Behavior Of Aluminum Matrix Composites Research Articles

Fatigue crack growth rate behaviour of aluminium matrix composites reinforced with hollow glass microsphere

This study investigates nanoindentation and fatigue crack growth rates of pure aluminium and aluminium hollow glass microsphere metal matrix composite (Al + HGM MMCs) cast plates. Using the stir casting method, pure aluminium, and Al + HGM MMCs were fabricated with hollow glass microsphere (HGM) additions ranging from 5 % to 30 % by weight. Nanoindentation techniques were utilized to assess fundamental mechanical properties such as hardness and elastic modulus. This study primarily focuses on analyzing fatigue crack growth behaviour within the linear region of da/dN vs. ΔK graphs for these stir-cast plates. Chevron-notch CT specimens were prepared following ASTM E-647 standards, and the constant amplitude increasing ΔK method was employed to generate Paris curves. Furthermore, the research investigated the influence of stress ratios (R=0.1, 0.2, and 0.3) on the fatigue crack growth rate in both Pure Al and Al + HGM MMCs. The study also determined the threshold and critical stress intensity factor ranges (ΔKth and ΔKc) for these plates. Additionally, Paris constants (C, m) were calculated to characterize the fatigue behaviour of the cast plates. X-ray diffraction analysis was conducted to reveal dislocation densities, crystalline sizes, and micro-strain responses of the fatigue-fractured specimens. Moreover, SEM fractography analysis provided insights into the fracture behaviour and crack branching observed in both pure aluminium and Al + HGM MMCs plates.

A Review of Dynamic Mechanical Behavior and the Constitutive Models of Aluminum Matrix Composites.

Aluminum matrix composites (AMMCs) have demonstrated substantial potential in the realm of armor protection due to their favorable properties, including low density, high specific stiffness, and high specific strength. These composites are widely employed as structural components and frequently encounter high strain rate loading conditions, including explosions and penetrations during service. And it is crucial to note that under dynamic conditions, these composites exhibit distinct mechanical properties and failure mechanisms compared to static conditions. Therefore, a thorough investigation into the dynamic mechanical behavior of aluminum matrix composites and precise constitutive equations are imperative to advance their application in armor protection. This review aims to explore the mechanical properties, strengthening the mechanism and deformation damage mechanism of AMMCs under high strain rate. To facilitate a comprehensive understanding, various constitutive equations are explored, including phenomenological constitutive equations, those with physical significance, and those based on artificial neural networks. This article provides a critical review of the reported work in this field, aiming to analyze the main challenges and future development directions of aluminum matrix composites in the field of protection.

A Review on Abrasive Wear of Aluminum Composites: Mechanisms and Influencing Factors

Aluminum matrix composites (AMCs) find extensive use across diverse industries such as automotive, aerospace, marine, and electronics, owing to their remarkable strength-to-weight ratio, corrosion resistance, and mechanical properties. However, their limited wear resistance poses a challenge for applications requiring high tribological performance. Abrasive wear emerges as the predominant form of wear encountered by AMCs in various industrial settings, prompting significant research efforts aimed at enhancing their wear resistance. Over the past decades, extensive research has investigated the influence of various reinforcements on the abrasive wear behavior of AMCs. This paper presents a comprehensive review of the impact of different variables on the wear and tribological response of aluminum composites. This review explores possible wear mechanisms across various tribosystems, providing examples drawn from the analysis of existing literature. Through detailed discussions on the effects of each variable, conclusions are drawn to offer insights into optimizing the wear performance of AMCs.

Design and fabrication of a super strong aluminum matrix composite with continuous titanium-based reinforcements

Super strong lightweight aluminum matrix composites (AMCs) were fabricated using selected laser melting (SLM) and micro-casting technology. The present AMCs show very high strength while maintaining a low density (e.g. σy = 1147 MPa, ρ = 3.7 g/cm3). This break the trade-off dilemma of strength and density in traditional AMCs. The nano/micro/macro-scale hybrid reinforcement involved in the present AMCs is proved an effective strategy for enhancing strength of AMCs. An FEM model was built to analyze the mechanical behavior of AMCs during compression. The simulation results are essentially consistent with the experimental results. Computation-aided design shows promise in reducing the cost and duration of continuous aluminum matrix composites development.

Effect of blending duration on physical, mechanical and tribological behavior of aluminum matrix composites: An experimental analysis

Aluminum matrix composites exhibit a vibrant role in the present research and scientific world due to their astonishing features compared to other conventional materials. Among the various techniques available for processing these composites, powder metallurgy (P/M) is considered one of the prominent techniques. This is because of its identical dispersal of the fillers, near net shape samples, etc. wherein blending is the most imperative step of the process. To accomplish efficient blending of the phases for composite preparation, ball milling is found to be suitable. In this paper, aluminum matrix composites filled with 20 wt% novel reinforcement (extracted from Aegle marmelos) is synthesized via the P/M technique by varying the blending duration from 60 to 240 min to study its effect on the behavior of composites. The mixing of the constituents is carried out at 300 rpm with a ball-to-powder ratio of 10:1 in ball milling. The blended powders were then compacted and sintered in an inert gas atmosphere for consolidation. The hardness, density, and wear tests were conducted to characterize the developed composite specimens. The microstructural characterization was carried out using an optical microscope and SEM, and the elemental composition of the synthesized composite was studied using EDS techniques. The hardness and density were found to have a growing influence up to a ball milling duration of 180 min and beyond this time there is found to be a decrement in the characteristics of the composites. This is due to the damage of the reinforcements observed during lengthier ball milling duration. The wear behavior of the fabricated specimens followed the same trend. Further, grey relational analysis was adopted in this study to determine the degree of relationship between the blending duration and the composites’ behavioral performance.

Role of B4C in the directed energy deposition of aluminum alloy 6061/B4C composite using core-shell powder for crack annihilation, pore mitigation, and grain refinement

Despite the high demand for additive manufacturing of high-strength aluminum alloys (60XX and 70XX), high-strength aluminum alloys are one of the most difficult materials to manufacture through metal additive manufacturing (MAM) because of their high laser reflectivity, thermal conductivity, low viscosity, and large solidification range. Thus, MAM products of high-strength aluminum alloys are characterized by pores, cracks, and irregular surface morphology. In the present study, the stable MAM behavior of aluminum matrix composites was achieved by adding B4C reinforcement to the feedstock powder in the form of a novel core-shell powder. The aluminum alloy 6061, which is notorious for its difficulty in MAM, was selected as the matrix. The core-shell B4Cp/6061 MMC powder was prepared for MAM via directed energy deposition (DED). The B4C addition effectively mitigated the formation of cracks, pores, and balling during DED. In addition, the grains were refined, thus preventing anisotropy and improving the mechanical properties. Furthermore, the favorable effect of B4C addition during DED was found to be caused by the formation of AlB2 during solidification. These findings provide a basic understanding of the promising potential of MMCs fabricated by MAM.

An overview of mechanical and corrosion properties of aluminium matrix composites reinforced with plant based natural fibres

Abstract Many researchers have become more interested in utilizing plant based natural fibre as reinforcement for the fabrication of aluminium matrix composites (AMCs) in recent time. The utilization of these environmentally friendly and cost effective plant based natural fibre is necessitated to avoid environmental pollution. The desire for cost-effective and low-cost energy materials in automotive, biomedical, aerospace, marine, and other applications, however, is redefining the research environment in plant based natural fibre metal matrix composite materials. As a result, the goal of this review study is to investigate the impact of agricultural waste-based reinforcements on the mechanical properties and corrosion behaviour of AMCs made using various fabrication routes. Processing settings can be modified to produce homogenous structures with superior AMC characteristics, according to the findings. Plant based natural fibre ash reinforcing materials such as palm kernel shell ash, rice husk ash, sugarcane bagasse, bamboo stem ash, and corn cob ash can reduce AMCs density without sacrificing mechanical qualities. Furthermore, efficient utilization of plant based natural fibre reduces manufacturing costs and prevents environmental pollution, making it a sustainable material. Brittle composites , unlike ceramic and synthetic reinforced composites, are not formed by plant based natural fibre reinforcements. As a result of our findings, plant based natural fibre AMCs have a high potential to replace expensive and hazardous ceramic and synthetic reinforced-AMCs, which can be used in a variety of automotive applications requiring lower cost, higher strength-to-weight ratio, and corrosion resistance.

Influence of nano titanium oxide reinforced Al-7075 matrix composites in stir casting method

Aluminium-based alloys have garnered a lot of attention as lightweight materials due to their outstanding mechanical qualities, good castability, and dimensional stability; they withstand damping capacity and abundance as a natural based mineral. The microstructural and interfacial properties of nano TiO2 can significantly impact the mechanical behaviour of Aluminium Matrix Composites (AMCs). The primary goal of this investigation is to extend novel creation of nanocomposite materials with an advantageous arrangement of thermal analysis, mechanical performances, oxidation process, and other mechanical characteristics. The samples were created using the conventional stir casting with aluminum-nano TiO2 composites. The interfaces were investigated using tensile, elongation, Vicker's hardness and scanning electron microscopy to understand the microstructural and interfacial evolution between Al 7075/nanoTiO2 matrix. The microstructural characterization of the nano based TiO2 reinforcing phases in the Aluminium matrix reveals a rather unvarying dispersion of the reinforcing phases. Compared to the parent material, the prepared composite exhibited a notable enhancement in hardness strength, elongation, and ultimate tensile strength.

Corrosion behavior of particle reinforced aluminum composites

Abstract In the study, the corrosion behavior of aluminum matrix composites reinforced with boron carbide (B4C), silicon carbide (SiC) and alumina (Al2O3) were investigated in saltwater (3.5 % NaCl). Composite materials were produced by powder metallurgy. For composite materials production, various reinforcement and aluminum powders were mixed by mechanical alloying for 4 and 10 hours. After mechanical alloying, mixed powders were compacted under 700 MPa pressure and sintered at 600 °C. Electrochemical corrosion tests were applied on specimens in the saltwater solution using potentiodynamic methods. According to the results of the investigation, the best corrosion resistance was obtained by aluminum/B4C and the lowest by aluminum/Al2O3 composites.

Preparation and characterization of nanodiamond reinforced aluminum matrix composites by hot-press sintering

In the present paper, aluminum matrix composites (AMCs) reinforced by nanodiamond (ND) were fabricated by hot-press sintering. The morphology and microstructure of ND/Al composite powders for different milling hours were observed. The effect of ND content on microstructure, mechanical properties and tribological behavior of AMCs was investigated. The relative density, hardness, compressive strength and wear resistance of AMCs with different ND contents were compared. The flake-shape aluminum particles with uniformly distributed ND particles were formed by ball milling for 15 h. A laminated structure of AMCs was formed by hot-press sintering at 550 °C for 5 min. ND was distributed at the grain boundary of Al matrix. At the interface between Al and ND, a layer of Al with high dislocation density was formed, which was closely connected with a layer of amorphous carbon. With increasing of ND content, more and larger pores were presented in AMCs, which caused a decrease in relative density. The hardness, compressive strength and wear resistance of AMCs were significantly improved in comparison with sintered aluminum. The AMC with 2.5% ND obtained the highest hardness and compressive strength and the lowest coefficient of friction and wear rate.

Influence of TiB2 addition on friction and wear behaviour of Al2024-TiB2 ex-situ composites

Present work encapsulated the friction and wear behaviour of aluminium matrix composites reinforced with different mass fractions of titanium diboride (TiB2) particles, synthesized by stir casting. A pin on disc tribotester was employed for conducting the dry sliding wear tests of Al2024-TiB2 composites. The tests were performed adopting various parameters like load, sliding distance and sliding velocity for investigating the effect of tribological parameters on the prepared composites. Microstructural characterization confirmed uniform dispersion of TiB2 particles and good matrix-reinforcement bonding. Results of the experiments revealed that, low friction and wear rates were observed in the developed composites compared to Al2024 alloy, whereas wear rates of both Al2024 alloy and fabricated composites increased with the increase in load, sliding velocity and sliding distance. However, friction coefficient of both Al2024 alloy and fabricated composites reduced with the increase in applied load but rose with the increase in sliding velocity and sliding distance. SEM studies of the worn surfaces and debris depicted that enhancement in wear resistance can be ascribed to finer debris formation.

Microstructural characteristics and mechanical behaviour of aluminium matrix composites reinforced with Si-based refractory compounds derived from rice husk

The microstructural characteristics and mechanical behaviour of aluminium matrix composites reinforced with Si-based refractory compounds (SRC) derived from rice husk were investigated. The reinforcement materials (SRC) were synthesized using a carbothermal processing technique. The reinforcement was used to prepare a 10 wt.% Al-Mg-Si alloy-based composite using a double stir casting process. The composites produced were characterized using microhardness, tensile properties, scanning electron microscopy (SEM), and X-ray diffractometer (XRD). From the results, A1650, C1650, and A1600 grades of the samples show more resistance to indentation due to the high proportion of hard SRC in the reinforced materials. Superior elongation values were observed for these composites A1650, C1650 and A1600 grades, respectively. The grades A1250, B1250, and C1250 series had the least toughness values within the range of 20–37% as compared to the control sample. For all composites under examination, the percent porosity was noted to be less than 4% and the strain to fracture was within 24–38%. Higher intensity of SiC was observed from the XRD spectrum and the formation of intermetallic materials. The tensile fracture surface morphologies of the composites produced were similar, showing a ductile dimple-like structure. The formation of a micro-crack and micro-void was also observed along the interphase.

Characterization, Prediction, and Optimization of Dry Sliding Wear Behaviour of Al6061/WC Composites

This investigation deals with an experimental analysis done on dry sliding wear behaviour of aluminium matrix composites reinforced with WC (tungsten carbide) particles. The composites were processed through powder metallurgy (P/M) technique with the addition of various fractions of WC particles. Results of scanning electron microscope (SEM) examinations and XRD analysis showed better dispersion of the reinforced particles and good matrix–reinforcement interface integrity. The results of dry sliding wear tests conducted on composite samples were analysed for varied conditions of WC volume fraction and sliding distance. The wear properties of composites were significantly affected by the variation of the WC volume percentage (5–25%). Smother wear tracks and closely spaced grooves on the composite pin worn surfaces were found for higher volume fraction WC particles. The postulated regression models for prediction of wear behaviour approximate their experimental values with an estimated error from 1.97 to 6.56%. The derived optimal wear properties to improve the sliding wear performance of the composites through a novel hybrid (GRA integrated TLBO) multi-response optimization approach are in a closer correlation with the experimentally measured values. Also, wear performance predicted values through hybrid multi-response optimization are closer to their validation experimental results compared with the predicted values through TLBO and GRA approaches. The derived optimal set of wear properties are 1.921 mm3/m wear rate and 0.292 coefficient of friction at 15 vol% of WC, 10 N applied load, 775 m sliding distance, and 1 m/s sliding velocity. The surfaces of the composite samples tested at the derived set of optimal wear behavioural parameters were also examined through SEM and analysed.

Macro-Micro Relationship of Dimensional Changing Behavior of Aluminum Matrix Composite

Accuracy and stability have always been the eternal pursuit of inertial navigation. Among them, the dimensional stability of inertial instrument materials is a key factor in determining the accuracy level of equipment. The dimensional changing(DC) behavior is a material problem extracted from the common accuracy drift problem in engineering technology. The DC behavior of 45vol% SiC P /2024Al composite under no load at constant temperature was systematically studied in-depth using in-situ heating XRD and double Cs-corrected transmission electron microscopy. The trend and magnitude of lattice constant and strain mapping of matrix near SiC/Al interface were both tracked and examined. A high-resolution thermal dilatometer was used to measure the macroscopic DC. Thermal mismatch residual stress has a decisive effect on the DC of SiC P /2024Al composite. The effect of exsolution on the DC of SiC P /2024Al composite was also discussed. Different dominant mechanism of DC between aluminum alloy and composites leads to the difference in the magnitude, rate, and stabilization of the dimensional change. In order to verify the validity of the mechanism, the DC results of different matrix and different heat treatment states were compared and explained. The estimation method of DC based on the volume change of unit cell could accurately predict the trend of DC and the magnitude of SiC P /2024Al composite. This provides instructive guidance for deeply understanding the DC behavior of aluminum matrix composites, and enriches the research work of micro-plastic deformation.

Optimization of wear parameters of aluminium matrix composites (LM6/Fly Ash) using Taguchi technique

Wear behavior of aluminum matrix composites (AMCs) has been studied. AMCs consist of LM6 aluminum alloy as the matrix material and 3%, 6% and 9% of particulate fly ash by weight as the reinforcement material. Stir casting process was used to produce the AMCs. Wear tests were performed on a pin on a disc machine according to ASTM G99 – 05 specifications. Taguchi's methodology was implemented and L27 orthogonal array was selected for conducting the wear tests. The main objective is to use S / N ratio and analysis of variance to investigate the effect of load, sliding distance, sliding speed and weight percentage of reinforcement on specific wear rate (SWR). Load has the largest statistical impact on SWR (24.31%) followed by sliding distance (16.43%). To validate the results of the experiments, confirmation tests were performed.

Drsna obraba kompozitov na osnovi aluminija, ojačanih z nanodelci grafena in SiC

Drsna obraba kompozitov na osnovi aluminija, ojačanih z nanodelci grafena in SiC

Mechanical properties and strain hardening behavior of aluminum matrix composites reinforced with few-walled carbon nanotubes

In this study, for the first time few-walled carbon nanotubes (FWCNTs) with ∼3 walls were used as reinforcements in fabricating high performance aluminum matrix composites (AMCs). FWCNTs/Al composites and referential Al materials were prepared by a powder metallurgy route consisting of high energy ball milling, spark plasma sintering (SPS) and subsequent hot extrusion. It is found that, by decreasing SPS temperature and time, FWCNTs/Al composites showed reduced grains with an increased dislocation density and improved structural integrity of FWCNTs, leading to an increased tensile strength. Meanwhile, comparatively high strain hardening rates and long strain softening behavior were observed after necking in the sample sintered at 500 °C, which resulted in a tensile elongation of 11.7% with a high yield strength of 382 MPa. The experimental results suggested that, compared with traditional multi-walled carbon nano-tubes (MWCNTs), FWCNTs showed a noticeably enhanced strengthening effect and provided a good balance of strength and ductility in Al composites. It may make FWCNTs a good reinforcement candidate for metal matrix composites to achieve improved mechanical properties.

Optimization of wear parameters for aluminium 4% fly-ash composites

Dry sliding wear behaviour of aluminium matrix composites (AMCs) prepared by stir casting with 4% as fly ash reinforcement has been studied in the work. Dry sliding wear tests have been conducted using a pin-on-disc wear-testing machine to study the effect of changeable process parameters such as load, time, and sliding velocity, which have been used as design variables on the output parameters wear rate (WR) and coefficient of friction (COF). Sensitivity analysis has been carried out to find out the most significant parameter that can be controlled to minimize the WR. Further, the wear parameters have been optimized using the technique for order of preference by similarity to ideal solution (TOPSIS) approach to reduce the WR. Therefore, this study offers useful insights to composite manufacturers, especially for automotive industries.

Wear behaviour of aluminium matrix composites (LM25/Fly Ash) – A Taguchi approach

Composite materials are mixtures of two or more materials with different chemical and physical properties. Various techniques are followed in the fabrication of composites materials; the most simple and less cost technique is Stir casting technique. Here the samples were prepared by stir casting technique with Aluminium cast alloy (LM25) as the matrix material and fly ash of (3, 6, 9% by wt) as the reinforcement material. In this paper Taguchi technique is opted for optimizing the wear characteristic-Specific Wear Rate (SWR). Experiments were carried out by using L27 Orthogonal array and the experimental factors are Load (L), Sliding Speed (S), Sliding Distance (D) and Reinforcement (R). ANOVA was carried out to find the most significant factor and percentage of contribution of each process parameters. To test the tribological properties of composites, pin on disk wear test under dry sliding conditions were carried out for the samples. Load has the largest statistical impact on SWR (38.5%) followed by sliding speed (18.72%). Confirmation tests were performed, to validate the optimization technique.

Mechanical properties and tribological behavior of aluminum matrix composites reinforced with Fe-based metallic glass particles: Influence of particle size

Aluminum matrix composites consisting of Al2024 and Fe-based metallic glass powders were prepared via powder metallurgy by using an optimized matrix to reinforcement particle size ratio, the influence of glassy particle size on mechanical properties and dry sliding wear behavior of the composites were investigated. The composites showed dense structure and homogenous three-dimensional distribution of the reinforcements independent of particle size. The particle size has negligible influence on yield strength, while ultimate tensile strength and ductility gradually decrease with increasing particle size. Reduced specific wear rate was observed when particle size increases, most likely because of the evolution of the surface topography during sliding where the wear of matrix is protected when particles are large.