Fiber Reinforced Aluminum Matrix Composites Research Articles

Continuous Casting Preparation Process of Helical Fiber-Reinforced Metal Matrix Composites

To improve the strength of the metal while maintaining good plasticity, helical fibers are added to the metal matrix. How to form helical fiber and control its parameters in the preparation process are urgent problems to be solved in the study of helical fiber-reinforced metal matrix composites. In this paper, the continuous casting process of helical fiber-reinforced metal matrix composites was proposed. To reduce the difficulty of the experiment, the formation process of helical fiber on metal matrix and the relationship between the continuous casting process parameters and helical shape fiber parameters were studied by preparing helical carbon fiber-reinforced lead matrix composites with a low-melting-point metal matrix. The results show that this process can produce helical fiber-reinforced metal matrix composite stably and continuously, and the helical shape parameters of the composite can be controlled by changing the process parameters of continuous casting. To further improve the practical application of this process, helical carbon fiber-reinforced aluminum matrix composites were prepared. The test result in terms of mechanical property shows that the tensile strength and elongation of the composite were improved. This indicates that the reinforced phase of the helical structure of the metal matrix composite has higher strength and toughness compared with the matrix metal.

Microstructure and performance of carbon fiber reinforced aluminum matrix composites with molybdenum carbide coating on carbon fibers

In this work, a molybdenum carbide coating on the surface of short carbon fibers prepared using molten salt method was proposed to ameliorate the interfacial bonding and improve the performance of carbon fiber/Al composites. The carbon fiber/Al composites were produced using vacuum hot pressing. The characteristics of molybdenum carbide coating were analyzed. Besides, the microstructures, bending strength and thermal properties of the carbon fiber/Al composites were explored. Furthermore, the interfacial thermal resistance of the composites was investigated in relation to theoretical evaluations derived from the combined Maxwell-Garnett effective medium approach and acoustic mismatch model schemes. The results indicated that a homogeneous Mo2C coating with a thickness of 0.5 μm was obtained by proper molar ratio of carbon fibers, MoO3 and chloride salts mixture and heated at 1000 °C for 60 min. The Mo2C coating greatly enhanced the bond between the aluminum matrix and carbon fiber, leading to improvements in the densification behavior and bending strength of the coated composites. The enhanced thermal properties including improved thermal conductivity and reduced coefficient of thermal expansion (CTE) were also achieved by the Mo2C coating. The in-plane thermal conductivity of 60 vol.% Mo2C-coated carbon fiber/Al composite was 221 W·m−1·K−1 enhanced by 92% compared to that of uncoated composite and the CTE was 6.0 × 10–6 K−1 which was suitable for electronic packaging materials.

High-speed drilling mechanism study of unidirectional CoCrFeNiAl fiber-reinforced aluminum matrix composites

High-speed drilling mechanism study of unidirectional CoCrFeNiAl fiber-reinforced aluminum matrix composites

Research on micro-cutting mechanism of CoCrFeNiAlX high-entropy alloy fiber–reinforced aluminum matrix composites

Research on micro-cutting mechanism of CoCrFeNiAlX high-entropy alloy fiber–reinforced aluminum matrix composites

Rapid ultrasonic soldering Cf/Al at low temperature

Carbon fiber reinforced aluminum matrix composites (Cf/Al) are widely used in various industries. But they are difficult to join because it is hard to realize the wetting and continuity of the carbon fiber in joint. To solve this problem, Cf/Al are joined by ultrasonic soldering in this work. Results show that the Cf/Al can be wetted within 5 s under ultrasonic. Transmission electron microscope result shows that the surface of the wetted carbon fiber is covered by an amorphous-nanocrystalline layer, which is formed due to the high solder velocity, temperature and pressure caused by cavitation. Carbon fibers flow into the solder after the Al matrix is eroded, guaranteeing its continuity in the joint. Limited carbon fibers flow into the joint at low ultrasonic power of 333.3 W, while a fully carbon fiber reinforced composite joint is obtained at 1000 W. The soldered joints have higher strength than the Cf/Al substrate, and its formation mechanism is discussed.

Fabrication of carbon fiber reinforced aluminum matrix composites by inorganic binders

Infiltration is an important issue for unidirectional carbon fiber-reinforced aluminum matrix (CF/Al) composites. In the present study, aluminum dihydrogen phosphate (ADP) and silica sol were used to prepare CF preforms, then CF/Al composites were prepared by simulated horizontal continuous casting. The results showed that silica sol significantly affects the curing process of ADP. When the content of silica sol is 50 % and heated at 500 °C, the product transformed from Al(PO3)3 (cubic system) to an amorphous phase with good thermostability. The mixture binder can fully fill the gaps between CFs, leading to a dense CF preform. The obtained CF/Al composite has a good bonding interface between Al and CFs, without pores or crack defects, and thus shows an obvious enhancement in tensile strength of 64.9 MPa, which is 34.6 % improved compared with that of CPAl. The CF/Al composites also maintained a good electrical conductivity of 56.9 % IACS, similar to that of CPAl.

Effect of interfacial stability on microstructure and properties of carbon fiber reinforced aluminum matrix composites

In order to explore the effect of interface stability between carbon fiber and matrix on the microstructure and properties of carbon fiber reinforced aluminum-matrix (Cf/Al) composites, Cf/Al composites were prepared with different interface coatings (Ni coating, Cu coating and TiC coating). The diffusion model of coatings in Al melt was established and calculated, and the results were compared. The calculation results show that the Ni coating and Cu coating are prone to diffusion in the Al matrix, while the TiC coating can stably exist between the Al matrix and the carbon fiber. The microstructure of Cf/Al composites prepared by different coatings was studied experimentally. When the coating is prone to diffusion in the Al melt, the coating will continuously dissolve and fall off during the preparation of the composite. At this time, due to the instability of the interface, it is easy to produce a large number of Al4C3 brittle phases at the interface. The tensile testing results show that the strength of the Cf/Al composites prepared by stable TiC coating is the highest, and it is 41% higher than that prepared by the easily diffused Cu coating under the same conditions, which will be beneficial to the improvement of the strength of the composites.

Effect of Cu coating thickness on carbon fiber surface on microstructure and mechanical properties of carbon fiber reinforced aluminum matrix composites

Effect of Cu coating thickness on carbon fiber surface on microstructure and mechanical properties of carbon fiber reinforced aluminum matrix composites

Effect of copper coating on interfacial properties, interfacial thermal resistance, microstructure evolution and mechanical properties of aluminum matrix composites

In this study, uncoated and copper-coated short carbon fiber reinforced aluminum matrix composites were prepared by spark plasma sintering. The arrangement of the short carbon fibers was changed by hot rolling. The effect of copper-coating on microstructure evolution and properties was investigated. The results show that the copper-coating can inhibit the formation of harmful product Al 4 C 3 at the interface and protect the structure of short carbon fibers from being damaged during hot rolling. Thus, the hot-rolled copper-coated composites have higher yield strength and better thermal conductivity. The interfacial product and its thickness affect the interfacial thermal resistance. For the interfacial product with low thermal conductivity, the thickness of the product is proportional to the interfacial thermal resistance. The dynamic recrystallization mechanisms of uncoated and copper-coated composites include the continuous dynamic recrystallization mechanism, grain nucleation mechanism of the shear band, and the rotated-Gauss component promoting nucleation mechanism. The copper-coating enhances the interfacial coherence and promotes the nucleation and growth of P-oriented grains and rotated-Gauss-oriented grains by promoting the movement of shear bands. • Copper coating can inhibit the generation of Al 4 C 3 and protect the structure of carbon fiber. • The thickness of amorphous compounds is proportional to the interfacial thermal resistance. • The recrystallization mechanism of coated and uncoated composites was clarified by the evolution of texture. • The enhancement of interfacial coherence by copper coating promotes the growth of recrystallized grains.

Effect of interfacial transition layer with CNTs on fracture toughness and failure mode of carbon fiber reinforced aluminum matrix composites

In this work, a strategy is proposed to construct an interfacial transition layer with CNTs to simultaneously strengthen and toughen composites. Combining CNTs with carbon fiber reinforcements in the aluminum matrix through electrophoretic deposition, and a multiscale hierarchical Cf/Al composite structure is fabricated by pressure infiltration. The mechanical response and failure modes of the composites were investigated. The results indicate that (I) both the strength and weibull modulus of fiber bundles grafting by CNTs were improved and the fiber bundles exhibited the characteristic of progressive failure during the failure process. (II) The tensile strength, fracture toughness and fracture work of the composites grafted with CNTs increased by 128%, 21.6% and 113% respectively, while the ILSS was slightly decreased. The CNTs/Al interfacial transition layer acts as a “fence” to hinder cracks from splitting the fiber bundle structure, and promoting energy dissipation through extensive debonding of the fiber bundle, which also reduces the risk of brittle fracture.

Numerical Simulation on Thermal Stresses and Solidification Microstructure for Making Fiber-Reinforced Aluminum Matrix Composites.

The fabrication of fiber-reinforced metal matrix composites (MMCs) mainly consists of two stages: infiltration and solidification, which have a significant influence on the properties of MMCs. The present study is primarily focused on the simulation of the solidification process and the effect of the active cooling of fibers with and without nickel coating for making the continuous carbon fiber-reinforced aluminum matrix composites. The thermomechanical finite element model was established to investigate the effects of different cooling conditions on the temperature profile and thermal stress distributions based on the simplified physical model. The predicted results of the temperature distribution agree well with the results of the references. Additionally, a three-dimensional cellular automata (CA) finite element (FE) model is used to simulate the microstructure evolution of the solidification process by using ProCAST software. The results show that adding a nickel coating can make the heat flux smaller in the melt, which is favorable for preventing debonding at the coating/fiber and alloy interface and obtaining a finer microstructure. In the presence of the nickel coating, the number of grains increases significantly, and the average grain size decreases, which can improve the properties of the resultant composite materials. Meanwhile, the predicting results also show that the interfaces of fiber–coating, fiber–melt, and coating–melt experience higher temperature gradients and thermal stresses. These results will lead to the phenomenon of stress concentration and interface failure. Thus, it was demonstrated that these simulation methods could be helpful for studying the solidification of fiber-reinforced MMCs and reducing the number of trial-and-error experiments.

The effect of nickel coating on the mechanical properties and failure modes of continuous carbon fiber reinforced aluminum matrix composites

The severe deterioration of the interface is a crucial factor to restrict the performance improvement of composites. In order to understand the effect of interfacial structure on the mechanical properties and failure modes of the composites, the carbon fiber reinforced aluminum matrix (Cf/Al) composites were fabricated by pressure infiltration process at different fabrication temperatures and Ni coating modification. The micro-indentation test is used to determine the mechanical properties of the matrix between fiber bundles to infer the content of the Al4C3. The results indicate that compared with Al alloy, the hardness and modulus of the matrix between the carbon fiber bundles can be significantly increased by 38.5% and 36.5%, while the matrix between Ni-coated fiber bundles remains unchanged. This is due to the Ni coating preventing the carbon fiber against reaction with liquid aluminum during processing the composite, which reduces the generation of brittle carbides. In addition, it was revealed for the first time that the oblique/axial brittle fracture modes of the fibers occurred simultaneously due to severe interfacial reaction, and the brittle failure mechanism was clarified. The presence of Ni coating on the carbon fiber significantly improves the bending strength and interlaminar shear strength (ILSS) of the composite by approximately 81% and 86%, respectively. The Ni coating optimizes the interfacial bonding, so that the interface can absorb more fracture energy under loads. This work can provide a pratical route to prepare and applicate the high-quality continuous fiber reinforced Al matrix composites.

Forming Process and Simulation Analysis of Helical Carbon Fiber Reinforced Aluminum Matrix Composite

In order to promote the industrialization of the large deformation technology of carbon fiber composites, this paper studies a new method of forming of helical carbon fiber reinforced aluminum matrix composite. The purpose is to solve the problem of large deformation of carbon fiber with low elongation and metal matrix with high elongation. By introducing carbon fiber with helical space structure into the aluminum matrix, the helical carbon fiber reinforced aluminum matrix composites were prepared and the subsequent drawing deformation was carried out. Here we systematically studied the large plastic deformation behavior of helical carbon fiber reinforced aluminum matrix composite via a combination of numerical simulations and experiments, and analyzed the deformation law and stress of helical carbon fiber in the deformation process. We found that the plastic deformation of the composite causes local stress concentration around the helical carbon fiber, and the helical carbon fiber will move synchronously with the aluminum matrix during the deformation, and receive the pressure from the aluminum matrix. Second, the best process parameters obtained from the simulation, that is, the drawing die angle α = 7°, when five-pass drawing experiments were carried out, the total deformation reached 58%, and the average elongation of a single pass was 18.9%. The experimental show carbon fiber reinforced aluminum matrix composite with helical space structure can achieve large deformation and high strength. The experimental and simulation are in general agreement, which verifies the correctness of the carbon fiber helical structure model.

Effect of reinforcement volume fraction and T6 heat treatment on microstructure, thermal and mechanical properties of mesophase pitch-based carbon fiber reinforced aluminum matrix composites

To meet the requirements of structural and functional integration, machinability and workability of engineering materials, continuous mesophase pitch-based carbon fiber (MPCF) reinforced 2024 aluminum (Al) matrix composites with 20–50 vol % MPCF were fabricated by vacuum hot pressing method. The effects of MPCF volume fraction and T6 heat treatment on microstructure, thermal and mechanical properties of MPCF/2024Al composites were investigated. The results show that the interface of the as-sintered composite was well bonded. After T6 heat treatment, the amorphous layer at the interface changed from continuous to discontinuous and the interfacial bonding was further improved, but there was no interfacial reaction. The increase of MPCF volume fraction was beneficial to improve the thermal conductivity (TC) and elastic modulus (E) of the as-sintered composites, up to 258.3 W/(m⋅K) and 343.5 GPa respectively, while the composites with 30 vol % and 40 vol % MPCF respectively had the highest ultimate tensile strength (UTS) and a coefficient of thermal expansion (CTE) close to zero. After heat treatment, the TC and E were slightly changed, while the CTE was further reduced and UTS was significantly improved. In this work, the heat-treated composite with 30 vol % MPCF had the highest UTS of 499.3 MPa and good thermal properties, and the TC of this composite may be further improved by using MPCFs with higher TC. Therefore, this composite is expected to become a promising engineering material integrating structure and function.

Mechanical behavior of shape memory alloy fiber reinforced aluminum matrix composites

This study aims to investigate mechanical behavior of NiTi shape memory alloy (SMA) long-fiber reinforced aluminum (Al) matrix composites, experimentally and numerically. The composites with three different pre-memorized shapes of SMA fibers, which were straight-, wave- and rectangle-shaped fibers, were fabricated by powder metallurgical techniques. Three-point bending and tensile test results demonstrated that wave-shape SMA/Al composites showed the highest elastic modulus and strength, and wave-shape and rectangle-shape SMA/Al composites showed high Poisson’s ratio (lateral to longitudinal strain ratio in elastic-plastic regime). The experimental results were examined based on finite element analysis (FEA). It was concluded that internal stresses in the composites, which were introduced during the fabrication processes, highly affected their subsequent mechanical behavior of the composites.

Microstructure and Damping Behavior of Continuous W-Core-SiC Fiber-Reinforced Aluminum Matrix Composites

Microstructure and Damping Behavior of Continuous W-Core-SiC Fiber-Reinforced Aluminum Matrix Composites

Microstructure and mechanical properties of CF/Al composites fabricated by hot coining technique

Carbon fiber reinforced aluminium matrix composites (CF/Al) are recently used in lightweight applications. In this study, two groups of composites are fabricated from 0,5,10, 15 &20 wt% CF. One of them is prepared from 12 wt% nano copper (Cu) coated CF and the other is from the uncoated ones. Composites are manufactured by a hot coining technique through mixing the Al powders with CF using ball milling at 250 rpm, following by hot compaction under 700 MPa at 500°C. The effect of reinforcement weight fraction and surface modification on the microstructure and mechanical properties of CF/Al are investigated. SEM images revealed that the Cu-coated CF samples have lower porosity and higher homogenization than the other non-coated ones. XRD pattern indicates the absence of the undesirable Al4C3 phase in two groups of samples. The microhardness and wear properties of the uncoated CF/Al are significantly improved up to 10 wt % CF. While the ultimate compressive strength value decreased from 320.8 MPa for the pure Al sample to 179.8 MPa for 20 wt % uncoated CF. Cu-coated CF/Al composites showed a higher improvement in the mechanical properties compared with the uncoated composites. The highest reduction percentage between uncoated and coated composites in the wear rate test was about 68.5%. While, the highest increasing percentage recorded in microhardness and compression test were 31.6% and 23.44%, respectively. The results indicated that surface modification of CF could improve the microstructure and mechanical properties of CF/Al composites.

Process optimization, microstructure characterization and thermal properties of mesophase pitch-based carbon fiber reinforced aluminum matrix composites fabricated by vacuum hot pressing

Continuous mesophase pitch-based carbon fiber (MPCF) reinforced aluminum (Al) matrix composites were fabricated by vacuum hot pressing to meet the requirements of good thermal conductivity (TC), low coefficient of thermal expansion (CTE) and resistance to deformation for thermal management materials. The effect of process parameters on the microstructures and TC of 40 vol % MPCF/Al composites and the influence of MPCF volume fraction on the thermal-mechanical properties of MPCF/Al composites were studied. The results reveal that the composites with 20–50 vol % MPCF fabricated at 650 °C/45 MPa/60 min have longitudinal TC of 230.3–288.3 W/(m⋅K), over 90% of the predictions by rule of mixture, longitudinal CTE of 2.28−-0.22 ppm/K and elastic modulus of 147.5–324 GPa. The interface is mainly composed of an amorphous interface layer of 2–5 nm and a very small amount of carbide crystals. Furthermore, these composites have moderate TC, lower CTE and higher specific modulus compared with other Al matrix composites and Al alloys, which indicates they are expected to become unidirectional thermal management materials with integrated structure and function.

Improved wettability and mechanical properties of metal coated carbon fiber-reinforced aluminum matrix composites by squeeze melt infiltration technique

In order to improve the wettability and bonding performance of the interface between carbon fiber and aluminum matrix, nickel- and copper-coated carbon fiber-reinforced aluminum matrix composites were fabricated by the squeeze melt infiltration technique. The interface wettability, microstructure and mechanical properties of the composites were compared and investigated. Compared with the uncoated fiber-reinforced aluminum matrix composite, the microstructure analysis indicated that the coatings significantly improved the wettability and effectively inhibited the interface reaction between carbon fiber and aluminum matrix during the process. Under the same processing condition, aluminum melt was easy to infiltrate into the copper-coated fiber bundles. Furthermore, the inhibited interface reaction was more conducive to maintain the original strength of fiber and improve the fiber–matrix interface bonding performance. The mechanical properties were evaluated by uniaxial tensile test. The yield strength, ultimate tensile strength and elastic modulus of the copper-coated carbon fiber-reinforced aluminum matrix composite were about 124 MPa, 140 MPa and 82 GPa, respectively. In the case of nickel-coated carbon fiber-reinforced aluminum matrix composite, the yield strength, ultimate tensile strength and elastic modulus were about 60 MPa, 70 MPa and 79 GPa, respectively. The excellent mechanical properties for copper-coated fiber-reinforced composites are attributed to better compactness of the matrix and better fiber–matrix interface bonding, which favor the load transfer ability from aluminam matrix to carbon fiber under the loading state, giving full play to the bearing role of carbon fiber.

Modelling and assessment of carbon fiber reinforced aluminum matrix composites and their laminate squeeze casting fabrication

The equibiaxial bend behavior of laminate carbon fiber fabric reinforced aluminum matrix composites is modelled and assessed. Analytical modelling and finite element analysis are comparatively investigated to study the mechanical properties, with particular focus on the elastic modulus and flexural strength. The investigation allows evaluating how far the experimental results deviate from idealized assumptions of the models, which provides insight into the composite quality and the effectiveness of the used laminate squeeze casting technique. Specifically, discrepancies shed light on the interlaminate and fiber-matrix interface bond as well as on the stability of the laminate layers during fabrication. The two model approaches are in good agreement with differences below 8%. Moreover, the models agree with experimental data in predicting an overall improvement in properties with increasing carbon fiber content up to 4.89 vol%. Overall, the composite samples outperform the model predictions, which indicates good interface bonding. However, microstructure investigations also indicate that the outperformance is partly caused by a shifting of the carbon fibers during squeeze casting closer to the later bend tensile loaded surface due to their lower density compared to aluminum. The result is higher load bearing capacity of the composites than estimated by the models that assume perfectly symmetrical composite structure. The experimental outperformance in ultimate flexural strength vanishes at higher carbon fiber contents. This is due to imperfect interlaminate and fiber-matrix interfaces where some defects such as pores, carbides and oxide particles tend to locate, leading to damage initiation and potentially interface failure.