Journal of Materials Engineering and Performance最新文献

Lightweight and durable materials like Al-Ni alloys are needed for applications demanding high-strength-to-weight ratios, such as in the automotive and aerospace industries. This study investigated the microstructural evolution and mechanical properties of stir cast Al-Ni alloys (5-7 wt.% Ni) and optimized their dry sliding wear behavior using the Taguchi-Gray relational analysis. Increasing nickel content led to a higher volume fraction of the hard Al₃Ni intermetallic phase, confirmed by XRD and EDS analyses. This resulted in a 2.6% increase in ultimate tensile strength (Al-7 wt.% Ni compared to Al-5 wt.% Ni). Increasing the nickel content in the stir cast Al-Ni alloys resulted in enhanced hardness, with the Al-7 wt.% Ni alloy exhibiting a 3.37% higher hardness than the Al-5 wt.% Ni alloy, primarily attributed to the formation of hard Al₃Ni intermetallics and solid solution strengthening. The density also slightly increased with higher Ni content due to the substitution of Al atoms with heavier Ni atoms. Sliding distance and applied load were identified as the most significant factors affecting wear, while nickel content had a less dominant influence. Multi-objective optimization resulted in a 14.1% improvement in dry sliding performance, with the gray relational grade improving by 86.8% from the initial to the optimal wear test settings. This study highlights the positive correlation between microstructural features, mechanical properties, and wear resistance in Al-Ni alloys.

A series of problems, such as instability and sandwich shear failure, can quickly occur on brazed honeycomb aluminum panel, leading to difficulty during its processing and forming. Therefore, to obtain the best process parameters under different conditions, a combination of finite element simulation and experiment to study the compression performance of honeycomb aluminum panels at room temperature and high temperature was used in this project, which provides an effective technical way for compression of honeycomb aluminum panels. It was found that the outer stress of the honeycomb aluminum panel was more significant than the inner stress during flat pressing, and the strain value at the height of 1/3 after compression was about four times that of other positions. Through the flat compression experiment under different strain rates, it was found that with the decrease in strain rate, the maximum compressive stress that can be withheld increases, and the corresponding compression amount decreases. By studying the stress distribution on the flat side pressure at different temperatures, it was found that the rise in temperature leads to a more uniform stress distribution, which affects the final deformation.

Understanding the thermal response of materials with defects under microwave irradiation is critical for various applications, including electronics, materials science, and energy conversion. This study investigates microwave energy interaction with carbon defect-induced 3C-SiC by employing non-equilibrium molecular dynamics to gain insights into the molecular level heating of 3C-SiC in the presence of carbon defects. Simulation studies were conducted to explore the effects of microwave irradiation at varying electric field strengths and frequencies. The results demonstrated that introducing C-vacancies within the 3C-SiC system significantly improved microwave absorption, enabling the material to reach the melting point more rapidly than pure 3C-SiC. Moreover, this simulation study revealed that C-vacancies facilitated higher atomic diffusivity within the system. At 2.0% C-vacancy concentration, the 3C-SiC system exhibits 492, 260, and 77.8% higher diffusivity than 0.5, 1.5, and 1.5% C-vacancy concentration, respectively, at an electric field strength of 0.5 V/Å and frequency of 300 GHz. Pair correlation function study revealed a reduction in crystallinity by approximately 60 for 0.5% C-vacancy concentration during microwave irradiation. Pair correlation function analysis further confirmed that the accelerated solid-to-liquid phase transition occurred with increasing C-vacancy concentration and microwave exposure time.

With the rapid advancement of industrial applications, the demand for high-performance copper alloys has significantly increased. Copper alloys combining high strength, superior electrical conductivity, and excellent wear resistance are urgently required in modern industries. To balance the mechanical properties and electrical conductivity of the hot-rolled Cu-1.0Cr-0.1Zr alloy, the effects of annealing and aging treatments on its comprehensive performance were systematically investigated. The results demonstrate that the alloy rolled at 780 °C (with a rolling reduction of 90%) exhibits remarkable improvement in overall properties after short-time annealing. Microstructural and mechanical analyses reveal that increasing the annealing temperature promotes grain regrowth within the copper matrix and enhances recrystallization, thereby strengthening the alloy’s performance. Furthermore, subsequent aging treatment reduces dislocation density and defects in the alloy while diminishing electron scattering barriers, leading to optimized electrical conductivity.

Additive manufacturing (AM) enabled the production of complicated lattice architectures which found growing applications in biomedical implants because of their light weight, mechanical compliance, and potential to enhance osseointegration. Despite the advantages of lattice structures fabricated by additive manufacturing (AM) for biomedical implants, the improvement of bioactive coatings on these complex geometries remains an imposing challenge. Specifically, lattice topology's influence on coating quality and uniformity is poorly understood, leading to a knowledge gap that prevents achieving consistent and effective bioactive coatings on AM lattice structures. Furthermore, there is a need to perform research in optimizing these coatings for long-term bioactivity and durability in complex lattice geometries. This study is geared toward addressing this deficiency because it evaluates the effect of lattice topology on hydroxyapatite–chitosan composite coatings developed on laser powder bed fusion-manufactured (LPBF) Ti6Al4V lattice structures. The significance of EPD process parameters and the effect of lattice topology (dodecahedron, octahedron and star) on such parameter optimization were examined. The optimum EPD conditions resulted in more surface-covered and stable films. In the study where a total of 21 recipes were tested, quantitatively, the dodecahedron lattice structure in recipe 13 showed the highest cell viability of 92.7% and the lowest viability was achieved for the octahedron lattice structure in recipe 11 at 68.8%.. The results confirmed that lattice topology has an important influence on coating uniformity and morphology. The optimized EPD conditions produced coatings with improved surface coverage and stability.

Rare earth microalloying effectively enhances magnesium alloy performance. This study designed Mg-2Y-1Al (WA21) and its Ca/Mn-modified variants (0.3Ca-0.7Mn, 0.5Ca-0.5Mn, 0.7Ca-0.3Mn) to investigate their 200 °C compressive behavior. Thermal compression tests (0.001 s⁻¹, ε = 0.3) revealed that trace Ca/Mn additions significantly improved compressive yield strength (CYS) and ultimate compressive strength. EBSD analysis demonstrated remarkable grain refinement, with WAXM210505 achieving a 50% reduction in average grain size (20.32 μm) compared to WA21. In-grain misorientation axis (IGMA) and Schmidt factor analyses indicated that pyramidal <c  + a  > slip dominated deformation across all alloys, accompanied by limited prismatic <a  > slip. Discontinuous dynamic recrystallization (DDRX) was identified as the primary DRX mechanism, with Ca/Mn additions promoting DRX development and texture weakening. The refined microstructure and optimized slip activity collectively contributed to enhanced high-temperature strength. These findings elucidate the role of Ca/Mn ratio in balancing slip system activation and DRX kinetics, providing critical insights for designing heat-resistant Mg-Y-Al alloys tailored for compressive load applications, providing new insights for the development of low-cost magnesium alloys with excellent service performance.

This study focuses on the modeling and optimization of wire electric discharge machining (WEDM) parameters for Nimonic-C263 superalloy using artificial neural networks and response surface methodology (RSM). Due to its exceptional mechanical properties and corrosion resistance, Nimonic-C263, a superalloy based on nickel with high strength, finds widespread application in the aerospace and power generation industries. However, its machinability remains challenging due to its high hardness and toughness. This study considers the input parameters of spark energy (SE), spark frequency (SF), and peak current (PC). The evaluation of machining performance is based on cutting rate (CR) and surface roughness (SR). Experimental trials utilize the Box–Behnken design, with the collected data employed to construct predictive models through RSM-based regression analysis and ANN modeling. The ANN model is trained to utilize a feed-forward backpropagation algorithm and is validated through statistical performance measures, including mean squared error and coefficient of determination (R²), to ensure high prediction accuracy. Comparative analysis reveals that the ANN model demonstrates superior predictive capability over RSM due to its ability to capture complex nonlinear regression equations between input parameters and machining responses. The optimized parameters significantly enhance machining performance, making WEDM a viable method for precision machining of Nimonic-C263. The spark energy directly influences the thermal energy necessary for the WEDM process. The maximum CR 8.985 mm/min was attained SE: 9 J, SF: 24 Hz, and PC: 4 A with a moderate SR of 2.045 µm. Conversely, SE: 8 J, SF: 26 Hz, and PC: 3 A yielded a cutting rate of 4.521 mm/min with a surface roughness of 1.867 µm. The findings of this research provide a robust framework for optimizing WEDM of nickel-based superalloys using AI-driven modeling techniques, contributing to improved efficiency and surface integrity in advanced manufacturing applications.

This study investigated the impact of die bearing geometry on the surface cracking behavior, of a high strength AA6xxx alloy. Experimental and numerical methods were employed, along with differential scanning calorimetry tests to determine the material’s solidus temperature. Four different die geometries were employed in both the extrusion trial and the simulation. Extrusion trials were conducted for each die geometry over a range of extrusion speeds with the resulting surface defects being examined using SEM. The findings indicate that die bearing geometry significantly affects surface morphology and crack occurrence. Choked dies enabled crack-free extrusion at higher speeds, particularly a 12 mm choked bearing with a 1° angle, outperforming a 25 mm flat bearing and zero-bearing die. The 35 mm choked bearing achieved crack-free extrusion even at maximum extrusion speed, yielding smoother surfaces than the other dies. Numerical simulations demonstrated the differences in stress states using different die bearing geometries, showing that the choked bearings alter the stress state at the die corner to cause a transition from high tensile stress to lower tensile or compressive stress. The extrusion limit diagrams for different die bearings were also constructed based on the extrusion trial data to provide guidance for choosing appropriate extrusion parameters for future studies. This study adds a valuable contribution to the existing literature by shedding light on the role of die bearing geometry in controlling surface morphology and surface crack formation, providing important insights that can be used to optimize the extrusion process.

A medium manganese steel of nominal composition 0.063C-14.91Mn-4.38Ni-2.05Al-0.82W-2.18Mo-1.77Cu-1.72Si-0.09Nb-0.11V-0.0007B (composition in wt.%) is chosen for the study. The steel produced by induction melting was forged and hot rolled for securing a homogeneous structure. The hot rolled strip of 8 mm thickness was used for further study. The steel strips were heat treated in accordance with predesigned schedules, as detailed in experimental section. Characterization of heat-treated steels (quenched and aged) in respect of its structure and mechanical properties was performed with the aid of x-ray diffraction , scanning electron microscope, electron back scatter diffraction and transmission electron microscopy studies for microstructure and fractography; universal testing machine was employed for mechanical property evaluation. It was observed that the microstructure of the steel is mostly composed of twinned austenite with dispersed molybdenum carbides. Occasional presence of martensite could be noticed too. Moreover, it was observed that upon ageing at 600 °C for 40 h, the ice water quenched steel could achieve attractive combination of strength and toughness, such as 950 MPa UTS at 39% percent elongation. The yield tensile ratio of 0.56 unveil the potential of the steel for automotive application presumably for its potent deep drawability.

This study presents a comprehensive evaluation of the abrasion and corrosion resistance of AISI316 vanadium carbide (VC) composite claddings developed on 080M40 steel using the WAAM-CMT technique for enhancing the longevity of agricultural tools. Claddings reinforced with 10% and 20% VC exhibited notable improvements in mechanical and chemical performance. The surface microhardness increased from 233 HV (uncladded substrate) to 362 HV (AISI316), 408 HV (10% VC), and 427 HV (20% VC), marking an overall enhancement of ~ 83%. Dry sand abrasion tests showed a significant 42.8% reduction in mass loss for the ASV20 cladding compared to the base material, attributed to the formation of a hard, wear-resistant load-bearing structure by VC particles. Corrosion resistance, assessed via salt spray testing, improved markedly, with ASV20 achieving a corrosion rate of 0.00028 mm/year approximately 86% lower than the substrate’s 0.00204 mm/year. SEM analysis confirmed uniform VC dispersion in the AISI316 matrix, which acted as effective barriers against abrasive wear and chloride ion ingress. These findings highlight the superior performance of VC-reinforced AISI316 claddings for soil-engaging components under harsh environmental conditions.