Microstructure Properties Research Articles

Influence of interface on microstructure and mechanical properties of laser-direct energy deposited Ti60 alloy

Influence of interface on microstructure and mechanical properties of laser-direct energy deposited Ti60 alloy

Influence of post-heat treatments on the microstructure and mechanical properties of Inconel 738 produced by laser directed energy deposition

Influence of post-heat treatments on the microstructure and mechanical properties of Inconel 738 produced by laser directed energy deposition

3D-printed laponite bioceramic triply periodic minimal surface scaffolds with excellent bioactivity for bone regeneration

Laponite (LAP) is a promising biomaterial for bone regeneration due to its reliable biocompatibility and excellent osteoinductivity in bone tissue engineering. However, the personalized manufacture of LAP bioceramic scaffolds with controlled complex architecture and high porosity remains challenging. This study used vat photopolymerization (VPP) to manufacture LAP bioceramic scaffolds with high precision and biological activity. We first selected a 40 wt% LAP bioceramic slurry for subsequent VPP printing based on stability experiments and viscosity characterization results. The curing parameters of the photosensitive bioceramic slurry and the degassing sintering process were studied to ensure the quality of the ceramic green bodies. Then, we characterized the effects of different sintering temperatures (1150°C, 1200°C, 1250°C) on the crystalline phase composition, microstructure, and mechanical properties of the LAP bioceramic. The research showed that the densification and compressive strength of the LAP bioceramic sintered at 1250°C reached 2.51 g/cm3 and 15 Mpa, respectively. Finally, the bioceramic scaffolds with different sintering temperatures were co-cultured with rat bone marrow mesenchymal stem cells to detect biocompatibility. The results showed that the three groups of scaffolds enhanced cell proliferation, adhesion, and osteogenic capacity. In conclusion, the LAP bone scaffolds by VPP presented the potential for bone repair.

Effects of Al variations on the microstructure and mechanical properties of laser-cladding AlxNbMo0.5Ti1.5Ta0.5Cr0.5 refractory high-entropy alloy coatings

Lightweight refractory high-entropy alloy coatings (RHEAcs) of AlXNbMo0.5Ti1.5Ta0.5Cr0.5 (where x = 0, 0.1, 0.2, and 0.3) were fabricated on 316L stainless steel surface by pre-placed powder laser cladding (LC) technology. The incorporation of Al element significantly enhanced the forming quality of coatings, resulting in nearly defect-free coatings with a thickness of 1.2-1.4mm. Microstructural analysis revealed that the coatings were primarily composed of body-centered cubic (BCC) solid solution and C15-Laves phase. Due to the influence of a single brittle BCC phase, the Al-free coating exhibited high strength and brittleness, leading to numerous defects caused by thermal stress. The introduction of Al element refined the microstructure and facilitated the formation of Laves phases at grain boundaries, thereby alleviating stress to a certain extent. Consequently, the microhardness of the RHEAcs was significantly higher than that of the substrate, with the Al-free coating achieving the highest microhardness of 1250 HV, which was 5.89 times that of the substrate. Wear resistance results indicated that, prior to annealing, RHEAcs with varying Al content outperformed 316L stainless steel. Post-annealing, the coatings exhibited significantly lower friction coefficients compared with the annealed 316L substrate. The Al-free coating showed significant accumulation of abrasive particles, leading to severe abrasive and oxidative wear. Conversely, post-annealing oxidation induced the formation of dense and directional oxide accumulation, resulting in a notable improvement in wear resistance. Finally, the underlying strengthening mechanisms have been proposed and analyzed.

A Critical review on the performance and microstructural characteristics of materials fabricated through friction stir additive methods and deposition techniques

This review examines the distinctions between metallic alloys fabricated using friction stir techniques in additive manufacturing, focusing on friction stir additive manufacturing (FSAM) and additive friction stir deposition (AFSD) of aluminium, magnesium, and titanium alloys. The analysis emphasizes the microstructural characteristics and mechanical properties of these alloys. FSAM is noted for its ability to produce refined equiaxed grains, contributing to enhanced mechanical strength and structural integrity. In contrast, AFSD is characterized by its ability to achieve significant microstructural refinement, leading to improved hardness and corrosion resistance. However, challenges such as resolution limitations, mechanical stability issues in high-aspect-ratio structures, and the need for optimized post-processing persist. The study underscores the potential of FSAM and AFSD to advance additive manufacturing by addressing these challenges and optimizing process parameters for a wide range of engineering applications.

Effect of annealing on microstructure and mechanical properties for as-sintered Co-free Al1·8CrCuFeNi2 high entropy alloy

Effect of annealing on microstructure and mechanical properties for as-sintered Co-free Al1·8CrCuFeNi2 high entropy alloy

The microstructure, ablative resistance and mechanical properties of C/C-(Zr, V, Si)C composites after ablation

The microstructure, ablative resistance and mechanical properties of C/C-(Zr, V, Si)C composites after ablation

Structural damage and bubble evolution in SiC-ZrC composite irradiated with 500 keV He-ions at various temperatures

Ceramic composites with high temperature strengths and low neutron cross-sections are promising candidates for core materials in advanced nuclear systems. In present work, SiC-20 vol% ZrC composites were irradiated with 500 keV He-ions at 25, 500 and 800 °C to evaluate the effect of irradiation temperature on the structural damage and bubble evolution in ceramic composites. XRD and Raman spectra analysis give that the irradiation resulted in structural damages of both SiC and ZrC. TEM observations reveal the formation of helium bubbles and defect clusters after irradiation. Moreover, the occurrence of micro-cracks in ZrC grains and amorphization of SiC are observed for the samples irradiated at room temperature. Nanoindentation test showed that there is irradiation induced hardening or softening of the composites which depends on the irradiation temperature or fluence. The correlation between microstructural evolution and mechanical properties response is discussed.

Microstructural evolution and mechanical properties of Ti-5Al-3Mo-3Cr-1Zr-0.15Si alloy by annealing treatments

Microstructural evolution and mechanical properties of Ti-5Al-3Mo-3Cr-1Zr-0.15Si alloy by annealing treatments

Effect of Co content on microstructure and properties of TiCN-TiB2 cermets prepared by spark plasma sintering from a TiCN-B4C-Ti-Co system

Series of TiCN-TiB2 cermets were in situ prepared from the TiCN-B4C-Ti-Co system via spark plasma sintering (SPS). The effects of Co content on the densification, microstructure, mechanical properties, and wear resistance of TiCN-TiB2 cermets were investigated. The results showed that the Co addition had little effect on the phase composition of the sintered cermets, but had significant influences on the densification, microstructure and mechanical properties. Appropriate addition of metal Co could enhance densification and promote the grain growth of ceramic phases, but excessive addition resulted in a decrease in hardness and wear resistance. When the Co content was 10 wt.%, the cermet obtained the optimal comprehensive performance (a hardness of 1757 HV and a fracture toughness of 7.02 MPa•m1/2). Meanwhile, the cermets with 10 wt.% Co addition exhibited optimum wear resistance properties due to a good combination of hardness and toughness and moderate grain size. In addition, the formation process and strengthening mechanism in present system were discussed in detail. Results from this work could provide valuable references for the fabrication of TiB2 reinforced TiCN-based cermets.

Microstructure and properties of superelastic Ti-18Zr-15Nb alloy subjected to combination of moderate/severe cold drawing and post-deformation annealing

Ti-18Zr-15Nb (at. %) shape memory alloy was subjected to a thermomechanical treatment (TMT), combining cold drawing (CD) with moderate (e = 0.5/1.1), and severe (e = 1.9/3.3) true strains, and post-deformation annealing (PDA) at 500-600 °C to fabricate a wire for medical application. The phase composition, microstructure, crystallographic texture, mechanical and functional properties were studied. The combination of cold drawing with true strain e = 0.5 and PDA at 550 °C for 5min showed remnants of the original deformed grains, inside of which there is apparently a polygonized substructure, and a partially recrystallized structure of β-phase with a low amount of α-phase (grain size of D≈8 μm). With an increase in true strain, annealing temperature and holding time, a fully recrystallized structure and grain growth were observed. After TMT including the moderate cold drawing, a crystallographic texture with preferable orientation in the <101>β direction was formed. As true strain increases to e = 1.9/3.3, the preferable orientation changes to the <210>β direction; the intensity of this crystallographic texture increases as the true strain increases. Maximum difference between the dislocation and transformation yield stresses was observed after CD with true strain e = 1.1 and PDA at 550 °C for 30min (Δσ ≈ 405MPa). Elongation to failure about 20% was observed after CD with a true strain of e = 0.5 and PDА at 600 °C for 30min (D≈15 μm). During superelastic cyclic testing with 4% applied strain after CD (e = 1.9-3.3) and PDA at 550 °C for 5-15min (D≈1-3 μm) the alloy exhibits high values of superelastic (εrse ≈ 1,8-2,1%) and total elastic+superelastic (εrel+se ≈ 3,3-3,5%) recovery strains as well as sufficient maximum tensile stress (σmax ≈ 441-472MPa), and accumulated residual strain (εacc ≈ 0.4-0.7%).

Development of the magnetodielectric properties of BaTiO3-CoFe2O4 multiferroic composites

The lead-free x CoFe2O4 – (1-x) BaTiO3 (x= 0, 0.075, 0.15, 0.225, and 1) composites have been prepared via the solid-state process. The composites' microstructure, dielectric, ferroelectric, ferromagnetic, and magnetodielectric (MD) properties were investigated. Notably, XRD analysis indicates a decrease in the tetragonality factor (cT/aT) of the BTO phase, accompanied by an expansion of the unit cell as x increases from 7.5 to 22.5 wt.%. According to the FESEM images, the CoFe2O4 (CFO) grains are uniformly distributed in the matrix with the formation of no impurity phase. The optimal dielectric properties (dielectric constant (εr) ∼ 2018 and dielectric loss factor (tan δ) ∼ 0.16) and ferroelectric characteristics (saturation polarization (PS) ∼ 12 μC/cm2 and remnant polarization (Pr) ∼ 10 μC/cm2) are achieved at x=7.5 wt.%, attributed to the minimal presence of the non-ferroelectric CFO phase. By increasing the ferrite content (up to 22.5 wt.%), the ferroelectric properties of the samples showed a gradual diminution. Also, from x=7.5 to 22.5 wt.%, a sharp increase in the saturation magnetization (from 3.75 to 11.3 emu/g) and remnant magnetization (from 0.93 to 2.35 emu/g) values was observed, while the coercivity diminished from 475.8 to ∼ 272 Oe. The simultaneous observation of two ferroic characteristic hysteresis loops validated the multiferroicity of the composites (x=7.5, 15, and 22.5 wt.%). The maximum MD constant (4.68%) was measured for x=22.5 wt.% composite at the applied magnetic field of 7 kOe.

Investigation of the microstructure, electrical and mechanical properties of Al-CNTs-B4C composite prepared by double-step stir casting for power transmission conductor

Abstract Monolithic aluminium alloy is a modern engineering material that is in high demand owing to its excellent performance and versatility. It has a high electrical conductivity, low density, high strength- to- weight ratio, and high resistance to corrosion. However, it lacks adequate resistance to creep, fatigue, stable microstructure, and strength at elevated temperatures. To overcome these deficiencies, aluminium matrix composites are developed. This work focuses on an experimental investigation of the microstructure, mechanical strength, and electrical conductivity of Al-CNTs-B4C composite consolidated by a double-step stir casting technique. An x-ray diffractometer, transmission electron microscopy, and a field-emission scanning electron microscope fitted with energy dispersive x-ray spectroscopy were used to characterize the start-up powders and the cast samples. A Brinell tester was used to measure the microhardness of the cast samples. A four-point probe meter was used to determine the electrical conductivity. The microstructural results revealed formation of Al4C3 and Al3BC intermetallics, B4C phase and amorphous carbon precipitate. Marginally improved electrical conductivity of 33.33 × 107 S m−1 (65.1% IACS) was obtained with Al-5CNTs-15B4C, together with high microhardness of 725.72 MPa. The microhardness improved by 94.7% over monolithic pure Al. The double-step stir casting enhanced the homogenous dispersion of the reinforcements. The improvements in the mechanical properties and electrical conductivity were attributed to the synergy between B4C and CNTs which induced Orowan looping, load transfer effect, plastic deformation and dislocation pinning in the composite. It is recommended that this composite will perform creditably in power transmission.

Effect of mechanical milling time on powder characteristic, microstructure, and mechanical properties of AA2024/B4C/GNPs hybrid nanocomposites

In this study, hybrid nanocomposites consisting of an AA2024 matrix reinforced with 1 wt% B4C nanoparticles and 1 wt% GNPs were produced using a powder metallurgy method assisted by mechanical milling. This study aimed to systematically investigate the effect of grinding time on powder characteristics (particle size, microhardness, and morphology) as well as microstructure, densification, and mechanical performance to optimize processing conditions for superior material properties. Microstructural characterization of powders and bulk samples were carried out using a SEM device equipped with EDS. The results indicate that with increasing milling time, the particle size significantly decreased, while the particle hardness increased substantially. Additionally, the sample milled for 8 h achieved the highest relative density among the hybrid nanocomposites, reaching a value of 95.3 %. Mechanical tests revealed that after 8 h of milling, the hardness and tensile strength reached peak values of 164 HB and 314 MPa, corresponding to increases of 56 % in hardness and 43 % in tensile strength compared to the unreinforced alloy. The analysis results confirm that the optimal properties were obtained after 8 h under all conditions.

Effect of heat treatment on the microstructure and corrosion properties of plasma wire arc additive manufactured Mg-Gd-Y-Zr alloy

Effect of heat treatment on the microstructure and corrosion properties of plasma wire arc additive manufactured Mg-Gd-Y-Zr alloy

Optimization of microstructure and multiferroic properties of BFO–BTO/BaM composites through cold sintering and post-annealing

Optimization of microstructure and multiferroic properties of BFO–BTO/BaM composites through cold sintering and post-annealing

Study of strength-ductility and anisotropic behavior of Mg-Gd-Y-Zn-Zr alloy prepared by Equal channel double angular pressing

In the present work, the Mg-Gd-Y-Zn-Zr alloy was processed by Equal channel double angular pressing (ECDAP). The evolution of microstructure and mechanical properties are systematically investigated. The results demonstrate that the strength and ductility after ECDAP can be simultaneously enhanced, which is due to the generation of dynamic recrystallization and unique basal texture with dispersive circular distribution. The anisotropy behavior is also evaluated by the compression testing along different direction. After ECDAP for 4 passes, the anisotropy degree is effectively decreased compared with the sample after ECDAP for 1 pass. Moreover, the deformation behavior during ECDAP process is determined by prismatic slip.

Synthesis of nano-diamond modified Ti3C2Tx MXene heterostructure for enhanced electromagnetic wave absorption

The highly efficient electromagnetic wave (EMW) absorption materials are considered a promising approach to combatting electromagnetic radiation pollution. We synthesized a novel heterostructure 2D Ti3C2Tx MXene composite film modified by 0D nano-diamond (ND) particles using simple mechanical stirring and a vacuum filtration method. Subsequently, we investigated its microstructure and EMW absorption properties. The ND modification not only regulated the impedance matching of the composite films but also enhanced the diversity of EMW losses, demonstrating excellent microwave absorption performance. With a 40 wt% ND content, the minimum reflection loss (RLmin) of the films reached −43.0 dB, corresponding to a film thickness of 2.5 mm. This study explored a novel and promising microwave absorption film, expanding the application of diamond in microwave absorption, and addressing the theoretical gap in diamond-enhanced MXene microwave absorption performance.

Effects of pre-tension on the microstructural stability and mechanical properties of a near-alpha high temperature titanium alloy

Effects of pre-tension on the microstructural stability and mechanical properties of a near-alpha high temperature titanium alloy

Effect of γ-irradiation combined with enzymatic modification on the physicochemical properties of defatted rice bran dietary fiber

This study comprehensively examines how combining γ-irradiation and enzymatic modification influences the microstructure and physicochemical properties of dietary fiber (DF) obtained from defatted rice bran. The resulting yields of soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were measured at 13.38 ± 0.40 g/100 g and 52.19 ± 0.97 g/100 g, respectively. The modifications led to a diminish in particle size, an increase in specific surface area, and an improvement in water-holding capacity, oil-holding capacity, swelling capacity, glucose adsorption capacity, and cholesterol adsorption capacity. Furthermore, the modified DF exhibited enhanced anti-digestive properties and probiotic activity. Cluster and principal component analysis results revealed that the modified SDF exhibited superior functional properties. Correlation analysis indicated a noticeable relationship between the monosaccharide composition of DF and its functional characteristics. These findings suggest that γ-irradiation combined with enzymatic modification represents a viable approach for enhancing the quality of rice bran DF.