Ni-coated Carbon Fiber Research Articles

Strong composite SnAgCu solder joints with internal aligned carbon fibers by magnetic field

Lightweight carbon fibers with high mechanical performance are referred to as an ideal reinforcement for an extensive variety of composite materials. However, the addition of carbon fibers into electronic interconnection solders is extremely limited so that the expected reinforcement in the mechanical properties of the composite solder joints has not been completely realized. Here, we used magnetic fields to align Ni-coated carbon fibers in the Sn-3.0Ag-0.5Cu solder vertically with the Cu substrate and prepared the oriented composite solder joints. We achieved a further improvement in the shear performance of composite solder joints (∼58 MPa) with a small addition of Ni-coated carbon fibers (0.5 wt%), which is 25% higher than that of pristine joints. It is found that these vertically oriented carbon fibers changed the propagation path of shear cracks and thus increased the shear resistance. Ni-coated carbon fibers also promoted nucleation of interfacial Cu6Sn5 in the solder joints during reflow, but prevented the formation of brittle Cu3Sn phase during isothermal aging, thus ensuring the high shear strength of composite solder joints after isothermal aging. This success provides a new pathway to fabricate a strong composite solder joint with a limited addition of reinforcements by aligning their orientation.

Internal structural evolution of conductive cementitious composites subjected to multi-step ohmic heating curing strategy under severely cold temperature

Ohmic heating (OH) curing is a novel method for winter concrete construction, a more effective strategy is required for the modification of this method to achieve the high-quality and rapid structure fabrication. In this work, a multi-step OH curing strategy was introduced to prepare Ni coated carbon fibers and nano carbon fibers reinforced conductive cementitious composites (NiCFs/NCFs-CCC) under −20 °C, detailed thermal strain evolution, mechanical strengths and microstructure of the samples were clarified. With the increasing OH curing step, NiCFs/NCFs-CCC exhibited lower thermal strain during the curing process. The thermal strains inside 1-step OH cured sample was larger than 4000 με, which was much larger than those of 2-step OH cured sample and 3-step OH cured sample (lower than 2500 με), highlighting the advantage of multi-step OH curing on reducing the potential internal damage. Moreover, 3-step OH cured sample exhibited higher compressive strength of 68.2 MPa, meeting an increase of 23.1% with that of 1-step OH cured sample. MIP analysis result showed the similar regularity that multi-step OH curing was beneficial for the densification of the pore structure with lower porosity and higher proportion of harmless pores. This work provides a new insight on the modification of OH curing method, which has been verified by the internal structural evolution of the samples, providing an effective curing strategy for high-quality winter concrete construction.

Effect of Cu/Ni coating on the interface and mechanical properties of Cf/2024Al composites

To improve the interface between the carbon fiber and aluminum matrix, the carbon fibers were modified with Cu coating and Ni coating by using electroless plating. The Cu-coated and Ni-coated carbon fibers reinforced 2024Al matrix composites (denoted as Cf(Cu)/2024Al and Cf(Ni)/2024Al) were prepared by spark plasm sintering at 480 °C for 10 min under a uniaxial pressure of 30 MPa. Microstructure observations show that the interfacial reaction between carbon fibers and aluminum matrix can be efficiently obstructed by coating the carbon fiber with Ni, while it still proceeds as the carbon fibers were coated with Cu. The nanohardness of the interface for Cf(Cu)/2024Al composite is 2.68 GPa, which is 16.5% higher compared to Cf(Ni)/2024Al composite (2.30 GPa) due to the produced hard Al4C3 at the interface. The tensile strength and strain of Cf(Ni)/2024Al composites are 284 MPa and 6.4%, which are increased by 4.4% and 28.0% respectively compared to Cf(Cu)/2024Al composites. The Ni coating plated on the carbon fiber results in moderate interfacial bonding and avoids damage to the carbon fiber, which is efficient in deflecting cracks and increasing the crack propagation path, as well as consuming more fracture energy.

Wear behavior of Ni-coated carbon fiber and ZrC particles reinforced 2024Al matrix composites

The dry sliding wear behavior of ZrC particles and carbon fiber reinforced 2024Al matrix composite rubbed against AISI52100 bearing steel was investigated at different loads and sliding velocities. The wear rate of the composite increased with increasing load, while an opposite trend was recorded as the velocity increased. With increasing load and speed, the wear mechanism changed from major abrasion wear, slight adhesive wear, and oxidative wear to dominant oxidative wear, secondary abrasion, and adhesive wear. The improved wear resistance of the composite over that of the 2024Al alloy is attributed to the steady mechanically mixed layer supported by the harder and stronger composites, as well as the self-lubricating carbon fibers.

Electrical transport behaviors of Ni layer on carbon fiber

Recently, carbon materials have been employed for the core of metal wires, contributing to their weight reduction. Low weight is a required characteristic for cables used in air, water, and ground transportations, in order to maximize fuel efficiency. Nowadays, the hybridization of C with metal for the creation of C-based metal wires is achieved through different approaches. A thin metal layer of Ni is usually applied through electroless plating on the surface of C fibers (CFs; diameter = 7 μm). Transport studies conducted on a single strand of Ni-coated CFs (Ni-CF) have indicated that, depending on the grain size, phonon-supported hopping or phonon-driven electron scattering transport can dominate. At a given P concentration (∼11 at.wt.%) and when the average grain size is < 100 nm, phonon-driven electron scattering transport dominates: as the temperature increases, the resistance increases as well, resulting in a positive temperature coefficient of resistance (TCR) (∼1.5 × 10 −3 /K at 300 K). This is a conduction behavior typically observed in metals. However, when the average grain size is > 100 nm, impurity-related variable range hopping (VRH) transport dominated, leading to a negative TCR (∼1.0 × 10 −4 /K at 300 K); in this case, the resistance decreases with increasing temperature, as in a semiconductor. Our results imply that, by controlling the plating condition and surface morphology of CF, it is possible to modulate metal properties (i.e., the metal-insulator transition (MIT)). • A Ni layer was deposited on the outside of carbon fibers (CFs) by electroless electrochemistry. • The temperature-dependent resistance of the Ni-CFs was measured in a closed-cycle refrigerator (CCR). • Transport studies conducted on a single strand of Ni-coated CFs have indicated that, depending on the grain size, phonon-supported hopping or phonon-driven electron scattering transport can dominate.

Magnetic properties of Ni-coated fibers in a polymer matrix for electro-magnetic interference shielding applications

Electromagnetic interference shielding composite materials can be designed with properties that are tailored for specific applications. We have explored the magnetic properties of Ni-coated carbon fibers embedded in a polymer matrix through an extrusion process. This method can produce large, pliable flat sheets, which can be easily bent and shaped. Microscopy imaging shows that the extrusion process preferentially orders most of the fibers with their long axis along the extrusion direction. The measured samples reached 90% of the saturation magnetization value at a field of approximately 800 Oe along the extrusion direction, much lower than needed for other directions (in-plane perpendicular to the extrusion or perpendicular to the foil surface). A field on the order of 6 kOe must be applied to obtain the full saturation of the magnetization in all three directions. The absorption characteristics were measured, with zero external applied field to determine the shielding effectiveness of the composite materials for multiple orientations with respect to the TE10 mode of an S-band waveguide. The nickel-coated carbon fiber composite materials exhibit dramatic orientation-dependent shielding effectiveness. The most effective orientation has shielding effectiveness of up to 45 dB at 4.5 GHz, which is comparable to multi-walled carbon nanotube composites with similar volumetric filling fractions.

Ferromagnetic resonance of hollow micron-sized magnetic cylinders

We have explored dynamic magnetic properties of micron-sized Ni-coated carbon fibers embedded in a polymer matrix for electromagnetic interference shielding applications. These hollow magnetic cylinders exhibit unusual dynamic magnetic properties, which were measured with a broad-band ferromagnetic resonance system (FMR). We observe three families of FMR modes, which are connected to different physical locations within the cylinder. We develop a simple analytic model to explain these results and corroborate resonant mode profiles with micromagnetic simulations. We find excellent agreement between experimental results and theoretical models. Our work indicates that global demagnetizing factors are not appropriate for understanding the spin motions in these hollow cylinders. The FMR absorption observed in these hallow cylinders is very different from those observed in nanowires or solid cylinders. The field-swept envelope of all the observed FMR resonances is very broad, approximately μ0H = 1 T, with a linewidth of individual modes around μ0ΔH = 250 mT. This can be important for electromagnetic shielding applications.

The aging behavior of Ni-coated carbon fibers and ZrC particles reinforced 2024Al matrix composites

In this paper, the aging behavior of Cf(Ni)-ZrC/2024Al composites with a quasi-network structure was studied carefully. The microstructure observation exhibits that the ZrC particles, carbon fibers, and Al matrix form a good interface bonding. The interfacial phase between the carbon fiber and Al matrix exhibits good thermostability during solution and aging treatment. With the addition of carbon fibers and ZrC particles, the composites only take 8 h to reach peak-aged condition while in monolithic 2024Al alloy, it needs 12 h. The peak-aged hardness of the composites is 136.4 HV, having 15.2% increments than 2024Al (118.4 HV). The yield, tensile strength, and strain of the peak-aged composites are 350.5 MPa, 536.4 MPa, and 14.8% respectively, which are improved by 56.5%, 45.8%, and 52.6% compared with 2024Al. The yield and tensile strength of composites are increased with time going by until they reach a peak aging state, agreeing well with that of hardness. The TEM observations of precipitated phases demonstrate the size and number of Al 2 Cu and Al 2 CuMg present a similar variation tendency. The improved tensile property of the composites is mainly due to pulled-out carbon fibers, quasi-network structure, outstanding interface bond, and precipitate strengthening. • The Cf(Ni)-ZrC/2024Al composites only take 8 h to reach to peak-aged condition, while the 2024Al needs 12 h. • The yield, tensile strength and strain of the composites are significantly improved compared with the 2024Al. • The improved strength is due to pulled-out carbon fiber, quasi-network structure, good interface bond and fine precipitate.

Impact of Ni-coated carbon fiber on the interfacial (Cu,Ni)6Sn5 growth of Sn-3.5Ag composite solder on Cu substrate during reflow and isothermal aging

In this work, a novel composite solder was fabricated by mechanically incorporating Ni-coated carbon fiber (Ni-CF) into the Sn-3.5Ag solder paste in an effort to improve the overall service capability, where the intermetallic compound (IMC) formation and growth is a fundamental issue for consideration. General findings indicated that the addition of Ni-CF did not significantly impact the processing properties of the base alloy, such as melting temperature and wettability, when the reinforcement fraction was less than 2 wt%. Isothermal aging tests were carried out to study the formation and growth of interfacial IMC layers between the composite solder and Cu substrate. The addition of Ni-CF into Sn-3.5Ag solder could effectively promote the formation of interfacial (Cu, Ni)6Sn5 phase during reflow but retard its growth in the solid-state aging. The addition of 1 wt% Ni-CF was believed to be more effective to restrict and reduce the subsequent growth rate of the IMCs during solid-state aging due to the initial formation of a thicker (Cu, Ni)6Sn5 layer after reflow.

The Mechanical properties and tribological behavior of Ni coated carbon fibers reinforced with Al 7075 metal matrix composites

The carbon fibers (CF’s) are preferred material whose usage has been very widely growing in various industries that are synthesizing novel composites because it exhibits superior properties. Researchers worldwide are focussed on improving the mechanical performance of the composites reinforced with carbon fibers. In the present work nickel coated carbon fibers were reinforced with Al7075 via stir casting metallurgy followed tensile, hardness and wear studies. The specimens with 0%, 1%, 2%, 3% CF’s reinforced composites were fabricated and subjected to tests as per the ASTM standards, the tension test showed that the tensile strength was increased by 26% the composite hardness was high as 79 BHN as compared with ascast alloy. The Tribological studies were carried out, the sliding wear test results revealed that the wear rate was increased with the increase in the sliding distance.

Broadband and tunable high-performance microwave absorption properties by Ni-coated carbon fibers

Composites of carbon fibers (CFs) and magnetic metals have concerned attention for tunable microwave absorption materials (MAMs). In this work, magnetic nickel (Ni) particles were coated on the CFs surface by an electroplating technique. Different morphology of Ni-coated CFs was established by setting the plating time. The microstructure, electric and magnetic properties, complex permittivity and permeability, and reflection loss (RL) of the Ni-coated CFs were specified as a function of the surface morphology of composites. SEM and EDX results displayed that Ni particles are uniformly deposited on the surface of CFs. Moreover, the Ni-coated CFs with different coating morphologies exhibit different microstructure. The creation of a magnetic Ni layer onto CFs improved composite properties, not only raising the saturation magnetization (17–46 emu/g) but also enhancing electrical conductivity (361–594 S/cm). The electromagnetic parameters and RL values of the Ni-coated CFs were investigated over the 2.0–18.0 GHz frequencies. The minimum RL could reach up to −64.8 dB at 14.9 GHz with 2.0 mm matching thickness and high effective bandwidth of 2.2–18.0 GHz. It has been displayed that the properties of Ni-coated CFs can be effectively controlled by changing the morphology of the Ni layer, which provides a novel route to fabricate Ni-coated CFs with tunable and broadband microwave absorption properties.

Interficial Bonding within Cu-based Composites Reinforced with TiC- or Ni-coated Carbon Fiber

Interficial Bonding within Cu-based Composites Reinforced with TiC- or Ni-coated Carbon Fiber

Improved strength, toughness and electrical properties of rigid polyurethane composites reinforced with Ni-coated carbon fibers

Improved strength, toughness and electrical properties of rigid polyurethane composites reinforced with Ni-coated carbon fibers

Stabilized Interfacial Intermetallic Compound Evolution in Ni-Coated Carbon Fiber Reinforced Sn-3.5Ag Composite Solder Joint

Stabilized Interfacial Intermetallic Compound Evolution in Ni-Coated Carbon Fiber Reinforced Sn-3.5Ag Composite Solder Joint

Enhanced Surface Energetics of CNT-Grafted Carbon Fibers for Superior Electrical and Mechanical Properties in CFRPs.

Surface enhancement of components is vital for achieving superior properties in a composite system. In this study, carbon nanotubes (CNTs) were grown on carbon fiber (CF) substrates to improve the surface area and, in turn, increase the adhesion between epoxy-resin and CFs. Nickel (Ni) was used as the catalyst in CNT growth, and was coated on CF sheets via the electroplating method. Surface energetics of CNT-grown CFs and their work of adhesion with epoxy resin were measured. SEM and TEM were used to analyze the morphology of the samples. After the optimization of surface energetics by catalyst weight ratio (15 wt.% Ni), CF-reinforced plastic (CFRP) samples were prepared using the hand lay-up method. To validate the effect of chemical vapor deposition (CVD)-grown CNTs on CFRP properties, samples were also prepared where CNT powder was added to epoxy prior to reinforcement with Ni-coated CFs. CFRP specimens were tested to determine their electrical resistivity, flexural strength, and ductility index. The electrical resistivity of CNT-grown CFRP was found to be about 9 and 2.3 times lower than those of as-received CFRP and CNT-added Ni-CFRP, respectively. Flexural strength of CNT-grown Ni-CFRP was enhanced by 52.9% of that of as-received CFRP. Interestingly, the ductility index in CNT-grown Ni-CFRP was 40% lower than that of CNT-added Ni-CFRP. This was attributed to the tip-growth formation of CNTs and the breakage of Ni coating.

Production and mechanical characterization of Ni-coated carbon fibers reinforced Al-6063 alloy matrix composites

In this study, it aimed to produce carbon fiber (CF) reinforced aluminum metal matrix composite by squeeze casting method. In order to overcome the wetting problem between the aluminum matrix and the reinforcing agent, carbon fibers were coated with Ni coating with electroless technique. Different bath pH values and hypophosphite (HP), coating durations and bath temperature were investigated. SEM, EDS and XRD methods used to determine the characterize the layers. It has been observed that increasing the pH of the bath, coating time, bath temperature and amount of hypophosphite increases the thickness of the Ni coatings on the carbon fibers. Two different thicknesses of coatings were used with different volume fractions of fiber used to reinforce the 6063 aluminum as matrix alloy. Squeeze casting process was used for the production of the composites to increase the connection between the matrix and the carbon fibers. After achieving a good bonding, three-point bending, Charpy impact, and Vickers hardness tests were carried out to investigate the difference of at the mechanical properties. It was observed from the mechanical tests that while the hardness and the three-point bending strength was increasing the impact strength was decreasing after the carbon fiber addition. Also coating, in general, helping the mechanical properties, mechanical properties of composites are badly affected by higher coating thicknesses.

Eliminating lightning strike damage to carbon fiber composite structures in Zone 2 of aircraft by Ni-coated carbon fiber nonwoven veils

By using standardized Waveforms C and D, this study explored the lightning strike protection (LSP) effectiveness of nickel coated carbon fiber nonwoven veils (Ni-CFNVs) on protecting the carbon fiber composite structures in Zone 2 (aircraft lightning zoning). The post-lightning damage was evaluated by visual inspection, ultrasonic scan and residual strength test. Results showed that the Ni-CFNV of 70 g/m2 eliminated lightning strike damage inflicted by both waveforms and it even performed better than the commercial expanded copper foil of 73 g/m2. Therefore, the Ni-CFNV will be a promising alternative to metal mesh for eliminating lightning strike damage to the structures in Zone 2. The remarkable LSP effectiveness of Ni-CFNV can be explained by its integration of high electrical conductivity of Ni-coating and prominent ablation resistance of carbon fiber. The experiments indicate that not only the electrical conductivity, but also the ablation resistance of LSP layer greatly influences the LSP effectiveness.

Microstructure and antioxidation performance of SiC-ZrO-MoSi2/Ni coated carbon fiber produced by composite electroplating

To improve the oxidation resistance ability of carbon fiber (CF) in the high temperature environment, the composite electroplating method had been used to fabricate SiC-ZrO-MoSi2/Ni coating at the surface of CF. Both nanoparticles and Ni-matrix were plated onto CF successfully while the mechanical property of coated CF was only slightly weakened. The oxidation resistance performance of CF and the CF reinforced phenolic resin composites had been improved obviously. The microstructure of coatings was investigated by scanning electron microscope and X-ray diffraction analysis. Thermal gravimetric analysis was applied to test the anti-oxidation ability of coated CF. The mechanism of oxidation process had been discussed. It can be concluded that composite plating is an effective way to make composite coatings which can enhance the anti-oxidation ability of CF.

Interface Characteristics and Damping Performance of Ni-coated Short Carbon Fiber Reinforced AZ91D Magnesium Matrix Composites

Interface Characteristics and Damping Performance of Ni-coated Short Carbon Fiber Reinforced AZ91D Magnesium Matrix Composites

Ni-Coated Carbon Fiber as an Alternative Cathode Electrode Material to Improve Cost Efficiency of Microbial Fuel Cells

Electrode material is a key component in microbial fuel cells (MFCs), and exploring cost-effective electrode materials will greatly help with MFC development, especially the scaling up. In this study, a commercially available material – nickel-coated carbon fiber (Ni-CF) has been investigated as an alternative cathode electrode material to carbon cloth (CC). Both three-electrode cell and MFC tests are carried to examine electrochemical performance and actual electricity generation of the prepared cathode electrodes. It is found that Ni-CF exhibited higher current generation in linear sweep voltammetry (LSV) and lower resistance in electrochemical impedance spectroscopy (EIS) tests than those of CC and CF. When being coated with AC, Ni-CF has the highest actual loading amount among the tested materials. As a result, AC/Ni-CF leads to lower charge transfer resistance (95.1Ω) and higher current density (8.07mAm−2) than AC/CC (115.3Ω and 3.40mAm−2). In the MFC test, the cathode using AC/Ni-CF results in the maximum power density of 6.50Wm−3, higher than AC/CC at 4.29Wm−3. This high power output gives cost efficiency of AC/Ni-CF at 299.0mW $−1, nearly twice that of AC/CC (151.7mW $−1). The initial AC coating amount of 4g is found to be the optimal amount to achieve optimally actual AC loading amount on the cathode electrode with balanced catalytic ability and (possible) oxygen transfer. Those results encourage further investigation of Ni-CF for MFC applications towards improved performance and cost efficiency.