the effect of heat treatments on their microstructure, texture, and tensile properties was investigated, in terms of verifying the effect of reducing the anisotropy of alloy sheets and revealing the related formation mechanism of the layered texture structure parallel to the sheet surface within the sheet section. The results show that the microstructure of the sheet consists of B2-matrix, O-phase of various morphologies, and a small amount of equiaxed α₂-phase. The {001}<110> rotated cube texture and the {111}<uvw> texture of the B2-phase are alternately distributed along the thickness direction; the α₂-phase exhibits a typical T-type texture; influenced by orientation relationship inheritance, the orientation distribution of the O-phase is characterized by [100]//ND and [001]//TD. This layered structure originates from the inhomogeneous accumulation of shear strain in the surface region and compressive strain in the center during multi-pass rolling. At room temperatures, the solution-treated sheet exhibits pronounced tensile anisotropy, with the transverse direction (TD) tensile strength being significantly higher than that along the rolling direction (RD). The primary reason is that, under loading along TD, the T-type texture of the α₂-phase renders the prismatic <a> slip systems more difficult to activate, and the elongated lath structure along the rolling direction imposes a stronger geometrical barrier to dislocation motion in the TD. Aging heat treatment not only induces the precipitation of finely dispersed secondary acicular O-phase, thereby improving the microstructural homogeneity, but also weakens the direction dependence of prismatic <a> slip by strengthening the R-type texture of the α₂-phase. The synergistic effect of these two mechanisms significantly reduces the tensile anisotropy of the sheet.

The specified two type of rolled and rolled+drawn near β-Ti based alloy Ti-55531 bars respectively were subjected to solution at 760 ^oC for 1 h and air-cooled, followed by aging at 560 ^oC for 4 h then air-cooling. Then their microstructure, texture characteristics, and fracture toughness were systematically investigated, in terms of the influence of different thermomechanical processing routes on the crack propagation path. The results show that thermomechanical deformation can significantly refine the primary α-phase, leading to a refined and more homogeneous microstructure of the alloy bars. The bars subjected to drawing deformation exhibit pronounced fiber textures: β-phase <110>//AD and α phase <0001>//AD. Compared with the ϕ61 mm rolled bar, the ϕ12 mm bars exhibit improved plasticity and toughness while maintaining comparable strength. The ϕ12 mm bar prepared by rolling+drawing demonstrates the best strength-toughness balance, with a fracture toughness of 34.63 MPa·m^1/2, which is 43.5% and 19.7% higher than those of the ϕ61 mm and ϕ12 mm merely rolled bars, respectively. Furthermore, crack propagation analysis indicates that the existed strong texture in the rolled+drawn bars is conductive to triggering the crack deflection effect significantly, thereby achieving geometric toughening.

Porous aluminum is widely used in protective structures due to its advantages such as lightweight, having high energy absorption efficiency, and multi-functionality. However, the increasingly stringent service requirements for lightweight materials in engineering structures have highlighted the limitations of traditional porous aluminum, necessitating the development of new high-performance composite structures. To address this issue, Herein, a novel interpenetrating phase Al-based composites (IPCs), which ingeniously integrate ordered lattice structures with hollow struts and disordered Al-foam. The composites were fabricated using a conventional infiltration casting process, ensuring simplicity and practicality for engineering applications. Three distinct lattice structures with varying mechanical characteristics were selected as the reinforcing phase, leading to the design and preparation of three composite configurations. A comprehensive evaluation of their mechanical performance and deformation mechanisms was conducted through quasi-static compression tests. The results demonstrate that the composites successfully integrate the advantages of both the ordered lattice and the disordered foam. It maintains the characteristics of being lightweight and exhibits a stable stress response, while simultaneously significantly enhancing the macroscopic compressive strength and energy absorption capacity. Specifically, compared to the sum of the mechanical properties of its individual constituents, the proposed composite achieves a maximum increase of 58.90% in compressive strength and a remarkable maximum enhancement of 287.67% in energy absorption, indicating a pronounced synergistic effect. In summary, the developed Al-based IPCs with hollow struts not only features a simple and potentially scalable preparation process but also achieves an excellent combination of strength and toughness while maintaining low density, providing a new design strategy and a viable technical pathway for the development of next-generation high-performance lightweight protective materials.

With the rapid development of ultra-high-speed and low-power Schottky barrier diode (SBD), the height and stability of the Schottky barrier have become a critical factor driving the continued evolution of the electronic and information technology industry. However, challenges such as uncontrollable surface quality, crack formation, and a lack of theoretical guidance for process optimization limit practical applications. Herein, Ni5Pt alloy films were prepared on substrates of single crystal Si with orientations of (100) and (111) respectively via magnetron sputtering technique by varying the substrate temperature and deposition time. The influence of sputtering parameters on the microstructure and surface morphology of the acquired films was characterized, while the mechanism related to the cracking failure of the films was postulated. Results reveal that the growth mechanism of Ni5Pt conforms to Stranski-Krastanov (SK) model. Surface roughness of films increases with the increasing deposition time and the decreasing substrate temperature, besides, which also depends on the crystallographic orientation of the basal plane of substrates. A cracking criterion based on residual stress was proposed, thereafter, the optimal sputtering parameters were established. The findings provide not only an important theoretical guidance for obtaining a Schottky barrier layer with good interface continuity and high barrier stability, but also a meaningful reference for the R & D of high-performance Schottky barrier diode devices in the future.

Continuous SiC fiber reinforced SiC ceramic matrix composites are promising high-temperature structural materials for aerospace applications, whose performance is strongly influenced by the interphase between the fiber and the matrix. Although traditional interphases such as pyrolytic carbon and hexagonal boron nitride possess a layered structure, the resistance against high-temperature steam oxidation is relatively poor. This work focused on the B-N-Si ternary system as a novel interphase candidate. The effect of Si content on the structure, mechanical properties, and high-temperature water vapor oxidation behavior of B-N-Si interphase material were systematically investigated by means of high-throughput fabrication and characterization technique. The results showed that all B-N-Si coatings deposited at room temperature exhibited an amorphous structure, with silicon atoms preferentially replacing boron atoms and forming Si-N bonds. When silicon content was in the range of 7.57%-19.66% (atomic fraction), all coatings satisfied the mechanical requirements for crack deflection. Moreover, when the silicon content exceeds 11.76%, the coatings could swell up after oxidation at 900 ^oC in a 90%H₂O-10%O₂ atmosphere due to the formation of B₂O₃·SiO₂ glass phase, exhibiting remarkable self-healing capability and oxidation resistance.

Novel organic-inorganic composite conversion liquids were designed and prepared, aiming to address troubles related with the yellowing and inadequate corrosion resistance of the silane film for galvanized fasteners. First, KH-550 (3-amino propyl triethoxy silane) and KH-560 (3-(2,3-epoxy propoxyoxy) propyl trimethoxy silane) were mixed and hydrolyzed to get organic component, and two series liquid silicates K₂SiO₃ and Na₂SiO₃ were prepared by reaction of KOH and NaOH with SiO₂ of varying proportion to get silicates of different modulus respectively as inorganic component. Next the novel composite organic-inorganic conversion liquids were obtained by compounding the organic component with the two series inorganic components at 9:1-1:9 respectively. Further, galvanized fasteners were immersed in the liquids for 30-60 s, subsequent dried, and cured at 80-120 ^oC for 10 min and followed at 180-200 ^oC for 30 min, thereby, an organic-inorganic conversion film is formed on the galvanized fasteners. The storage stability of the conversion solution and the yellowing resistance of the conversion film were evaluated by macroscopic observation. Results of neutral salt spray testing and copper sulfate titration testing reveal that the corrosion resistance of the potassium silicate containing conversion films was superior to the sodium silicate containing conversion films. The corrosion resistance of conversion films with varying proportion of organic component was assessed by the forementioned way (note, by taking M1(9:1) as an example, herewith M1 presents modulus 1 and 9:1 presents the ratio of the two components). Besides, the corrosion resistance of conversion films prepared with conversion liquids composed of varying proportion of organic component to potassium silicate series of different modulus was assessed by the forementioned way. Meanwhile, the morphology, composition, mechanical properties and corrosion resistance of the conversion film, which presents the best corrosion resistance were characterized by means of scanning electron microscopy, energy spectroscopy, pencil hardness tester, and polarization curve test. The results showed that the prepared films M₁(9:1), M₁(8:2), M₁(7:3), M₁(1:9), M₂(9:1), M₂(8:2) and M₃(9:1) all showed a clear and transparent state, without delamination or gel, showing good storage stability. After 72 h salt spray test, the surface of the M₃(9:1) conversion film remained intact and clean, without any white rust or red rust, showing the best corrosion resistance. The film is transparent, eliminating the yellowing phenomenon of traditional silane films. SEM observation showed that the film was compact and uniform, tightly bound to the matrix, and had excellent physical shielding performance. The results of the pencil hardness test and adhesion test further confirm that the film has good mechanical properties.