Al Composite Materials Research Articles

Ultra‐high bonding strength of carbon fiber–doped polyamide–aluminum alloy composite structure achieved by changing crystallinity

AbstractLightweight and high‐strength polymer–metal hybrid structures are favored for reducing material and energy consumption. In this study, carbon fiber‐reinforced polyamide 6 (CFPA) composite materials were prepared through melt blending, and 30 wt% CFPA exhibited the highest shear strength and lowest shrinkage rate among other carbon fiber contents. With pretreatments of anodizing and etching treatment, injection molded direct joining was employed to create polyamide 6 (PA)/CFPA–Aluminum alloy (Al) composites. The impacts of the injection temperature and speed on the bonding strength of the PA/CFPA–Al composite materials were investigated. The characterization results confirmed that carbon fiber doping reduces the coefficient of linear thermal expansion (CLTE) and enhances crystallization ability of PA. The higher injection temperatures and lower injection speed significantly increase the crystallinity of PA and the infiltration of the molten polymer into the nanoporous anodic aluminum oxide films. When the injection temperature was 270°C and the speed was 6 mm/s, the bonding strength of the PA–Al hybrid structure reached a maximum of 36.6 MPa. When the injection temperature was 300°C, the bonding strength of the CFPA–Al hybrid structure reached a maximum of 40.8 MPa. Adhesive parts with high shear bonding strength are critical to satisfying engineering requirements and have significant potential, particularly in polymer–metal composite structures. The polymer‐metal hybrid structure can meet the high interfacial bonding strength required in most engineering applications.Highlights Injection temperature and speed in IMDJ affect PA crystallinity. Carbon fiber doping reduces the CLTE of PA and increases the shear strength. High temperatures and low injection speeds are beneficial to adhesives. The bonding strength of PA–Al reached a maximum of 36.6 MPa. The bonding strength of CFPA–Al reached a maximum of 40.8 MPa.

Development of novel cellular copper–aluminum composite materials: The advantage of powder metallurgy and mechanical milling approach for lighter heat exchanger

Herein, a precise approach for the fabrication of cellular Cu–Al composite materials with favorable physical properties was developed. Hence, the obvious characteristics of cellular Cu-based materials were markedly improved by the incorporation of light metal of Al in Cu matrix using a ball milling method and polyethylene glycol as a space holder. Porous copper-aluminum composite materials were manufactured with uniform pore size distribution with porosity percentages of 37%–88% and pore sizes within the range of 50–200 μm. Two prominent types of Cu–Al cellular composite materials were produced. The first type showed an open-cell microstructure with polyhedral pores, high volume porosity of 88%, yield strength of 0.5 MPa, superior thermal conductivity (42 W/m.k), and outstanding electrical conductivity (0.057 × 10 8 (Ω−1. m−1)). The second type with a semi-open cell microstructure and spherical pore shape exhibited a favorable yield strength of 42 MPa, a good elastic modulus of 183 MPa, and an acceptable ductility of 35%. This process contributes to the development of cellular copper-based materials used in industrial applications such as filters, fuel cells, and heat exchangers. This research also lays the groundwork for the production of different types of cellular composite materials with varied characteristics and applications.

Поглотители электромагнитного излучения СВЧ-диапазона на основе частиц Fe и Fe – Al, полученные в поле вращающихся магнитных диполей

The purpose of the work is to obtain microwave absorber materials based on Fe – Al particles and to study its absorbing characteristics. Composite materials consisting of Fe, Fe – Al particles and a paraffin matrix were obtained by rotational magnetic field method. The mechanism of the field of rotational magnetic dipoles usage for Fe particles coating with Al nanoparticles and further composite material synthesis was described. Microstructure, mechanical, magnetic and dielectric properties and parameters of microwave absorption of obtained composite materials were investigate. Magnetic and dielectric permittivity in the frequency range 8 – 12 GHz were obtained. The influence of the field of rotational magnetic dipoles in combination with Al nanoparticles allows to obtain more durable structure in comparison with composite materials without Al nanoparticles. It was found that composite materials have a good radio-absorbing properties in the studied frequency range. The maximal value of S21 = –27,9 dB was obtained on 12 GHz frequency for a Fe – Al composite material with the field of rotational magnetic dipoles application.

THE EFFECT OF ANNEALING AND COLD FORGING ON MICROSTRUCTURE AND HARDNESS PROPERTIES OF Al-SiC COMPOSITE : A PRELIMINARY STUDY

THE EFFECT OF ANNEALING AND COLD FORGING ON MICROSTRUCTURE AND HARDNESS PROPERTIES OF AL-SIC COMPOSITE: A PRELIMINARY STUDY. Aluminium Metal Matrix Composites (AMMCs) are one of the exciting materials that have an extensive function in various applications. By utilizing reinforcement in the fabrication process, Al composites can produce superior properties such as high strength, good fracture resistance, and of course, lightweight. Therefore, many studies are interested in revealing the characteristics of Al composite materials through various methods and variations of reinforcement. This research is a preliminary study with a scope of work, including observing the effects of annealing and cold forging processes on the microstructure morphology and hardness properties of SiC nano-ceramic reinforced Al composites. The aluminium used in this study is a 7xxx series aluminium alloy. The fabrication process was carried out by stir-squeeze casting method. Microstructure analysis was conducted by optical microscopy and Scanning Electron Microscopy (SEM) equipped with Emission Dispersion Spectroscopy (EDS). The hardness properties of the Al-SiC composite were examined by micro Vickers hardness testing. This research reported that the annealing process influences the grain refinement and hardness properties of the Al-SiC composite. The sample experienced to cold forging has to improve the hardness value. Increasing hardness by forging after anneal may introduce due to the grain compression effect of the dislocation mechanism. Comprehensive research is required to find out other potentials of Al-SiC composite materials. Keywords: Al-SiC composite, annealing temperature, cold forging, hardness, microstructure.

Investigation of Radiation Attenuation Properties of Al-Cu Matrix Composites Reinforced by Different Amount of B4C Particles

In recent years, B 4 C particle reinforced Al matrix composite materials have been excessively used for gamma and neutron shielding regarding their neutron absorption and lightweight. In this paper, linear and mass attenuation coefficients using 80 keV, 356 keV, 137Cs (662 keV), 60Co (1173 keV,1332 keV) and 2000 keV(high energy) gamma energies for B 4 C (5-15 wt%) particle-reinforced Alumix 13 and Alumix 231 (which contains special alloy elements such as Cu and Mg) aluminum matrix composites were theoretically calculated with XCOM platform. Pair production, coherent scattering, photoelectric absorption and incoherent scattering processes besides the total attenuation coefficients for B4C (5-15 wt%) particle-reinforced Alumix 13 and Alumix 231 matrix composite materials were evaluated separately. On the other hand, half-value thickness (HVL) values and one-tenth thickness values (TVL) were also calculated to evaluate the radiation shielding effectiveness of this material excluding coherent scattering values that are frequently used in gamma ray transport theory as well as the total attenuation coefficients. Gamma attenuation curves for Al composite materials against 80 keV, 356 keV, 137Cs (662 keV), 60Co (1173 keV, 1332 keV) and 2000 keV (high energy) gamma energies were theoretically calculated and plotted for B 4 C (5-15 wt%) particle-reinforced Alumix 13 and Alumix 231 matrix composite materials. According to the obtained results for this material, radiation attenuation properties and the ability of shielding of materials were investigated. Therefore, this study is original from a variety of aspects, and its results may be used not only in nuclear technology but also in other technologies such as nano and space technology.

The Effect of Charge Grit on Impact Strength and Damping Characteristics of BN–Al Composite Materials

Abstract—The dependence of the impact strength and damping characteristics of сBN–Al composite materials on the specific surface (grain size) of cubic boron nitride powders has been investigated. The correlation between the damping characteristics of the composite material and its phase composition has been established. The dependence of the phase composition of the material on the specific surface of the powdered cBN component has been demonstrated. Composite materials with a biphasic structure and the highest density and hardness possible for this structure had the maximal impact strength.

Highly efficient capture of rubidium ion by a novel HS-Fe3O4@MIL-53(Al) composite material

A general synthetic strategy for HS-Fe3O4@MIL-53(Al) adsorbent has been developed in this work. The composite material exhibits an efficient capture performance for rubidium ion due to sulfhydryl group and magnetic Fe3O4 doped in its porous cavity. The results of X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and N2 adsorption–desorption proved that the HS-Fe3O4 was immobilized in the composite material. High Rb+ uptake capacity over the HS-Fe3O4@MIL-53(Al) is attributed to the exchange of acidic protons between the sulfhydryl group and the Rb+. The pseudo-second-order and Freundlich model could make a good description of the adsorption process. The Rb+ sorption selectivity was moderately influenced by any co-ions effect (K+, Na+ and Cs+) due to HS-Fe3O4 doped. These results reveal that our novel composite material might be a promising industrial adsorbent for Rb+ capture.

Development of Hot-Pressing Technology for Production of Aluminum-Based Metal-Matrix Composite Materials

A hot-pressing technology for producing aluminum-based metal-matrix composite materials used to manufacture liquid-cooled base plates of electronic modules of active phased antenna arrays (APAA) was developed and tested. The technology involves the following operations: mixing of the starting components, adding of a binder, forming of blanks, hot pressing of the blanks, sintering in a controlled atmosphere, grinding of the sintered blanks, cutting of the blanks to size, coating, and controlling of the material parameters. The curves of the density of SiC–Al composite material versus the isothermal-holding time and the compaction pressure are plotted. It is established that combining hexagonal silicon carbide (6H α-SiC) and aluminum alloy with a silicon content of 7–12%, it is possible to obtain a SiC–Al composite with a thermal conductivity of up to 240 W/(m·K).

Atomic and molecular LIBS spectra of Al alloys and composite materials for nanosecond and microsecond excitation

Spectral investigations in the UV-VIS range of selected Al alloys and composites, used in the construction of armament components as well as drones, were performed using LIBS technique. Two Nd:YAG lasers were applied: a short pulse 4 ns 60 mJ laser and a long pulse 200/400 (up to 1000) us (~ 2/4 up to 10 J) laser. In experiments with a short laser pulse only atomic spectra were observed while for long pulses, also molecular transitions have been recorded. Electron temperatures of created plasma were found on the base of Boltzmann law. Temperatures are clearly higher for short pulse excitation. Full Text: PDF ReferencesA. Miziolek, V. Palleschi and I. Schechter, Laser-Induced Breakdown Spectroscopy (Cambridge, Cambridge University Press 2006). CrossRef M. Sabsabi and P. Cielo, "Quantitative Analysis of Aluminum Alloys by Laser-Induced Breakdown Spectroscopy and Plasma Characterization", Appl. Spectrosc. 49, 499 (1995). CrossRef D.L. Death, A.P. Cunningham, and L.J. Pollard, "Multi-element analysis of iron ore pellets by Laser-induced Breakdown Spectroscopy and Principal Components Regression", Spectrochim. Acta B, 63, 763 (2008). CrossRef S. Laville, M. Sabsabi and F. Doucet, "Multi-elemental analysis of solidified mineral melt samples by Laser-Induced Breakdown Spectroscopy coupled with a linear multivariate calibration", Spectrochim. Acta B, 62, 1557 (2007), CrossRef D.M. Surmick, C.G, Parigger, "Aluminum Monoxide Emission Measurements in a Laser-Induced Plasma", Applied Spectroscopy, 2015, V.68, No.9, P.992-996. CrossRef J.B. Sirven, B. Bousquet, L. Canioni and L. Sarger,"Laser-Induced Breakdown Spectroscopy of Composite Samples: Comparison of Advanced Chemometrics Methods", Anal. Chem. 78, 1462 (2006). CrossRef E.J. Judge, G. Heck, E.B. Cerkez and R. J. Levis, "Discrimination of Composite Graphite Samples Using Remote Filament-Induced Breakdown Spectroscopy", Anal. Chem. 81, 2658 (2009). CrossRef L.M. Cabalin and J.J. Laserna, "Experimental determination of laser induced breakdown thresholds of metals under nanosecond Q-switched laser operation", Spectrochim. Acta B, 53, 723 (1998). CrossRef T.A. Labutin, A.M. Popov, V.N. Lednev and N.B. Zorov, "Correlation between properties of a solid sample and laser-induced plasma parameters", Spectrochim. Acta B, 64, 938 (2009). CrossRef J.S. Cowpe, R.D. Moorehead, D. Moser, J.S. Astin, and S. Karthikeyan, "Hardness determination of bio-ceramics using Laser-Induced Breakdown Spectroscopy", Spectrochim. Acta B, 66, 290 (2011). CrossRef G. Cristoforetti, , S. Legnaioli, V. Palleschi, A. Salvetti, and E. Tognoni, "Effect of target composition on the emission enhancement observed in Double-Pulse Laser-Induced Breakdown Spectroscopy", Spectrochim. Acta B, 63, 312 (2008). CrossRef

Microstructure and phases constitution of Cr3C2/Ni3Al composites prepared by hot isostatic pressing (HIP)

The Cr3Cj/Ni3Al composite materials were prepared by hot isostatic pressing (HIP) at 1160°C and 100MPa. Microstructure and phases constitution of the composite materials were investigated. The results indicate that the original Cr3C2 particle firstly dissolves into Cr and C atoms and then diffuses into the matrix. During the cooling process, the dissolved Cr and C atoms transformed into a stable Cr7C3 structure. Also, an uphill diffusion phenomenon is observed for Fe element from the matrix to the Cr7C3 carbide phase, which is attributed to the easy formation of stable carbides of Fe element in Ni3Al alloy with C element. And, the Fe atoms substitute a part of Cr atoms in Cr7C3 carbides and form a diffusion phase with M7 C3 (M for Cr, Fe) structure. When the original Cr3Q2 particles are large, it cannot be completely dissolved during the high temperature period. The undissolved core of Cr3C2 particles still remain the Cr3C2 structure after the cooling process. The Cr3C2/Ni3 Al composite materials are composed of Cr3C2 hard core phase, M7C3 diffusion phase and ?-Ni3Al matrix material phase. The Cr3C2 hard core phase and the ?'-Ni3Al matrix created a good diffusion bonding by the formed M7C3 diffusion phase. Therefore, the Cr3C2 particle on the worn surface does not peel off and the groove is interrupted around the chromium carbides during the wear test, resulting in significantly improved wear resistance of Cr3C2/Ni3Al composites.

Pressure Sintering, Structure and Some Properties of SiC–Al Composite Materials

The pressure sintering of silicon carbide powder mixtures with 15, 30, and 50 wt.% aluminum prepared by grinding in a planetary mill is investigated. A mechanochemical synthesis of new Aland Si-based phases with Fe and O admixtures during grinding is discovered. Further pressure sintering results in the formation of a fine-grained (1–2 μm) structure consisting of SiC basic phase, Al and Si oxides as well as Al oxysilicide. Oxygen and carbon atoms are uniformly distributed, while Al and Si atoms are concentrated in the structural components of the composites. According to the analysis of the compaction kinetics of the composites during nonisothermal pressure sintering, it is found out that their volume flows are controlled by a combination of non-linear creep and linear viscous flow mechanisms, providing the accommodation of the structure of forming phases. These flows are characterized by relatively low activation energies, which can be attributed to the movement of vacancies when lattice and grain-boundary diffusion run. With the exception of SiC–50% Al sintered at 1800°C, the studied materials are characterized by brittle fracture. The hardness and fracture toughness values of SiC–Al sintered composites are in agreement with literature data.

Microstructure of a complex Nb–Si-based alloy and its behavior during high-temperature oxidation

A in-situ composite Nb–Si–Ti–Hf–Cr–Mo–Al composite material alloyed with yttrium and zirconium is studied. The evolution of the structure–phase state of the alloy during oxidation under dynamic and isothermal conditions is considered on samples prepared by vacuum remelting and directional solidification. The phase composition and the microstructure of the alloy are examined by the methods of physico-chemical analysis, and the distribution of alloying elements in initial samples and the products of oxidation is estimated. Thermogravimetric experiments are performed on powders and compacted samples during continuous (in the range 25–1400°C) and isothermal (at 900 and 1100°C) heating in air. The directional solidification of an Nb–Si–Ti–Al–Hf–Cr–Mo–Zr–Y is found to cause the formation of an ultradispersed eutectic consisting of α-Nbss and γ-Nb5Si3ss cells. The as-cast sample prepared by vacuum remelting has a dendritic structure and contains Nb3Si apart from these phases. Oxidation leads to the formation of a double oxide layer and an inner oxidation zone, which retain the two-phase microstructure and the ratio of alloying elements that are characteristic of the initial alloy. Diffusion redistribution is only detected for molybdenum. The cyclicity of heating at the initial stage of oxidation weakly influences the oxidation resistance of the alloy.

The optimization of development process of petrol-gas stations network with the purpose to increase energy efficiency

Development of petrol/gas stations network requires a complex approach to the assessment of environmental impact. The use of appropriate indicators according DPSIR methodology enables optimization of processes at oil/gas stations and increase energy efficiency. Use of renewable energy and new insulating materials has great importance to reduce energy consumption for heating of petrol/gas stations buildings. As a replacement styropor and styrodur (for added insulation of walls and floors) is much more efficient to use blocks of innovative insulating materials in the construction of new facilities. Widespread application of renewable energy and thermal insulation materials in buildings of oil/gas stations, reducing electricity consumption by using energy-saving LED technology, as well as savings in transportation fuels reducing the weight of tankers using Al alloys and composite materials are the basic methods of increasing energy efficiency. The use of Al alloys in tankers and reservoirs design conductive to increase corrosion resistance.

Fabrication of WS<sub>2</sub>-Dispersed Al Composite Material by Compression Shearing Method at Room Temperature

In this study, WS2-dispersed Al composite material was fabricated by Compression Shearing Method at Room Temperature, using various WS2 content ratios. The mechanical and friction properties of the WS2-dispersed Al composites were measured. As a result, the density measurements showed that the compacted WS2-dispersed aluminum composite had a relative density of 95 to 99%. Tensile strength of WS2-dispersed Al has 200 MPa. The friction coefficient of Al/0.5vol.%WS2 was 0.14, a reduction of 83%, in comparison with the 1.0 friction coefficient of the pure Al matrix material. The addition of WS2 to the matrix systems used reduced the friction coefficient. Therefore, WS2-dispersed Al composite material is useful for maintenance-free material of slide member.

Research Progress of High Speed Cutting for SiCp_Al Composite Materials

Summarized the research and development of high speed machining of SiCp/Al composites. Emphasized the research status of high speed cutting of SiCp/Al composite materials, including machined surface quality and tool wear condition. Machined surface quality contains surface roughness and surface defects. The tool wear conditions are different because of different types of cutting tools, but the wear of the rake face, the rear face and the cutting edge are all involved.

Compressive behavior of CNT-reinforced aluminum composites using molecular dynamics

Abstract This paper presents a Molecular Dynamics (MD) study on the characterization of the compressive behavior of an aluminum (Al) material reinforced with carbon nanotubes (CNTs). Firstly, a detailed literature review of recent experimental and numerical works dedicated to the characterization and mechanical enhancement of CNT–Al composites is presented. Then, the paper describes a computational approach based on MD simulations used to analyze the mechanical behavior of the CNT–Al composite material under compression. Finally, the paper presents and discusses several results that comprise (i) curves relating the energies (total, Al, CNT, interface) with the imposed axial shortening displacement, (ii) plots of deformed shapes and failure modes of CNT–Al specimen and (iii) curves relating the acting stress with the imposed strain. In this study, we adopted two limit cases for bonding between the CNT and Al matrix, one in which the displacements are imposed to the Al atoms (case A) and another in which displacements are imposed to both Al and C atoms (case B). In comparison with pure Al, the Young’s modulus increases about 50% in case A and 100% in case B. These increases are not only due to the CNT intrinsic stiffness but also to the interface slip stresses, which are about 16 MPa (case A) and 75 MPa (case B). In opposition, it is seen that both yield stress and yield strain do not increase. This evidence is mostly due to premature failure of the CNT–Al composite due to CNT local buckling. This study not only confirms previous results obtained by other researchers (e.g. Laha et al. [1] ) but also provides some understanding on the compressive behavior of CNT-based composites, which might be different to standard tensile behavior.

Si‐Composite Anode for Lithium‐Ion Batteries with High Initial Coulombic Efficiency

An ode to anodes: Si–Fe–Al composite materials are synthesized by high-energy ball-milling as anodes for lithium-ion batteries. The as-prepared Si composite anodes deliver high capacity values, high Coulombic efficiencies, and good cycle performance. The performance is mainly attributed to the unique structure of elemental Si uniformly distributed amongst inactive intermetallic phases.

The effect of mixed mode I/II on the fracture toughness and fracture behavior of nano-structured metal matrix composites

A nano-structured Al89Gd7Ni3Fe1 composite alloy was made from extruding its atomized amorphous powder at different extrusion ratios (ER). The effects of changing the notch radius from fatigue pre-crack to 100μm on mode I fracture toughness were studied at different test temperatures (e.g., 298K and 498K). The effects of mixed mode (I/II) loading using different offset ratios were also studied at these temperatures. Increasing the test temperature showed a significant effect on the fracture toughness for mode I and mixed mode I/II conditions. Fracture surfaces were examined to reveal the nature of failure of such nano-structured Al composite materials at these loading conditions.

Novel wire bond material for advanced power module packages

Novel heavy wire bonds made of an Al and Cu composite material are introduced. Besides the excellent mechanical and electrical properties an Al-clad Cu wire bond (Al/Cu) provides outstanding stability under cyclic load. To evaluate the potential of the novel material two different types of Al/Cu wires were investigated with respect to processability, ampacity and power cycling capability. In contrast to other advanced wire bond materials no change in the metallization of the chip surface is necessary to establish a stable bonding process.

Microstructure and Corrosion Resistance of <i>In Situ</i> Al<sub>0.983</sub>Cr<sub>0.017</sub>/Al Composites

In situ Al0.983Cr0.017 intermetallic compounds reinforced aluminum matrix composite was fabricated by the mechanical stirring casting method in this paper. In addition, microstructure and corrosion resistance of composite was investigated by XRD and SEM. The results show that the Al0.983Cr0.017 intermetallic compounds reinforcement distribute in the matrix uniformly. The clean interface between reinforcement and matrix has good interfacial bond. The corrosion resistance of Al0.983Cr0.017/Al composite materials presented a U-shaped curve, the best corrosion resistance present in the composite with 12% volume fraction reinforcement. The Al0.983Cr0.017 has a high corrosion resistance, which promoted the nucleation of pitting. Furthermore, the reinforcement interrupt the continuity of the matrix, inhibits the further expansion of pitting, which increases the corrosion resistance of composites.