Fiber Reinforced Aluminum Composites Research Articles

Increasing joint strength by achieving carbon fibers’ continuity with ultrasonic assistance during soldering Cf/Al using ZnAl

Ultrasonic assistance was utilized during the soldering of carbon fiber-reinforced aluminum composites (Cf/Al) using ZnAl solder to enhance joint strength. The results indicated that carbon fibers migrated into the joint seam after Al substrate was eroded and the solder was expelled, effectively maintaining the continuity of the carbon fibers. A joint fully reinforced by carbon fibers was achieved with an ultrasonic application time of 60 s. Transmission electron microscopy revealed rapid wetting of the carbon fibers facilitated by ultrasound, characterized by an amorphous/nanocrystalline interface. The maximum joint strength reached 23.5 MPa, which is equivalent to 77.5 % of the Cf/Al.

Micromechanical modeling of longitudinal compression behavior and failure mechanism of unidirectional carbon fiber reinforced aluminum composites involving initial fiber misalignment

AbstractA micromechanical model with realistic initial fiber misalignment (IFM) was developed to simulate the longitudinal compression behavior of unidirectional carbon fiber/aluminum composites. The matrix and fiber were modeled using ductile damage law and brittle fracture model, respectively. The interfacial properties were firstly determined by the single‐fiber push‐out and transverse tensile tests, and the cohesive zone model was adopted to capture the interfacial behavior. The calculated compressive response curve is in alignment with the experimental data. Compression failure can be attributed to fiber kinking, possibly triggered by the matrix shear damage. The increase of IFM angle makes the failure mode being transformed from fiber crushing to fiber kinking, along with a significant decrease in compressive strength. With the fiber content increasing, the compressive strength increases first and then decreases, while the compressive modulus increases monotonically. Increasing interfacial strength significantly improves the compressive strength, but this is limited by the matrix properties.

Ultrarapid soldering Cf/Al by inactive solder by ultrasonic assistance

Ultrasonic vibration was applied when soldering carbon fiber-reinforced aluminum composites (Cf/Al) in this work. The effects of ultrasonic action time on joint formation, carbon fiber distribution, and mechanical properties of the joints were studied. Results show that, with the assistance of ultrasonic vibration, inactive solder can wet the carbon fiber within dozens of seconds at low temperature (250 °C). Short ultrasonic action time leads to minor erosion of aluminum substrate, thereby restricting the movement of carbon fibers into joint. Extensive erosion of the aluminum occurs with prolonged ultrasonic action time. A uniform distribution of carbon fibers in joint is achieved at 60 s. Wetting of carbon fiber is characterized by amorphous-nanocrystalline oxides on its surface, which can be attributed to the elevated temperature and pressure induced by the cavitation of the solder. Extending ultrasonic time enhances the hardness and the shear strength of the joint. The failure cracks propagate through the substrate when ultrasonic time exceeds 15 s. This work provides referential value when soldering materials with low surface energies.

3D printed aluminum matrix composites with well-defined ordered structures of shear-induced aligned carbon fibers

Carbon fiber reinforced aluminum composites with ordered architectures of shear-induced aligned carbon fibers were fabricated by 3D printing. The microstructures of the printed and sintered samples and mechanical properties of the composites were investigated. Carbon fibers and aluminum powder were bonded together with resin. The spatial arrangement of the carbon fibers was fixed in the aluminum matrix by shear-induced alignment in the 3D printing process. As a result, the elongation of the composites with a parallel arrangement of aligned fibers and the impact toughness of the composites with an orthogonal arrangement were 0.82% and 0.41 ​J/cm 2 , respectively, about 0.4 and 0.8 times higher than that of the random arrangement.

Electrical, Thermal, and Mechanical Characterization of Hot Coined Carbon Fiber Reinforced Pure Aluminium Composites

Poor interfacial structure and severe agglomerations of carbon fiber (CF) are significant problems that face carbon fiber reinforced aluminium (CF/Al) composites. Thus, CF was surface modified with nano copper particles (Cu) to overcome these problems. Two groups of CF/Al composites (uncoated and coated) at different weight percentages of reinforcement (0, 5, 10, 15, and 20) were fabricated using the planetary ball milling method and then uniaxially hot coined at 550 ℃ under 700 MPa. The results showed that CF refined the crystallite size of the Al matrix, and no {mathrm{Al}}_{4}{mathrm{C}}_{3} or {mathrm{Al}}_{2}mathrm{Cu} were detected in XRD patterns. The density and thermal expansion of composites reduced with increasing CF percentage in all samples. The electrical and thermal conductivities are improved up to 10 wt% of uncoated reinforcement and 15 wt% of coated one. The mechanical test results revealed that by increasing CF, the compressive strength of composites decreased while the wear properties improved for both groups. Cu deposition on CF improved the bonding between reinforcement and matrix, producing composites with better interfacial bonding, fewer agglomerations and porosity, and higher values of the properties of the composites.Graphic Preparation and characterization of carbon fiber reinforced aluminium composites by hot coining technique

Thermal response of the two-directional high-thermal-conductive carbon fiber reinforced aluminum composites with low interface damage by a vacuum hot pressure diffusion method

A two directional high thermal conductive carbon fiber reinforced aluminum matrix composite with low interface damage is prepared by a vacuum hot-pressure diffusion method using the mesophase-pitch-based carbon fiber (CFMP) cloth as fast heat conduction channels. The fiber/matrix interface is composed of an amorphous gradient transition layer between aluminum matrix and CFMP rather than Al4C3 interface phase, thus endowing the continuous heat conduction channels in the composite. The composites deliver the high thermal conductivity of 305.5 W∙m−1∙K−1 in the X (Y) direction and the low volume density of only 2.53 g∙cm−3 when the fiber volume fraction reaches 30 vol%. The high thermal conductivity of the composite is attributed to the highly oriented fast heat transfer effect of the CFMP, the isotropic heat transfer effect of the aluminum matrix and the low-damage CFMP/aluminum interface. This study opens a new avenue to design and select the high thermal conductivity and lightweight thermal management materials for the aerospace field.

An investigation on microstructure and mechanical behaviour of copper-nickel coated carbon fibre reinforced aluminium composites

In the present investigation, mechanical, corrosion and fatigue characterization is performed on the fabricated aluminium metal matrix composite (AMMC), by reinforcing nickel (Ni) and copper (Cu) coated 4% carbon fibre (CF) in aluminium alloy (AA6026) matrix. With a view of enhancing the strength of the aluminium alloy, an optimal percentage (4 wt%) of CFs is reinforced; as CFs cannot be directly reinforced in the aluminium matrix due to poor wettability, CFs are coated with Ni and Cu using electroless plating technique for better wettability and bonding between reinforcement and matrix. Properties of the cast alloy and coated CF reinforced composite are compared and the composite with better properties is identified as 4% Cu coated CFs reinforced AMMC. When compared with as-cast alloy and Ni coated CF reinforced composite, the tensile strength of Cu coated CFs composite was higher by 15.36% and 2.55%. Similarly, micro-Vickers hardness was improved by 7.61% and 3.09%, impact strength by 19.61% and 3.39%, flexural strength by 87.50% and 15.38%. The corrosion rate (mils/year) was reduced with incorporation of 4% Cu coated CFs in AA6026 by 59.72% and 23.23% as compared with as-cast and Ni coated CF reinforced composition.

Micromechanics analysis on the microscopic damage mechanism and mechanical behavior of graphite fiber-reinforced aluminum composites under transverse tension loading

In this paper, the transverse tensile behavior and microscopic damage evolution of graphite fiber-reinforced aluminum composites were investigated by numerical and experimental methods. Micromechanical models based on realistic and assumptive fiber arrangements were established. In these models, the progressive damage procedure of the matrix alloy and the interface was incorporated. The validity of the models was assessed by comparing the predicted stress-strain curves with the experimental ones. The microscopic damage behavior of the matrix alloy and the interface was revealed and its contributions to macroscopic mechanical responses were analyzed in detail. The interaction of different damage mechanisms was further discussed on the basis of numerical and experimental results. The influences of interface, matrix alloy, and fiber volume fraction on damage evolution and mechanical behaviors were parametrically studied on the basis of the verified micromechanical model to provide insights into the damage mechanisms of the composites.

Micromechanical Modeling of Damage Evolution and Mechanical Behaviors of CF/Al Composites under Transverse and Longitudinal Tensile Loadings.

This paper investigates the progressive damage and failure behavior of unidirectional graphite fiber-reinforced aluminum composites (CF/Al composites) under transverse and longitudinal tensile loadings. Micromechanical finite element analyses are carried out using different assumptions regarding fiber, matrix alloy, and interface properties. The validity of these numerical analyses is examined by comparing the predicted stress-strain curves with the experimental data measured under transverse and longitudinal tensile loadings. Assuming a perfect interface, the transverse tensile strength is overestimated by more than 180% and the transverse fracture induced by fiber failure is unrealistic based on the experimental observations. In fact, the simulation and experiment results indicate that the interface debonding arising from the matrix alloy failure dominates the transverse fracture, and the influence of matrix alloy properties on the mechanical behavior is inconspicuous. In the case of longitudinal tensile testing, however, the characteristic of interface bonding has no significant effect on the macroscopic mechanical response due to the low in-situ strength of the fibers. It is demonstrated that ultimate longitudinal fracture is mainly controlled by fiber failure mechanisms, which is confirmed by the fracture morphology of the tensile samples.

Effect of interfacial microstructure on the thermal-mechanical properties of mesophase pitch-based carbon fiber reinforced aluminum composites

Four unidirectional carbon fiber (67.9%–70.0% volume fraction) reinforced aluminum composites (P100/1199, P100/6063, P120/1199, and P120/6063) were fabricated by pressure infiltration and thermo-mechanical properties of these composites were investigated. We found interfacial microstructures, especially free of carbide, precipitations and interfacial gaps, are important for the properties of the composites. With proper addition of Mg and Si element, P100/6063 composite possessed moderate interface. Thus, thermal conductivity (TC), bending strength and elastic modulus of that were improved prominently. TC along fiber direction of P100/6063 was (391±1)W/mK, which was close to 95% of the role of mixtures (ROM) model. The coefficient of thermal expansion values (CTE) along fiber direction of all the specimens varied between −1×10−6/K and 1×10−6/K. The bending strength and the elastic modulus of P100/6063 composite exhibited a 31.6% and 14.3% increase respectively in comparison to those of P100/1199 composite. High TC, low CTE value, and excellent mechanical properties make this material promising for microelectronic chips production.

Investigation on mechanical properties and failure mechanisms of basalt fiber reinforced aluminum matrix composites under different loading conditions

Basalt fiber reinforced aluminum matrix composites with different fiber contents (i.e. 0 wt%, 10 wt%, 30 wt% and 50 wt%) were prepared by hot-press sintering. Microstructure analysis indicates that basalt fibers are uniformly distributed in 10% basalt fiber reinforced aluminum matrix composite. The interfacial bonding between basalt fibers and aluminum matrix is good, and there is no interface reaction between basalt fiber and aluminum matrix. Quasi-static tensile, quasi-static compression and dynamic compression properties of basalt fiber reinforced aluminum composites were studied, and the influences of basalt fiber content on mechanical properties were discussed. Meanwhile, the failure mechanisms of basalt fiber reinforced aluminum matrix composites with different fiber content were analyzed.

Improved mechanical properties in friction stir processed carbon fiber reinforced aluminum composites

Improved mechanical properties in friction stir processed carbon fiber reinforced aluminum composites

Thermal conductivity and mechanical properties of pitch-based carbon fibre reinforced aluminium composites fabricated by squeeze casting

Pure aluminium and high-silicon aluminium alloy were reinforced with the discontinuous pitch-based carbon fibres by squeeze casting, then the thermal conductivity and the mechanical properties of the composites were investigated. Optical microscopy revealed that the fibres were in a random planar arrangement, and the transmission electron microscopy revealed that there is no interfacial reaction between the matrices and the fibres. The random planar arrangement of the fibres leads to the anisotropy of the composite. The fibre-reinforcement increased the thermal conductivity in the parallel direction for both pure aluminium and its alloy matrices, while the thermal conductivity decreased in the vertical direction. The increase in the elastic modulus by the reinforcement was not observed for both matrices. The proof stress of the pure aluminium increased by the reinforcement especially in the parallel direction, while that of the high-silicon alloy decreased by the reinforcement.

Tribological properties of carbon fiber-reinforced aluminum composites processed by spark plasma sintering

Tribological properties of carbon fiber-reinforced aluminum composites processed by spark plasma sintering

Analyzing the impact of microstructural defects on the failure response of ceramic fiber reinforced aluminum composites

The computational homogenization technique is employed to investigate the effect of pre-existing microstructural voids on the failure response of a ceramic fiber reinforced aluminum composite subjected to loads in transverse to the fiber direction. Automated numerical simulations are carried out using a hierarchical interface-enriched finite element method (HIFEM), which enables the use of simple structured meshes for creating the discretized model. The HIFEM is integrated with a new microstructure quantification algorithm relying on the Random Sequential Adsorption (RSA) and Non-Uniform Rational B-Splines (NURBS) to create realistic periodic unit cells of the composite based on imaging data. A strain-driven homogenization problem is then solved at the microscale to simulate the damage evolution in the aluminum matrix using the Lemaitre elasto-plastic damage model. Six virtual models of the composite microstructure with varying volume fractions and spatial distributions of pre-existing voids are analyzed to determine their failure responses subject to macroscopic normal and shear strains. The outcomes of this study indicate that although for the latter type of loading the impact of small volume fractions of voids on the failure response is negligible, their presence significantly deteriorates the composite mechanical strength subject to uniaxial and equi-biaxial macroscopic normal strains.

Structure and properties of squeeze infiltrated zirconia grade-aluminosilicate short fiber reinforced aluminum composites

Squeeze infiltration process is successfully adopted to develop Al6061 metal matrix composite reinforced with zirconia grade aluminosilicate fiber using 15 and 20 vol% preforms. Composites microstructure depicts uniform distribution of fiber throughout the matrix with the elimination of preform breakage, porosities, and shrinkage. TEM observation shows the formation of Al2O3 at the interface, which controls the chemical interaction between the matrix and the fiber. Infiltrated composite shows enhanced wear resistance behavior compared to that of base alloy, and it improves with the increase in volume fraction of the reinforcement. However, sliding speed overcomes the volume fraction concept in improving the wear resistance of the composite by the quick formation of mechanically mixed layer (MML) at increased sliding speed. The tensile and impact strength of the base alloy is slightly higher than that of the composite due to its ductile nature. Incorporation of fiber in the matrix improves the CTE, hardness, compression and corrosion properties of the composite.

Fabrication of novel fiber reinforced aluminum composites by friction stir processing

In this study, chopped and attrition milled high strength carbon, E-glass, and S-glass fibers have been used as the reinforcing agents in an aluminum alloy (Al1100) considered as the matrix. The Surface Metal Matrix Composites (SMMCs) then are produced by Friction Stir Processing (FSP). Tensile and micro-hardness examinations represent a magnificent improvement in the hardness, strength, ductility and toughness for all of the processed samples. Scanning Electron Micrographs reveal a proper distribution of the reinforcements in the matrix and a change in the fracture behavior of the FSPed specimens. The synergetic effects of reinforcing by fibers and Severe Plastic Deformation (SPD) lead to an extra ordinary improvement in the mechanical properties.

Microstructure of a carbon fiber-reinforced aluminum matrix composite fabricated by spark plasma sintering in various pulse conditions

Carbon fiber-reinforced aluminum composites were produced by spark plasma sintering in various pulse conditions. The pulse condition of spark plasma sintering affected the aluminum particle boundaries and aluminum/carbon fiber interfaces; the different fracture morphologies of aluminum oxide were observed on aluminum particles and interfacial aluminum carbide formation. We demonstrated the control of the quantity of aluminum carbide crystals by the alteration of pulse conditions. Finally, we propose the mechanism of local temperature increase in the spark plasma sintering process.

Thermal Elastic Stress Analysis of Steel Fiber Reinforced Aluminum Composites

Thermal Elastic Stress Analysis of Steel Fiber Reinforced Aluminum Composites

Fabrication of Short Graphite Fiber Preforms for Liquid Metal Infiltration

Starch-based and paraffin wax (PW)-based binders were used to fabricate short graphite fiber preforms for liquid metal infiltration. The effects of different binder components and debinding process parameters on the properties of short graphite fiber preforms were investigated. The results indicate that the graphite fiber preforms with appropriate porosity of 58-62% and relatively high compressive strength of about 2-3 MPa can be made by starch-based and PW-based binders. The graphite fiber preforms made from the PW-based binder exhibit higher compressive strength than that of the starch-based binder. Graphite fiber reinforced aluminum composites fabricated by utilizing these preforms through vacuum pressure infiltration have relatively high density of 98.5% and thermal conductivity of 186.3 W/m K, proving the applicability of the prepared preforms for liquid metal infiltration.