Advanced Engineering Materials最新文献

In this article, a method for preparing surface texture of polycrystalline diamond compact (PDC) cutter based on nanosecond laser direct is reported. The relationship between the structure of the surface texture with the laser power, scanning speed, and processing cycle of the nanosecond laser is systematically investigated. By changing the laser power, scanning speed, and the number of processing cycle, different nanosecond laser energies are obtained for processing PDC cutter, and the nanosecond laser parameters are precisely changed to achieve the purpose of laser modification and ablation. By controlling the parameters of nanosecond laser processing, micrometer-scale surface texture on PDC cutter are realized. The surface morphology of the resulting preparation is analyzed. This study provids an experimental basis for the utilization of laser surface texturing technology to improve the performance of PDC cutter, and promotes the further research and development of drilling and machining tools.

In recent years, there has been a significant increase in research studies that include the fabrication and characterization of metal matrix composites (MMCs) with unique features. This comprehensive review delves into the evolution and current status of copper MMCs (Cu-MMCs) across various industrial sectors. Cu-MMCs have garnered attention due to their remarkable properties, which include excellent thermal and electrical conductivity, corrosion resistance, and wear resistance. This study explores the fabrication processes, and intricate connections between microstructure and properties of Cu-MMCs, which encompass ceramic and solid lubricants (SLs) reinforcements. The various types of reinforcement and fabrication methods are examined and highlighted advancements in designing compositions and optimizing microstructures during fabrication. Additionally, this study evaluates the friction and wear characteristics of self-lubricating hybrid composites, providing insights into effective lubrication ranges and overall tribological behavior patterns. This review highlights that Cu-MMCs demonstrate superior mechanical strength, wear resistance, and self-lubricating properties due to ceramics and SLs reinforcements. The mechanisms underlying this behavior involve the formation of a protective transfer layer during sliding and effective lubrication provided by SLs, which reduces direct contact and facilitates smoother interactions between the mating surfaces. The review culminates in an outlook on the prospects of Cu-MMCs, emphasizing the advantages conferred by their utilization.

Cold spray additive manufacturing (CSAM) is an attractive solid-state bonding technique due to its rapid manufacturing rate and the ability to avoid deleterious effects found in solidification-based additive manufacturing. Unfortunately, CSAM of steel components has been difficult to date to the high strength of the steel particles which resists deformation and creates interparticle porosity. Herein, it is found adding softer Cu powder particles to steel (SS316) powder and utilizing a heat treatment can decrease the porosity of the as-sprayed structure while increasing the mechanical properties. The mixture results in an increased sprayability of the structure, as the Cu particles preferentially fill the pores, increasing the density. The microstructural evolution of the SS316 and Cu particles at the particle interfaces and interiors is investigated and reveals that the materials undergo a heterogeneous deformation route which facilitates the densification of the CSAM structure. Through annealing these components, the tensile strength increases and the density increases further. Both materials undergo microstructural recovery along with selected interdiffusion of elements which improves the metallurgical bonding. It is demonstrated that the heterogeneous deposition and microstructural evolution between the dissimilar materials can improve the overall component properties.

Fully pearlitic steels are essential in many demanding structural applications due to their exceptional mechanical properties. These superior mechanical properties are attributed to the microstructural features of pearlite. However, investigating these steels via entirely experimental approaches is both time-consuming and costly, and only limited computational frameworks consider mesoscale plastic deformation of ferrite and cementite phases. This study introduces a comprehensive framework, integrating experimental and computational approaches, to scrutinize the impact of microstructural features on the mechanical behavior of pearlitic steels. Assigning specific plastic deformation and damage mechanics material models to the phases in the pearlite microstructure, along with calibrated parameters, enables a detailed investigation of the relationship between microstructure and mechanical behavior. Consistent with previous findings, the results show that a higher cementite volume fraction improves strength but diminishes failure strain, while increased interlamellar spacing correlates with reductions in both strength and fracture strain. Varying from random ferrite orientations to the [110] texture increases strength and reduces failure strain. These results validate the computational approach and reinforce the relationships between microstructural attributes and mechanical properties in pearlitic steels. Additionally, the study provides the basis for further computational material design that can enable tailored microstructures to achieve desired mechanical properties.

As the electronic industry continues to progress, there is a parallel increase in demand of materials for advanced electromagnetic interference (EMI) shielding. A hybrid approach is introduced by combining 3D geometrical structure with the integration of radar-absorbing materials (RAMs) to develop absorptive materials. Present study involves the fabrication of polylactic acid-based pyramidal honeycomb structures using 3D printing technology, followed by electroless silver plating and infusion with Fe₃O₄/epoxy composite. These developed structures/materials test comprehensive within frequency range of 8.2–12.4 GHz (X-band) using free space, and waveguide methods, focusing on both electromagnetic properties of RAM and EMI shielding performance of structures. Experimental results showcase exceptional potential of fabricated structures, demonstrating efficient EMI shielding up-to −55 dB, equivalent to 99.999% attenuation of EM waves. Particularly noteworthy is the dominant role of absorption as a primary shielding mechanism, as evidenced by more than 99% (−20 dB) absorption across the entire tested frequency spectrum.

Herein, the mechanical properties, oxidation behavior, and processing performance of the CoCrFeNiMn high-entropy alloy are investigated using multiple characterization methods. The alloy exhibits a yield stress of 462 MPa, an ultimate tensile strength of 1037 MPa, and a fracture strain of 31.8% at room temperature. Oxidation tests reveal that the oxide layer consists of an outermost oxide layer and a Cr₂O₃ layer at both 1000 and 1200 °C. The Cr₂O₃ layer formed at 1000 °C is dense and continuous, whereas it transitions from continuous to discontinuous as the temperature increases to 1200 °C. Localized peeling of the oxide layer is observed at 1200 °C due to the diminished protective effect of the Cr₂O₃ layer and the increased stress in the oxide layer caused by the formation of multiple complex oxides. Grinding experiments indicate that both the grinding force and surface roughness increase as the load increases. Additionally, energy-dispersive X-ray spectroscopy results show that the oxygen content of particles at a 120 N is higher than at 60 and 90 N, suggesting an elevated grinding temperature at 120 N, which leads to the formation of bonded convex particles.

This study investigates the influence of Pt addition on the oxidation behavior of a Cr₂O₃-forming superalloy. Inconel 718 (IN718) alloys with varying Pt content were prepared and subjected to isothermal oxidation tests. The results demonstrate that Pt significantly enhances the oxidation resistance of IN718, as evidenced by reduced weight gain, thinner oxide layers, and smaller oxide particles. Pt addition also increases the activation energy for both initial interface oxidation and ion diffusion during long-term oxidation. Furthermore, Pt promotes the formation of a Cr₂O₃ layer while suppressing the formation of other undesirable oxides, resulting in a more cohesive and stable oxide layer. The improved oxidation resistance is attributed to two key factors: during the initial oxidation stage, Pt, as a noble element, reduces the activity of the primary oxide-forming element Cr to oxidative environments, thereby lowering its susceptibility to initial oxidation at the metal–oxidant interface. During long-term oxidation, Pt preferentially substitutes for Ni in major phases such as γ-Ni(Cr,Fe) and γ′-Ni₃(Al,Ti), locally increasing the Cr composition. This promotes Cr oxidation, effectively suppressing the oxidation of Ni or Fe. These findings suggest that Pt addition is a promising approach for enhancing oxidation resistance in alloy design.

Given the increasing demand for energy-efficient and durable coatings, particularly in outdoor environments, this study investigates the development of lavender-shaded neodymium (Nd)-modified zinc aluminate pigment for thermal energy-saving applications. The results evidence the potential of incorporating this Nd-modified ZnAl₂O₄ pigment in zinc phosphate (ZP) coating to tune the morphology, microstructure, near-infrared (NIR) reflectance, thermal shielding, and corrosion resistance capability. The study provides a detailed elucidation of the mechanism of pigment particles’ incorporation into ZP coating, revealing enhanced nucleation and crystal size refinement, leading to denser coating with improved NIR reflectance and corrosion resistance, with aesthetic requirements potentially suitable for outdoor environments. Quantitative analysis reveals a maximum NIR reflectance of 93%, thermal shielding capacity with a temperature difference of 15.4 °C, and a more than threefold reduction in corrosion current density. The study underscores the potential of these coatings for energy-saving applications and outdoor use, highlighting their stability and effectiveness in various environmental conditions.

A high-strength metakaolin-based porous ceramics are fabricated using slurry-based material extrusion via optimizing four key process parameters, including nozzle internal diameter, height to diameter ratio, filling rate, and printing speed. The orthogonal experiments are used to adjust flexural strength and porosity, and the optimal process parameters are obtained by comprehensive scoring and range analysis methods. The predictive models of strength-parameters, porosity-parameters, and strength-porosity are established and validated. The results show that the optimal process parameters for high-strength and high-porosity ceramics are 0.51 mm nozzle internal diameter, 70% height to diameter ratio, 100% filling rate, and 15 mm s⁻¹ printing speed. The correctness and predictability of three predictive models are proved by two methods, which are the mutual validation and comparison between theoretical and actual values. And the error rates between theoretical and actual results are less than 7%. This work provides guidance for the rapid fabrication of ceramics with adjustable strength and porosity by material extrusion, and the established predictive models can pave the way for its wider application in the practice.

Composite Metal Foam Behavior

In article number 2401267, Afsaneh Rabiei and Aman Kaushik present a numerical approach to study the performance of composite metal foam (CMF) under compression using smooth particle hydrodynamics modeling of entrapped air inside the porosities of CMF. The numerical and experimental results agree well, opening room to further the fluid–solid interaction study of entrapped air inside the porosities of CMF to effectively predict its performance under a variety of loading scenarios.