Fabrication Of Metal Matrix Composites Research Articles

Comparative analysis of mechanical properties of SiC particle addition on Al6061/Ni and Al6061/Cr metal matrix composites

This research paper investigates the mechanical characteristics of Al6061/Nickel (Ni) and Al6061/Chromium (Cr) metal matrix composites (MMCs) with varying proportions of Ni and Cr by weight. The proportions of Ni and Cr range from 0% to 2.7% weight. Experimental results reveal that the optimum mechanical properties are achieved at 1.8% weight for Ni. Subsequently, SiC (silicon carbide) particles are added to Al6061/Ni MMCs at varying weight percentages (0%, 1%, 3%, 5%, and 7%) to evaluate their impact on performance. The study demonstrates that the combination of 1.8% Ni and 7% SiC in Al6061 exhibits the most favorable properties. Tensile test is carried out with ASTM D 3552 standard; Flexural strength is assessed through ASTM D790, Microhardness by ASTM E384, and Impact strength by ASTM D256. Overall, Al6061/Ni MMCs exhibit superior mechanical performance compared to Al6061/Cr MMCs, with Al6061/Cr MMCs excelling in elongation, flexural strength, and impact strength. This investigation confirms that the addition of nickel and chromium to the Al6061 alloy induces structural modifications that enhance its mechanical properties. The findings provide valuable insights for optimizing the design and fabrication of MMCs for various engineering applications.

Exploring tribological properties in the design and manufacturing of metal matrix composites: an investigation into the AL6061-SiC-fly ASH alloy fabricated via stir casting process

This study investigates a novel methodology to intricately craft a HAMMC and thoroughly examine its multifaceted mechanical and tribological characteristics. By combining silicon carbide (SiC) and fly ash as reinforcements, a unique identity is bestowed upon this hybrid composite, enhancing its structural integrity and functional attributes. Stir casting is the chosen methodology for fabricating this composite, favored for its economic viability and suitability for large-scale manufacturing. In this research, the emphasis is on developing a cost-effective composite that not only meets stringent economic considerations but also exhibits improved material properties. Within the realm of hybrid metal matrix composites, the well-regarded Al6061 takes on the role of the matrix material, while the synergistic inclusion of fly ash and SiC serves as reinforcing constituents. Three specimens with compostion 90% Al6061 + 5% SiC +5% Fly ash, 90% Al6061 + 10% SiC +6% Fly ash and 90% Al6061 + 15% SiC +7% Fly ash were fabricated. To unravel the intricacies of the fabricated Al6061 metal matrix composite, comprehensive tests are employed. These tests, including the Pin-on Disc test, Scratch test, Rockwell Hardness test, and Charpy Impact test, collectively work to unveil the nuanced tribological and mechanical behaviors encapsulated within this innovative alloy. The results indicated significant improvement in wear resistance in specimen comprising 78% Al6061 + 15% SiC +7% Fly Ash and volumetric loss found to have 0.96 g. Superior hardness characteristics and enhanced abrasion resistance found in 78% Al6061 + 15% SiC +7% Fly Ash than other two specimens. The highest impact strength exhibited in 90% Al 6,061 + 5% SiC +5% Fly ash specimen.

Recent Developments in the Use of High Pressures for the Production of Nanostructured Materials

The use of pressure to achieve superior properties in metals, especially for use in a range of weaponry, has a long history dating back to the artisans of ancient China and many parts of Asia. Nevertheless, scientific principles were not introduced until the classic experiments conducted by Nobel Laureate Professor Percy Bridgman at Harvard University almost 100 years ago and these experiments led directly to the development of metal processing through the procedure now known as high‐pressure torsion (HPT). This review provides a brief overview of the historical evolution of pressure as a convenient tool in metal‐working and then summarizes the major features associated with the processing of metals by HPT and, more recently, the torsional straining of stacked disks in HPT to produce a range of hybrid materials. Finally, there is a brief report on the development of the relatively new processing procedure of tube high‐pressure shearing (t‐HPS) which may be used for the fabrication of metal matrix composites.

Effect of friction stir processing parameters on mechanical properties of Al8011/CeO2/SiC/RHA metal matrix composite

ABSTRACT In this research work, the FSP route opted to fabricate the metal matrix composite (MMC) on the surface of an aluminium 8011 alloy sheet by incorporating different volumetric compositions of silicon carbide (SiC) and cerium oxide (CeO2) with a constant 5% volumetric composition of rice husk ash (RHA). The fabrication process was based on the L27 design of experiments. Taguchi-coupled grey relational analysis (GRA) was employed for process optimisation with four factors: tool rotation speed, tool travel speed, reinforcement volume, and tool type, each with three levels, while tensile strength and micro-hardness were taken as the response variables. The optimal parameter setting for fabrication of Al8011 MMC was 600 RPM of rotational speed (level 3), 20 mm/min travel speed (level 1), reinforcing volume% (level 2), and straight cylinder pin profile (level 1). The corresponding values of the optimised response variables were 181.91 MPa tensile strength and 139.09 Hv microhardness. The tensile strength and microhardness of base Al8011 were found to be 175.77 MPa and 92.72 Hv, respectively. Meanwhile, the microstructure of the optimal FSP-processed MMC was analyzed through the scanning electron microscopy (SEM) technique, which confirmed a homogeneous distribution of reinforcing agents and refined grain structure.

Accelerated semantic segmentation of additively manufactured metal matrix composites: Generating datasets, evaluating convolutional and transformer models, and developing the MicroSegQ+ Tool

Data-driven applications are penetrating every aspect of Additive Manufacturing (AM) to enable efficient resolution of key existing challenges. One such application is semantic segmentation which automatically quantifies post-process structure data from graphic or 3D computer representations. In industrial settings, these models can expedite the development of new materials or processes. However, Additively Manufactured (AMed) materials offer unique challenges, which require new models to be developed and trained. These challenges include out-of-balance classes (e.g., defects), massive labeling efforts, and significant data preparation costs. Recent applications of semantic segmentation in AM have shown the potential of ensemble-based approaches at the expense of increased parameters and computational burden while ignoring the minority classes. In this work, we propose a reproducible method and develop an associated tool to rapidly segment and subsequently quantify industrial AMed metallographic images. First, two new datasets representing AMed materials are generated from extensive experimentation. Subsequently, state-of-the-art models from convolutional and self-attention categories are evaluated in their ability to segment the datasets of interest. Finally, a modular software tool is developed for industrial applications. The developed Microstructure Segmentation, Quantification, and Fusion (+) tool or MicroSegQ+ enables a weighted pairing of predictions from different semantic segmentation models. The pairing strategy helps to exploit the complimentary performance of convolutional and transformer models on multi-class metallographic images from a Metal Matrix Composite (MMC) material system. In addition to developing models on this MMC dataset, the proposed strategy is evaluated on an open-source metal AM dataset. We also evaluate the generalizability of the best-performing model on a second MMC dataset from a different industrial setting that shows an overall accuracy of 93 % without fine-tuning. The proposed tool enables rapid quantification under 1 min, unlike the existing semi-automatic approach that takes 1–2 h of segmentation effort on single bead cross-sections. The tool is wrapped into a single executable file for industrial deployment. The work also contributes to two annotated datasets from a direct energy deposition (DED) AM process. The datasets can be used to develop and validate new semantic segmentation models of AMed microstructures, whereas the functionality of the tool can be expanded upstream to include data and modeling steps, enabling a no-code pipeline for the industry.

Microstructure and mechanical properties of friction stir welded AZ31 magnesium alloy reinforced with ZrB2

Abstract Metal matrix composites (MMC) have advantages over polymer matrix composites such as high stiffness and strength, high-temperature resistance, better abrasion resistance, creep resistance, resistance to degradation by fluids, dimensional stability, and non-flammability. Metal matrix composites are used for various applications in the automotive, aerospace and sporting goods industries. The primary objectives of the current research work encompass the fabrication of Metal Matrix Composites (MMCs) AZ31 with 0.5%, 1.0% and 1.5% zirconium boride (ZrB2) nano-powder by the stir casting process, followed by welding through Friction Stir Welding (FSW). The metallographic analysis was carried out on the weldments of all cases. The macroscopic and microscopic analysis confirmed the defect-free weld joint. Tensile and hardness tests were conducted to study the mechanical properties of the materials. The tensile strength and the percentage of elongation increased with the percentage of ZrB2. But, after 1.0% addition of nano particles the strength decreased. The same pattern had been observed in both base and welded samples. The defect-free welding joints were fabricated with an efficiency of 79.1%, 79.7% and 77.7% for the materials with 0.5%, 1.0% and 1.5% nano powder, respectively. EIS and PDP tests were conducted in 3.5% NaCl to study the corrosion behaviour of base and welded materials. The corrosion tests on the base MMC samples showed that the corrosion resistance increased after the addition of ZrB2 nanoparticles. In addition, the corrosion resistance of all the welded samples improved compared with their respective base materials.

Effect of Interface Wettability on Additively Manufactured Metal Matrix Composites: A Case Study of 316L-Y2O3 Oxide Dispersion-Strengthened Steel

Laser powder bed fusion (LPBF) is a fusion-based additive manufacturing process. It has the advantage of allowing the manufacturing of metal matrix composites. This advantage arises from its small melting zone and rapid cooling rate, which minimize the risk of reinforcement segregation. In this work, 0.3 wt% and 1.0 wt% Y2O3 nanoparticles were added to 316L to fabricate oxide dispersion-strengthened (ODS) steels using the LPBF process. Notably, Y2O3 agglomerates were identified in the LPBF-fabricated 316L ODS steels, without inducing grain refinement, while the impact on tensile strength of Y2O3 addition proved negligible. Tensile elongation was decreased due to the poor bonding of the Y2O3 agglomerations to the matrix. The crucial role of the wettability of the reinforcement and the matrix in facilitating grain refinement and strength enhancement is discussed. The poor wettability of the Y2O3 particles and 316L emerged as the primary cause for Y2O3 agglomeration. This finding highlights the importance of addressing wettability issues to optimize the manufacturing process and enhance the overall performance of LPBF-fabricated metal matrix composites.

In-situ synthesis of spatial heterostructure Ti composites by laser powder bed fusion to overcome the strength and plasticity trade-off

Recent research has focused on laser in-situ additive manufacturing of metal matrix composites with spatially controllable microstructures (phases). This study, inspired by the process of inserting mesh fibers into reinforced concrete, synthesizes TiN in situ using laser powder bed fusion and N2 gas. The laser-melted track, embedded with TiN particles, formed a spatially heterostructured Ti composite (SHTC) with a three-dimensional, artificially controlled architecture in a pure Ti matrix. The influences of process parameters on the mechanical properties of the spatially heterostructured Ti composite and the microstructural evolution of TiN/Ti were investigated emphatically. The results showed that the growth direction of the microstructure was changed by laser powder bed fusion additive manufacturing with alternating N2–Ar gas under suitable N2 concentration and melting track spacing. Among all spatially heterostructured Ti composites, the TiN–Ti heterolayer net-like structure achieved a high ultimate tensile strength of ∼1.0 GPa and elongation of 27 %, demonstrating a superior strength-ductility combination than intrinsic pure Ti and uniform TiN composites, as well as traditional layered structure Ti-based composites. During the tensile test, the deformation behavior was monitored in situ using digital image correlation, and the fracture mechanism was investigated. Hetero-deformation induced strengthening and toughening potentially explains the mechanism behind the strength enhancement of spatially heterostructured Ti composites. Furthermore, this work may stimulate research and development in additive manufacturing of spatial heterostructures with configurable structures, targeting synergistic regulation of strength and ductility in the integration of structure-material-function.

Synthesis of Ni, Cu plated nano-Al2O3 composite powders and autocatalytic mechanism

This research proposes a novel method that combines sodium hypophosphite reduction, Ni re-activation, and electroless copper plating to fabricate pure Cu-Ni/Nano-Al2O3 composite powder. The research investigated the effects of the re-activator on the characteristics of Cu-Ni/Nano-Al2O3 composite powders and the autocatalytic mechanism of electroless copper plating on the nano-alumina surface under two re-activation conditions. The results showed that the method successfully eliminates Cu2O and improves the efficiency of electroless copper plating. During electroless copper plating, when Ni2+ is used as the re-activator, sodium hypophosphate only releases one electron and one active hydrogen, thus it cannot completely reduce the Cu2+. However, when nickel is used as the re-activator, sodium hypophosphite can release active hydrogen in two steps and reduce the Cu2+ to Cu. The purification strategy proposed, and the relationship between the electroless plating process and the autocatalytic activity of metals are highly valuable for manufacturing metal matrix composites in special applications.

A reaction study for Al–Ni2O3 nano self-exothermic materials

Cast-infiltration has emerged as a prevalent technique for fabricating metal matrix composites. Studying Al–Ni2O3 nano self-exothermic materials proves valuable, given their potential to enhance metal matrix composites' casting defect resolution as nano self-exothermic materials. This study analyzes reaction characteristics, mechanisms, parameter-exothermic characteristic relationships, moderating methods, and their respective influences. Reaction products from Al–Ni2O3 nano self-exothermic materials include Al2O3, AlNix, and trace amounts of Al. The closer the powder's composition ratio aligns with equilibrium stoichiometry, the smaller the heat released during self-exothermic reactions; smaller powder particles result in larger self-exothermic reaction heat releases and lower reaction temperatures, with reactions ceasing when exceeding the critical size (l > 40 μm). Different reaction environments also impact reaction products, with comparatively lesser effects on reaction temperatures. By modulating powder parameters and reaction conditions, Al–Ni2O3 nano self-exothermic materials' reaction temperature can be adjusted between 609 °C and 900 °C. Correspondingly, the reaction exotherm ranges from 232 J/g to 1560 J/g, providing heat compensation for subsequent composite material casting.

New Approach for Manufacturing Ti–6Al–4V+40%TiC Metal-Matrix Composites by 3D Printing Using Conic Electron Beam and Cored Wire. Pt. 1: Main Features of the Process, Microstructure Formation and Basic Characteristics of 3D Printed Material

In this paper, a new approach for additive manufacturing metal-matrix composites based on Ti–6Al–4V titanium alloy reinforced with titanium carbide particles, as well as layered structures consisted of such composite and Ti–6Al–4V alloy layers is considered. The approach is based on 3D printing with a conical electron beam using a special cored wire, whose composition corresponds to metal-matrix composite. The issues of production such a wire, the features of the 3D printing process, when using it, as well as the features of formation of the microstructure and phase composition of the printed composite material are described. The issues of titanium-carbide particles’ wetting with Ti–6Al–4V melt during process of 3D printing, as well as possible thermogravitational effects (floating or drowning) for solid TiC particles within the melt are considered in detail with additional experiments. The influence of individual components of the wire composition on the formation of the microstructure and its uniformity over the cross section of the printed layer is shown. The possibility of controlling the formation of homogeneous structural state and obtaining sufficiently high values of the hardness (of above 600 HV) of the metal-matrix composite layer printed on the Ti–6Al–4V baseplate is shown.

Detonation Spraying of Ni-Based Composite Coatings Reinforced by High-Entropy Intermetallic Particles

Ni-based composite coatings reinforced by high-entropy intermetallic compounds (HEICs) were prepared by detonation spraying (DS) on low alloy steel substrates. To this end, first (Ti-Nb)(V-Cr-Ni-Fe) and Al3(TiZrNbCrHfTa) HEIC powders were fabricated by arc melting followed by ball milling. The as-milled HEIC powders were then employed as reinforcement particles to prepare Ni-7wt.% HEIC composite coatings. The average particle size of the (Ti-Nb)(V-Cr-Ni-Fe) and Al3(TiZrNbCrHfTa) HEIC powders were 18 and 35 µm, respectively, while the average particle size of the Ni powder was 56 µm. (Ti-Nb)(V-Cr-Ni-Fe) exhibited a single hexagonal C14 Laves phase in spite of Ti and Nb segregations. The XRD pattern of Al3(TiZrNbCrHfTa) indicated the presence of a tetragonal D022-type structure along with some minor CrTi and Cr5Al8 phases. The sprayed Ni-7wt.% FeNiCrV-TiNb and Ni-7wt.% Al3(TiZrNbCrHfTa) composite coatings retained crystal structures of the powder mixtures, suggesting proper thermal stability for both powders. The coatings exhibited a dense microstructure consisting of a lamellar microstructure with low porosity and sound bonding with the substrate. The microhardness of Ni-7wt.% FeNiCrV-TiNb (450 HV) was higher than that of Al3(TiZrNbCrHfTa) (338 HV), and it exhibited lower fluctuation than that of Ni-7wt.% Al3(TiZrNbCrHfTa). DS is an effective method to fabricate metal matrix composites reinforced by HEICs with a low level of porosity.

Freeform thermal-mechanical Bi-functional Cu-plated diamond/Cu metamaterials manufactured by selective laser melting

The leverage of selective laser melting (SLM) successfully fabricate metal matrix composites (MMCs) metamaterials with freeform intricate triply periodic minimal surface (TPMS) structures that are not possibly fabricated by conventional methods and exhibit exceptional mechanical properties. SLM fabricated high precision MMCs metamaterial TPMS structures are of great potential in energy conversion, heat management and lightweight applications. Due to the self-supporting geometric characteristics of TPMS, the metamaterial structures could effectively overcome the manufacturing constraints of SLM. Besides, their freeform capability offers great opportunities to be bi-functional or multi-functional through the selection of materials as well as the design optimization of structure. Diamond can offer unique advantages in the field of heat management due to its outstanding thermal and mechanical properties. The addition of micro-sized diamond particles into copper can tailor its coefficient of thermal expansion (CTE) while enhancing its thermal conductivity (TC). SLM fabricated diamond reinforced copper MMCs metamaterials with TPMS structure could bring outstanding thermal-mechanical bi-functional properties for prospective lightweight thermal management applications. In our previous work, the interfacial bonding issue between diamond particles and Cu matrix was resolved by a coating of copper on micro-sized diamond particle reinforcement. In this present work, 1 vol% Cu-plated diamond/Cu metamaterials with three various TPMS (Gyroid-G, Schwarz Primitive-P, Diamond-D) structures were successfully fabricated via SLM for the first time. Their bi-functional heat transfer and compression behaviors were evaluated by measurement and numerical simulation for three TPMS (G, P, D) structures and TPMS (D) structures with various lattice thicknesses. From the lightweight perspective of three TPMS structures with 0.2 mm wall thickness, the order of these structure is TPMS P structure, TPMS G structure, TPMS D structure (0.2 mm wall thickness, 0.2 P > 0.2 G > 0.2D). If heat transfer performance is an important consideration, The 0.2D structure can be selected from the three TPMS structures. This research also investigated the continuous design of TPMS D structure with various wall thickness and creatively proposed a flexible TPMS design paradigm toward advanced thermal-mechanical bi-functional Cu-plated Diamond/Cu metamaterials via SLM for prospective lightweight thermal management applications.

The Role of Friction Stir Processing Parameters and Hybrid ZrC/WC Reinforcement Particles in Improving the Surface Composite Dissimilar Matrix’s Dynamic Behavior and Microstructure Refinement

This study examined the impact of hybrid reinforcement particles, specifically zirconium carbide (ZrC) and tungsten carbide (WC), as well as the parameters of friction stir processing (FSP), on the microstructure, mechanical properties, and dynamic behavior of aluminum alloys. The hybrid particles were integrated into the aluminum alloy using friction stir processing (FSP). The fabricated metal matrix composites (MMCs) were characterized using optical microscopy, scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The results showed that the FSP parameters and reinforcement particles played an important role in improving the grain refinement of the MMCs. This study’s results suggest that the FSP samples’ UTS can be maximized using a tool rotation speed of 600 rpm and a traverse speed of 30 mm/min. The grain refinement in the composite surface was attributed to the dynamic recrystallization during the friction stir processing (FSP) process. The reinforcement particles also acted as grain growth restrictors, further refining the grain size. This resulted in a 34% increase in ultimate tensile strength compared to AA2024 alloys and a 12% increase compared to AA7075 alloys. The composite surface also exhibited enhanced dynamic properties, with an increase in impact energy of 26%. The free vibration test showed that the hybrid reinforcement particles significantly improved the strength and damping capacity of the aluminum alloys, resulting in a high resonant frequency. This is important for applications such as vibration damping and noise reduction.

Directed energy deposition of SS 316L/SiC composites using coincident and coaxial wire-powder feeding

The wire-powder fed directed energy deposition (WP-DED) process enables the fabrication of metal matrix composites (MMCs) with a high deposition efficiency. Lateral wire-powder feeding as well as lateral wire and coaxial powder feeding are two existing methods for WP-DED of MMCs. However, the lateral filler injection limits the fabrication of three-dimensional parts with complex geometry. In this study, we applied the coaxial wire-powder fed DED (CWP-DED) to fabricate the SS 316L/SiC parts with different SiC weight fractions. The effects of SiC content on defects and microstructure of as-built parts were investigated. Three types of interior defects including pores, inclusions, and cracks were observed in as-built samples fabricated with high SiC content. With an increase in SiC content, the grains were refined by dissolved nano-scale SiC particles and more γ-(FeCrNi) phases transformed into α-(FeCrNi) phases. Tensile properties and the underlying strengthening mechanisms of as-built SS 316/SiC specimens were elucidated. This paper will guide the process development for CWP-DED of high-performance MMCs.

Enhanced plasticity due to melt pool flow induced uniform dispersion of reinforcing particles in additively manufactured metallic composites

Additive manufacturing has gained increasing interest to fabricate metal matrix composites. Particle agglomeration remains a critical challenge and can severely compromise the mechanical properties, in particular tensile ductility. Here we investigated and utilized laser powder-bed-fusion (L-PBF) to uniformly disperse particles in metal matrices, taking advantages of particle flow dynamics during melting and remelting. We demonstrate our approach in a TiB2 reinforced aluminum system and produce a high dispersion of fine TiB2 particles (with sizes down to tens of nanometers) in a single print. Both micron- (1-5 μm) and nano-sized (40 nm) TiB2 particles are found to be uniformly dispersed in composites, with a volume fraction of up to 25%. High-fidelity computer modeling indicates that although particles flow with Marangoni vortexes, the melt pool overlapping and subsequent re-melting/re-solidification play an important role for the successful dispersion. The propelling effect of vapor depression and particle filling via the Marangoni vortex flow are the two main mechanisms that lead to the uniform dispersion. A geometric criterion for hatch spacing is derived and verified by experiments for the successful uniform dispersion of reinforcing particles. Compared to composites with nonuniform particle dispersion, L-PBF aluminum 2024 composites show ∼30% higher tensile strength and ∼16% higher Young's modulus, together with a marked improvement of tensile ductility (up to three times higher). The uniform dispersion of reinforcing particles is also achieved in copper materials and thus demonstrates the versatility of our approach to other metals and alloys.

Application of metal matrix composite fabricated by reinforcement materials – A review

Metal Matrix Composites (MMCs) are recently developed fabricated materials with characteristics like reduced thermal expansion coefficient, enhanced specific strength, improved wear resistance, and light in weight. They contain feature such as low density, good strength-to-weight ratio, lightweight, low cost, excellent quality, and high performance. Among others, Aluminium (Al) and Al alloy based MMCs are employed in a variety of industrial applications. The characteristics of the composite are greatly influenced by the Al-based MMC fabrication processes. The manufacturing processes for reinforced composites as well as contemporary fabrication techniques are reviewed in present article. The impact of various process factors on the characteristics of aluminium based MMC has also been discussed. Various techniques such as powder metallurgy, stir casting, hand lapping etc. are utilized for the fabrication of composites. The primary objective of the present work is to review different fabrication methods of Al MMCs along with their features. This article also deals with changes occur in mechanical and physical properties with fabrication methods. The effects of the addition of different reinforcement have also been discussed in the present work. Investigation of mechanical and microstructure properties have also done in this paper. The main purpose of this review is to find effect of fabrications process on different properties of fabricated material as well as finding of suitable method of fabrication.

Latest Developments to Manufacture Metal Matrix Composites and Functionally Graded Materials through AM: A State-of-the-Art Review.

Multi-material structure fabrication has the potential to address some critical challenges in today's industrial paradigm. While conventional manufacturing processes cannot deliver multi-material structures in a single operation, additive manufacturing (AM) has come up as an appealing alternative. In particular, laser-directed energy deposition (L-DED) is preferred for multi-material AM. The most relevant applications envisioned for multi-material L-DED are alloy design, metal matrix composites (MMC), and functionally graded materials (FGM). Nonetheless, there are still some issues that need to be faced before multi-material L-DED is ready for industrial use. Driven by this need, in this literature review, the suitability of L-DED for multi-material component fabrication is first demonstrated. Then, the main defects associated with multi-material L-DED and current opportunities and challenges in the field are reported. In view of the industrial relevance of high-performance coatings as tools to mitigate wear, emphasis is placed on the development of MMCs and FGMs. The identified challenges include-but are not limited to-tightly controlling the composition of the multi-material powder mixture injected into the melt pool; understanding the influence of the thermal history of the process on microstructural aspects, including the interactions between constituents; and studying the in-service behaviours of MMCs and FGMs with regard to their durability and failure modes.

Novel solid-state metal powder surface modification process for additive manufacturing of metal matrix composites and alloys

Although metal additive manufacturing has been widely studied owing to its flexible product shape design, the material selection window for metal additive manufacturing remains narrow owing to limited feedstocks. To address the challenges in additive manufacturing, an innovative metal powder fabrication process was developed in this study. This process is known as surface modification and reinforcement transplantation (SMART), and it efficiently produces surface-modified feedstock powders, such as spheroidized, surface-alloyed, surface-coated, or composite powders, which facilitate the exploration of new alloys and composites via additive manufacturing. In this study, the working principles of the SMART process were established, and some practical applications of the SMART process were considered by fabricating specialized metal additive manufacturing feedstocks such as carbon nanotube-coated, Mo alloyed, and TiC particle-reinforced Inconel 625 powders. Furthermore, Mo-alloyed and TiC particle-reinforced powders were utilized in the directed energy deposition process to validate the performance of the SMART powder by fabricating Mo-controlled alloy and TiC particle-reinforced composites. The SMART process was compared with the existing processes and proved to be advantageous. Therefore, this study provides a novel method for producing feedstock powders for additive manufacturing.

Applicability of Industrial Wastes in Metal Matrix Composites Production – A Review

The review study is to investigate the possibility of utilizing industrial waste materials as a strengthening component in the manufacturing of metal-matrix composites (MMCs) and assess the associated environmental benefits. The study focused on examining two distinct sets of waste materials: metal matrix composites that were reinforced with fly ash, and composites produced from different kinds of industrial waste materials. Technical and property-related data were reviewed to evaluate the potential of these waste materials in MMC production. The study results indicated that fly ash-reinforced metal-matrix composites exhibited exceptional physical and mechanical properties, which make them well-suited for various applications, particularly in the automotive sector. The research highlights the necessity for further studies to innovate advanced materials with improved properties while mitigating environmental pollution. Overall, the research demonstrates the potential of utilizing industrial waste materials as reinforcement in MMC production and underscores the importance of this approach for the future development of advanced materials.