Aluminium-copper (Al-Cu) metal matrix composites combine the best qualities of copper and aluminium, providing exceptional electrical and thermal conductivity, high strength and a lightweight design. These composites have attracted significant interest for use in advanced manufacturing, electronics, the automotive industry and the aerospace sector. In this work, powder metallurgy was used to fabricate and analyze Al-5Cu composites reinforced with aluminum oxide (Al2O3). High-purity Al and Cu powders were mixed with different ratios of Al2O3 (1%, 3%, and 5% by weight) to examine their effects on microstructure, microhardness, and density of Al-Cu composite. The T6 process, which includes solution treatment and artificial aging, was used to heat treat the powder blends following cold pressing. The results showed that density increased along with the Al2O3 content, reaching a peak of 3%. Vickers microhardness tests showed a significant improvement, with the 5% Al2O3 composite having the highest microhardness (64 HV0.1). Microstructural analysis confirmed a uniform distribution of Al2O3, even though etching made it difficult for optical microscopy to clearly show grain boundaries. The Al2O3 particles mechanistically increased microhardness by preventing dislocation movement and encouraging grain refinement, despite the difficulty of making accurate measurements of grain size. The composites displayed a consistent microstructure with no observable phase segregation, and the mechanical improvements were in line with predictions made by the rule of mixtures and particle reinforcement theories. It was concluded that Al2O3 addition successfully increases the microhardness and microstructural stability of Al-5Cu composites.

Additive Manufacturing (AM) has emerged as a transformative production route capable of fabricating complex, lightweight, and customized components through layer-wise material consolidation. When integrated with Powder Metallurgy (PM), AM offers expanded opportunities for manufacturing high-performance metal and ceramic parts with tailored microstructures and enhanced functional properties. This review systematically amines the principal powder-based AM technologies-including Powder Bed Fusion (PBF), Binder jetting (BJ), Directed Energy Deposition (DED), Material Jetting (MJ), and Cold Spray (CS)-by discussing their operating mechanisms, powder-process interactions, advantages, limitations, and industrial use cases. Particular attention is devoted to powder characteristics such as particle morphology, size distribution, chemistry, and flowability, which govern powder spreadability, densification behavior, melt pool stability, and final component quality. comprehensive overview of commonly employed powder systems is also presented, spanning ferrous steels, tanium alloys, nickel superalloys, aluminum alloys, cobalt-chromium alloys, copper alloys, high-entropy alloys, rare-earth-containing powders, ceramics, and metal-ceramic composites. Microstructure formation, defect mechanisms, and resultant mechanical performance are analyzed in the context of specific AM processes. Emerging developments-including multi-material deposition, hybrid additive-subtractive manufacturing, AI-driven process monitoring, and improved powder recycling-are highlighted for their potential to enhance sustainability, scalability, and application diversity. Overall, this review consolidates current knowledge on powder production, powder-process relationships, and material behavior in AM, providing a framework for understanding how PMcontinues to shape the evolution and industrial adoption of metal AM.

This study systematically investigates the effect of boron (B) addition on the microstructural evolution, mechanical properties, high-temperature wear behavior, and corrosion resistance of CoCrCuFeNiTiBx (x = 0-1) high-entropy alloys produced via mechanical alloying and powder metallurgy. Phase constitution and microstructural changes were analyzed using XRD and SEM, revealing progressive boride formation and microstructural refinement with increasing boron content. Mechanical characterization demonstrated a pronounced strengthening effect, with hardness increasing from approximately 500 HV in the boron-free alloy to a maximum of 670 HV and a nanohardness of 10.98 GPa for the CoCrCuFeNiTiB0.7 composition. Tribological tests conducted under room temperature and elevated temperature (650 degrees C) conditions showed that boron addition fundamentally alters the wear response of the alloys. While wear at room temperature was governed primarily by mechanical abrasion and adhesion, high-temperature sliding induced an oxidation-assisted wear mechanism. Notably, CoCrCuFeNiTiB0.7 exhibited the lowest wear rates under conditions, achieving 13.79 x 10-5 mm3/N.m at room temperature and retaining excellent wear resistance at 650 degrees C with a value of 15.61 x 10-5 mm3/N.m, indicating remarkable thermal stability. Electrochemical measurements further revealed that this alloy possessed the lowest corrosion current density (icorr = 3.17 x 10-3 A/cm2) and the minimum corrosion rate (0.315 mm/ y), corresponding to an approximately 7.5-fold improvement compared to the boron-free alloy. Post-wear and post-corrosion SEM-EDX analyses confirmed that the superior performance of the B0.7 alloy arises from the synergistic effect of boride strengthening and the formation of a dense, adherent oxide layer at elevated temperatures. Overall, the results identify an optimal boron content that enables CoCrCuFeNiTi-based high-entropy alloys to overcome the conventional trade-off between hardness, wear resistance, and corrosion performance, making them highly promising for demanding high-temperature tribological applications.

The automotive, aerospace, and defense industries require the development of advanced lightweight composites with exceptional mechanical and tribological properties. This work examines the effects of adding various ceramic particles to mechanically alloyed aluminum/alumina (Al/Al2O3). Reinforcement agents were selected due to their unique contributions to wear resistance, density, hardness, and microstructural refinement. These include silicon carbide (SiC), carbon nanotubes (CNT), nanosilica (NS), nanoclay (NC), and rare earth oxides (La2O3, Nd2O3, and Sm2O3). The comprehensive characterization methods used to evaluate the structural and functional performance of the composites included Vickers microhardness testing, FTIR spectroscopy, FESEM imaging, EDS mapping, density measurements, and tribological wear testing. FTIR analysis confirmed that the ceramic additives bonded solidly to the matrix. Furthermore, the friction resistance was found to be enhanced by NS and CNT. Although some adhesive wear was observed in CNT-reinforced samples, SEM images of the wear tracks showed that abrasive wear consistently remained the predominant mechanism across all composites. Overall, the findings demonstrate that, by carefully selecting and combining ceramic reinforcements, Al/Al2O3 can be effectively modified to increase hardness, density, and resistance to wear. Because of this, these materials are desirable choices for engineering applications requiring lightweight construction, high stress, and high wear.

The effects of Tungsten Cobalt (WCo) nanoparticle contribution on the shear and bending strengths are examined in adhesively bonded single-lap joints made with glass fiber-reinforced polymer (GFRP) substrates in this study. WCo particles were synthesized via mechanical alloying and added to epoxy adhesives at varying concentrations (1.0, 3.0, and 5.0 wt.%). The adhesive mixtures were used to bond GFRP plates in single-lap joints (SLJ), and their mechanical performance was evaluated under shear and bending loading conditions. The shear strength results indicate that the incorporation of 1.0 wt.% WCo increased shear strength by 68.5%, while 3.0 wt.% WCo yielded the highest improvement at 136%. However, the addition of 5.0% WCo led to a reduced enhancement (60%) due to nanoparticle agglomeration and local stress concentrations. Notably, the maximum bending stress was observed in the 3% WCo-containing specimens. Specifically, the bending load increased by 51.5%, from 61.96 MPa in the pure epoxy specimen to 93.85 MPa in the 3% WCo-reinforced specimen. Failure surface analysis revealed that WCo-reinforced samples exhibited light-fiber tear, thin-layer cohesive failures, and enhanced bonding properties due to increased viscosity and the filling of micro-voids. These findings suggest that WCo nanoparticles effectively improve the shear and bending performance of epoxy adhesives by enhancing interfacial bonding, ductility, and stress distribution mechanisms. The study provides insights into the potential of WCo-reinforced adhesives as a cost-effective and high-performance solution for engineering applications.

Seramik parçacıkları ile takviye edilmiş metal matriks kompozitleri (MMCs), takviye edilmemiş matrislere kıyasla artırılmış dayanım, aşınma direnci ve termal stabilite gibi üstün özellikler sunar. Bu çalışma, toz metalurjisi ile üretilen Al-Cu kompozitlerinin mikroyapısı, yoğunluğu ve sertliği üzerindeki değişen magnezyum oksit (MgO) içeriğinin etkilerini incelemektedir. MgO, %1, %3 ve %5 ağırlık oranlarında eklenmiş ve kompozitler, Vickers mikrosertlik testi, Arşimet Prensibi ile yoğunluk ölçümü ve mikroyapısal analizler gibi çeşitli yöntemlerle karakterize edilmiştir. Sonuçlar, MgO eklenmesinin kompozit yoğunluğunda hafif bir artışa yol açtığını, en yüksek sertlik değerlerinin ise %1 MgO içeren kompozitte gözlendiğini göstermektedir. MgO parçacıklarının varlığı, sert seramik parçacıkları ve intermetalik fazların oluşumu yoluyla plastik deformasyonu sınırlayarak sertliği artırmaktadır. Ayrıca, MgO’nun eklenmesi, muhtemelen çekirdeklenme ajanı olarak rol oynayarak tane yapısını iyileştirmiş ve bu da mekanik özelliklerin daha da gelişmesine katkı sağlamıştır. Bu çalışma, MgO’nun Al-Cu kompozitlerinin özelliklerini iyileştirmedeki rolüne dair değerli bilgiler sunmakta ve yüksek dayanıklı, hafif malzemelere ihtiyaç duyan sanayilerdeki potansiyel uygulamaları vurgulamaktadır.

Magnezyum ve alaşımları, olağanüstü mukavemet-ağırlık oranı, düşük yoğunluk, mükemmel dökülebilirlik, işlenebilirlik ve bulunabilirlik özellikleri nedeniyle havacılık ve otomotiv endüstrilerinde hafif yapısal uygulamalar için çok değerlidir. Ancak, düşük mukavemet, zayıf süneklik ve sınırlı soğuk işlenebilirlik özellikleri nedeniyle kullanım alanları sınırlıdır. Geleneksel alaşımlama yöntemleri mekanik özellikleri iyileştirir, ancak yine de alüminyum alaşımları ve çeliğe kıyasla yetersiz kalır. Bu durum, mekanik özellikleri iyileştirmek için mikron ve nano boyutlu takviyelere odaklanan magnezyum bazlı metal matris kompozitler (MMC'ler) konusunda önemli araştırmalara yol açmıştır. Bu çalışma, mekanik alaşımlama yaklaşımı kullanılarak nanosilikayla takviye edilmiş AZ91 alaşımının üretimini araştırmakta ve farklı nanosilikal oranlarının (1%, 3% ve 5%) malzeme özellikleri üzerindeki etkilerini incelemektedir. Mekanik alaşımlama işlemi, planet yüksek enerjili bilyalı değirmen kullanılarak gerçekleştirilmiş ve elde edilen tozlar soğuk preslenerek yığın alaşımlara dönüştürülmüştür. Kompozitlerin yoğunlukları Arşimet prensibi kullanılarak ölçülmüş ve nanosilikanın numunelerdeki gözenekliliği doldurma kabiliyeti nedeniyle genel yoğunluğu artırdığı ortaya çıkmıştır. Sertlik ölçümleri, nanosilikanın sertlik değerlerini artırdığını göstermiştir. En yüksek sertlik, %5 nanosilikalı numunede gözlemlenmiştir. Genel olarak, nanosilikalı takviye, AZ91 alaşımlarında hem yoğunluğu hem de sertliği artırmıştır. Bu sonuçlar, yüksek performanslı uygulamalar için gelişmiş magnezyum bazlı MMC'lerin geliştirilmesine yardımcı olmaktadır.

Magnesium (Mg) stands out as a prevalent material in engineering, finding essential utility as a biomaterial due to its unique combination of low density, stiffness, high damping capacity, superior bending resistance, and impressive specific strength. Despite its high reactivity and somewhat inadequate mechanical properties for rigorous engineering applications, the incorporation of reinforcing nanoparticles has shown significant potential in enhancing the performance of magnesium-based composites. This study investigates the microstructure evaluation, hardness, and density of magnesium composites reinforced with nanoclay using a powder metallurgy approach. Nanoclay was preferred as a reinforcement element at weight percentages of 1%, 3%, 5%, and 7%. The densities of the composites were measured using the Archimedean principle, revealing that the addition of nanoclay generally increases the density of the composites due to the higher density of nanoclay compared to pure magnesium. However, the composite with 5% nanoclay exhibited a lower density than the one with 3% nanoclay, likely due to agglomerations leading to increased internal voids. Surface preparation for Vickers hardness testing involved sanding with 600, 1000, and 2000 mesh sanders, followed by polishing with 6μ and 3μ diamond suspensions. Hardness measurements, conducted using an AOB Vickers microhardness tester, indicated that the highest hardness value was observed in the composite with a 7% weight percentage of nanoclay, demonstrating that nanoclay addition enhances hardness. However, the composite with 3% nanoclay showed lower hardness compared to other reinforced composites. Optical images of the structures revealed metallographic spots indicative of contamination. These findings contribute to the understanding of the structural and mechanical behavior of nanoclay-reinforced magnesium composites, highlighting the potential for optimizing such materials for various applications in automotive, aerospace, and medical fields.

Azo dyes are known to cause environmental pollution and freshwater contamination, posing carcinogenic risks to human health. Consequently, researchers have directed their attention towards studying effective methods for removing these dyes from textile effluent. Amorphous alloys have emerged as a promising candidate for enhancing degradation efficiency on azo dyes, with various metallic alloys undergoing extensive investigation. Notably, the novel catalytic metallic materials exhibit significantly higher degradation performance compared to traditional options. Among the promising candidates are nanometallic alloys based on Fe, Mg, Co, Al, and Mn, which offer improved potential for cleaning diverse types of azo dyes from wastewater. The purpose of this review is to provide an update of the research regarding the use of amorphous alloys in azo dye degradation. The different production methods of amorphous alloys were discussed. The amorphous alloys used in dye degradation studies were subcategorized into three main types: Fe-based, Mg-based and some miscellaneous-based amorphous alloys. Additionally, the study delves into the impact of crucial parameters, such as solution pH and initial dye concentration, providing valuable insights for the efficient treatment of wastewater. Amorphous alloys with different structures and constituent elements have been synthesized and utilized in various applications. This paper reviews the studies related to the use of amorphous alloys in the removal of azo dyes from aqueous solutions. image

The demand for lightweight, high-performance aerospace and automotive components is growing, prompting interest in utilizing abundant materials like magnesium and its alloys and composites. However, pure magnesium's reactivity and mechanical weaknesses hinder its use in demanding engineering applications. To address this, magnesium is often reinforced with nanoparticles, leading to the development of magnesium matrix composites with improved mechanical properties. This paper systematically investigates the effects of kaolin on microstructure, hardness, and density for magnesium composites through the use of powder metallurgy. Results indicate that increasing kaolin content generally enhances density and hardness. These findings contribute to the understanding of kaolin-reinforced magnesium composites and their potential for improved mechanical properties in various applications.

Rare-earth hexaborides are a group of materials composed of octahedral boron units. They are useful for making advanced ceramics that have a wide range of industrial applications due to their low electronic work functions, hardness, refractory properties, low electrical resistances and specific thermal expansion coefficients. Rare-Earth Metal Hexaborides: Synthesis, Properties, and Applications provides a quick reference on rare-earth metal hexaborides and their engineering applications. It provides a primer on rare earth elements followed by details of rare-earth hexaboride structures, synthetic methods, and information about their alloys and ceramic composites. References to scholarly research are also provided for assisting advanced readers. This reference is a handy source of information for chemical engineering and materials science scholars, and anyone interested in the applied chemistry of rare-earth metals and borides.

In this section, the elemental forms of rare-earth elements are iron gray to silvery lustrous metals that are typically soft, malleable, ductile, and usually reactive, especially at elevated temperatures or when finely divided. rare-earth elements are examined in terms of physical and chemical properties. This makes them essential components of diverse defense, energy, industrial, military technology, and low-carbon technologies. Furthermore, REEs are rapidly being used in magnet applications. For example, magnets produced by Neodymium-iron, the strongest known type of magnet, are used widely. Thus, their application areas vary from the electronic to glass industry. Also, information about the sources of rare-earth elements is given in this part.

Rare-earth hexaborides (REB6 ) are composed of rare-earth elements and octahedral 3D boron units. In Chapter 1, rare-earth elements were examined in detail; in this part, the REB6 will be explained. Hence, rare-earth hexaborides (REB6 ) consisting of rare-earth elements and octahedral bor units are a group of ceramic materials that have a simple cubic structure with Pm3m symmetry. Their low electronic work function, low electrical resistance, and thermal expansion coefficient (in some temperature ranges), as well as high hardness and stiffness, high chemical and thermal stability, and melting points, provide a wide range of industrial uses from metallurgy to electronics.

Rare-Earth metal hexaborides (REB6 ) can be composited with some kind of ceramics, such as SiC, MgO, Carbon Nanotube, and Alumina. These types of composites can show excellent mechanical, optical, and thermionic properties. For example, SiC ceramics have high condensation behavior, high corrosion resistance, high thermal shock resistance, and high hardness properties; MgO ceramics have high fire resistance, high thermal conductivity, and low electrical conductivity properties; Carbon nanotubes have high optical and mechanical properties and Al2O3 ceramics have high abrasion and corrosion resistance and low density. The sizes of these materials are also significant as nano, and micro-sized ceramic materials have different properties when forming a composite with REB6 or any materials.

Water-soluble carbon quantum dot (CQD) nanoparticles were synthesized using a one-step hydrothermal method, with sucrose and urea selected as carbon precursors. The synthesized CQDs were characterized through SEM, TEM, X-ray diffraction, UV-Vis spectrum, FTIR, and fluorescence spectra analyses. HR-TEM results revealed the microstructure of CQDs as spherical-shaped particles, while XRD plots indicated their amorphous nature. XPS analysis confirmed the successful synthesis of N-doped CQDs. Moreover, this study introduced the reinforcing effect of CQD nanoparticles for the Al composites. The incorporation of CQD particles led to improved hardness properties of the Al–Zn–Mg–Cu composites by using Vickers tester. Additionally, SEM results suggested that CQD particles contributed to a grain fining effect, thereby reducing grain boundary separation.

To produce rare-earth hexaborides, some methods exist: direct solid phase, carbothermal reduction, borothermal reduction, self-propagating synthesis, aluminum flux method, spark plasma sintering, and mechanochemical synthesis, floating zone method, and chemical vapor deposition. In this section, the drawbacks and advantages of these production methods will be discussed.

This research investigates the production of epoxy resin composites reinforced by the synthesized heavy tungsten alloys (W-7Zn-3Co-Y2O3). Y2O3 is used for dispersion of the compound during the ball milling process. Laminating resin component A and hardened component B were used to produce polymer epoxy matrix. The tungsten heavy alloys reinforced epoxy composites were examined in terms of Vickers hardness, density measurement and microstructural characterization . The results indicate that the 16 hour-milled reinforced epoxy composites have the highest hardness value.

The structures of rare-earth hexaborides can be nanoparticles, nanowires, nanotubes, nanorods, nano-obelisks, nanocubes, nanocrystals and nanocons. These types of structures indicate superior properties, such as excellent mechanical, electronic, and optical properties. For these reasons, they are used in thermionic materials, electrical coating for resistors, sensors, and high-energy optical systems. Furthermore, their low work functions make them special for the design of optical devices, such as a cathode substance for cold (field) emission.

W-Zn-Co-Y2O3 tungsten heavy alloys were produced using a two-step mechanical milling method. In the first step, Zn-Co raw materials were milled for 24 h. Then, in the second stage, the Zn-Co compounds obtained were mechanically milled with tungsten (W) and yttrium(III) oxide (Y2O3). This study compared the new W-Zn-CoY2O3 alloy, obtained through two-stage mechanical alloying, with the same alloy produced using classical mechanical milling. The aim was to investigate and compare their structural, morphological, and mechanical properties. Yttrium oxide was used to promote the formation of in-situ oxide dispersoids during mechanical alloying. Oxide dispersion-strengthened tungsten heavy alloys are known for their exceptional mechanical properties, making them suitable for various high-temperature applications. The structures were analyzed using XRD, crystallite size, TEM, SEM, and EDX techniques. The microstrain of the final alloys was calculated as 15.79 x 10-3 and 13.12 x 10-3 for the classically obtained alloy and secondary milled alloys after 24 h of milling, respectively. Additionally, the reinforcing effects of the produced alloy on single-lap joints of aluminum composites were investigated. The results demonstrated that the tungsten alloy produced using the secondary ball method exhibited better mechanical performance.