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In recent years, biodegradable metallic materials have played an important role in biomedical applications. However, as typical for the metal materials, their structure, general properties, preparation technology and biocompatibility are hard to change. Furthermore, biodegradable metals are susceptible to excessive degradation and subsequent disruption of their mechanical integrity; this phenomenon limits the utility of these biomaterials. Therefore, the use of degradable metals, as the base material to prepare metal matrix composite materials, it is an excellent alternative to solve the problems above described. Biodegradable metals can thus be successfully combined with other materials to form biodegradable metallic matrix composites for biomedical applications and functions. The present article describes the processing methods currently available to design biodegradable metal matrix composites for biomedical applications and provides an overview of the current existing biodegradable metal systems. At the end, the manuscript presents and discusses the challenges and future research directions for development of biodegradable metallic matrix composites for biomedical purposes.

This study provides a novel approach to fabricating Al/C composites using laser powder bed fusion (LPBF) for a wide range of structural applications utilizing Al-matrix composites in additive manufacturing. We investigated the effects of LPBF on the fabrication of aluminum/multiwalled carbon nanotube (Al/MWCNT) composites under 25 different conditions, using varying laser power levels and scan speeds. The microstructures and mechanical properties of the specimens, such as elastic modulus and nanohardness, were analyzed, and trends were identified. We observed favorable sintering behavior under laser conditions with low energy density, which verified the suitability of Al/MWCNT composites for a fabrication process using LPBF. The size and number of pores increased in specimens produced under high energy density conditions, suggesting that they are more influenced by laser power than scan speed. Similarly, the elastic modulus of a specimen was also more affected by laser power than scan speed. In contrast, scan speed had a greater influence on the final nanohardness. Depending on the laser power used, we observed a difference in the crystallographic orientation of the specimens by a laser power during LPBF. When energy density is high, texture development of all samples tended to be more pronounced.

Industries are currently concentrating on materials that can replace monolithic metals and alloys. The transition from monolithic to advanced materials has resulted in the development novel materials. These materials have better properties than traditional ones, such as high-temperature resistance, increased specific stiffness, increased specific strength, and other mechanical and tribological properties. Metal matrix composites (MMCs) are currently gaining more attention as a critical engineering material due to their superior characteristics over monolithic materials. These MMCs have wide applications in the automotive, aerospace, defense, and marine industries. This makes them worthy of further investigation as potential alternative materials. This paper attempts to review the current advances in producing hybrid metal matrix composites (HMMCs). In addition, the article covers the impact of matrix material selection, reinforcement, and processing techniques on the production of metal matrix composites.

Abstract The excellent mechanical and lubricant property make graphene an ideal enhanced phase for high-performance composites. Graphene metal matrix composites with good structural mechanical and tribological properties have a wide range of applications in aerospace, automotive, electronics, and biomedical fields. However, some problems exist in preparing high-performance metal matrix composites including poor wettability between graphene and metal matrix, and weak interfacial bonding strength. Efficient methods for preparing graphene metal matrix parts with high performance still need to be further developed. Meanwhile, the study of the tribological behavior of graphene-reinforced metal matrix composites is rather limited, and the poor wear resistance is a limiting factor for a wide range of applications. In this paper, the properties of graphene are reviewed and the applications of graphene are discussed with specific examples. The methods of preparing high-performance metal matrix composites are reviewed and the main challenges were analyzed, and the mechanical and tribological properties of graphene metal matrix composites are discussed with emphasis. The research directions and application trends of graphene metal matrix composites have been prospected.

The presented study investigates the effects of weight percentages of boron carbide reinforcement on the wear properties of aluminum alloy composites. Composites were fabricated via ball milling and the hot extrusion process. During the fabrication of composites, B4C content was varied (0, 5, and 10 wt.%), as well as milling time (0, 10, and 20 h). Microstructural observations with SEM microscopy showed that with an increase in milling time, the distribution of B4C particles is more homogeneous without agglomerates, and that an increase in wt.% of B4C results in a more uniform distribution with distinct grain boundaries. Taguchi and ANOVA analyses are applied in order to investigate how parameters like particle content of B4C, normal load, and milling time affect the wear properties of AA2024-based composites. The ANOVA results showed that the most influential parameters on wear loss and coefficient of friction were the content of B4C with 51.35% and the normal load with 45.54%, respectively. An artificial neural network was applied for the prediction of wear loss and the coefficient of friction. Two separate networks were developed, both having an architecture of 3-10-1 and a tansig activation function. By comparing the predicted values with the experimental data, it was demonstrated that the well-trained feed-forward-back propagation ANN model is a powerful tool for predicting the wear behavior of Al2024-B4C composites. The developed models can be used for predicting the properties of Al2024-B4C composite powders produced with different reinforcement ratios and milling times.

In recent years, metal matrix composite (MMCs) have been receiving worldwide attention on account of their superior strength-to-weight ratio and stiffness. Among the several classes of composite materials, Aluminium matrix ceramic reinforcement composites have attracted increasing attention due to their unique properties such as better specific strength, specific stiffness, wear resistance, excellent corrosion resistance, high elastic modulus and light weight. The aim of the present investigation is to optimize the dry sliding wear parameters of Aluminum LM25 matrix reinforced with silicon carbide (SiC) (5 wt.%) and Copper (Cu) (3 wt.%) using Taguchi based grey relational analysis. In this work, the composite is prepared using stir casting method. The specimens are prepared according to ASTM standard. Using pin-on-disc apparatus, wear tests are conducted as per Taguchi's L9 orthogonal array and optimum wear parameters are identified with an objective to minimise the wear rate and coefficient of friction based on the grey relational grade. The effect of parameters on the wear rate and coefficient of friction was determined using Analysis of variance (ANOVA). Finally, the experimental results were verified using confirmation tests and the SEM analysis was carried out to study the wear mechanism.

Among several kinds of metal matrix composite materials (MMCs), such as silicon-based reinforced aluminum matrix (SiCp/Al) composites have become the most valuable composite material due to their various applications in industries, sports equipment, electrons, and automotive. Due to the presence of hard ceramic reinforcements, the SiCp/Al composite is considered a difficult-to-cut material, which leads to significant hindrances in machining operations together with increased tool wear, cutting force, and degradation of machined surface quality. The present review is focused on the recent advancements in turning process of metal matrix composites. An attempt is made to comprehensively analyze and identify the influencing factors on the machinability of metal matrix composites (MMCs). The main purpose of this review is to cover the topics such as the recent trends in turning and hybrid turning processes of MMCs, tool wear and its mechanisms, tool selection, the effect of cutting parameters, surface integrity, SiCp/Al composite properties and reinforcement effect, chip formation mechanisms, and different modeling approaches used in particle-reinforced MMCs machining process. Finally, some research gaps and future directions are suggested that could lead to efficient machining of particle-reinforced MMCs.

In response to the growing demand for high-strength and high-toughness materials in industries such as aerospace and automotive, there is a need for metal matrix composites (MMCs) that can simultaneously increase strength and toughness. The mechanical properties of MMCs depend not only on the content of reinforcing elements, but also on the architecture of the composite (shape, size, and spatial distribution). This paper focuses on the design configurations of MMCs, which include both the configurations resulting from the reinforcements and the inherent heterogeneity of the matrix itself. Such high-performance MMCs exhibit excellent mechanical properties, such as high strength, plasticity, and fracture toughness. These properties, which are not present in conventional homogeneous materials, are mainly due to the synergistic effects resulting from the interactions between the internal components, including stress–strain gradients, geometrically necessary dislocations, and unique interfacial behavior. Among them, aluminum matrix composites (AMCs) are of particular importance due to their potential for weight reduction and performance enhancement in aerospace, electronics, and electric vehicles. However, the challenge lies in the inverse relationship between strength and toughness, which hinders the widespread use and large-scale development of MMCs. Composite material design plays a critical role in simultaneously improving strength and toughness. This review examines the advantages of toughness, toughness mechanisms, toughness distribution properties, and structural parameters in the development of composite structures. The development of synthetic composites with homogeneous structural designs inspired by biological composites such as bone offers insights into achieving exceptional strength and toughness in lightweight structures. In addition, understanding fracture behavior and toughness mechanisms in heterogeneous nanostructures is critical to advancing the field of metal matrix composites. The future development direction of architectural composites and the design of the reinforcement and toughness of metal matrix composites based on energy dissipation theory are also proposed. In conclusion, the design of composite architectures holds enormous potential for the development of composites with excellent strength and toughness to meet the requirements of lightweight structures in various industries.

High-chromium white cast-iron specimens locally reinforced with TiC–metal matrix composites were successfully produced via an in situ technique based on combustion synthesis. Powder mixtures of Ti, Al, and graphite were prepared and compressed to fabricate green powder compacts that were inserted into the mold cavity before the casting. The heat of the molten iron causes the ignition of the combustion reaction of the reactant powders, resulting in the formation of the TiC by self-propagating high-temperature synthesis. The microstructure of the resultant composites and the bonding interfaces was characterized by scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The microstructural results showed a good adhesion of the composite, suggesting an effective infiltration of the metal into the inserted compact, yet a non-homogeneous distribution of the TiC in the martensite matrix was observed. Based on the results, the in situ synthesis appears to be a great potential technique for industrial applications.

The Hugoniot elastic limit and spall strength were measured for a heat-resistant metal-matrix composite Inconel 625–5%NiTi–TiB2 alloy additive manufactured (AM) by direct laser deposition. The strength characteristics of the alloy were obtained from the analysis of the complete wave profiles recorded with a VISAR laser Doppler velocimeter during shock-wave loading of the samples. The samples were loaded using a PP50 pneumatic gun or ad hoc explosive devices along and across the material deposition direction in order to determine the strength anisotropy of the AM alloy under study. The maximum shock compression pressure was ~7 GPa, and the strain rate under tension before spalling varied in the range of 105–106 s–1. Kinetic dependencies of elastic/plastic transition and critical fracture stresses vs. loading conditions were plotted. It was shown that the Hugoniot elastic limit of the alloy under study decreases as the shock wave travels into the sample, while the spall strength increases as the material’s strain rate increases at the moment of spall fracture. A comparison of the strength characteristics of the Inconel 625–NiTi–TiB2 composite alloy with the original Inconel 625 alloy has shown that an addition of 5% of powder based on NiTi-TiB2 leads to a decrease in its elastic limit and critical fracture stresses upon spalling by more than 10%. The alloy under study demonstrates anisotropy of strength properties relative to the material deposition direction.