Reinforced Al Composites Research Articles

Microstructure, interfacial reaction behavior, and mechanical properties of Ti3AlC2 reinforced Al6061 composites

The interfacial reaction behavior of Al and Ti3AlC2 at different pouring temperatures and its effect on the microstructure and mechanical properties of the composites were investigated. The results show that the addition of 3.0 wt.% Ti3AlC2 refines the average grain size of α(Al) in the composite by 50.1% compared to Al6061 alloy. Morphological analyses indicate that an in-situ Al3Ti transition layer of ~180 nm in thickness is generated around the edge of Ti3AlC2 at 720 °C, forming a well-bonded Al−Al3Ti interface. At this processing temperature, the ultimate tensile strength of Al6061−3.0 wt.%Ti3AlC2 composite is 199.2 MPa, an improvement of 41.5% over the Al6061 matrix. Mechanism analyses further elucidate that 720 °C is favourable for forming the nano-sized transition layer at the Ti3AlC2 edges. And, the thermal mismatch strengthening plays a dominant role in this state, with a strengthening contribution of about 74.8%.

Preparation, microstructure and interfacial architecture of Ni-coated Ti3C2Tx reinforced Al6061 composites

Aluminum matrix composites (AMCs) reinforced by Ti3C2Tx are receiving increasing attention. However, the key constraints to its application breadth are the poor thermal stability and its poor interfacial bonding with aluminum (Al). In this paper, the surface modification of Ti3C2Tx is carried out by chemical Ni coating, and the effects of such reinforcement on the microstructure and interfacial architecture, as well as the mechanical properties of the Al6061 composites before and after Ni-coated are compared. The results show that Ni-coated Ti3C2Tx improves its dispersion in the Al melts and blocks the interfacial reaction between Al and Ti3C2Tx. HRTEM analysis shows that the dense Ni nanoparticles on the surface of Ti3C2Tx optimize its interfacial structure with Al. The mismatch of (102)Al3Ni//(1−11)Al is 4.3 %, indicating that the Al6061–2.5 wt% Ti3C2Tx@Ni (AT2.5@Ni) composites are strengthened by the form of Al3Ni-Al interfacial coherence. The yield strength, tensile strength, and elongation of AT2.5@Ni composites are 122.1 MPa, 223.4 MPa, and 5.2 %, which are 53.0 %, 57.9 %, and 2.0 % higher than that of Al6061 matrix, respectively. The better mechanical properties are mainly attributed to the strong Ti3C2Tx-Ni-Al3Ni-Al interfacial architecture formed in the composites, resulting in the effective load transfer from matrix to Ti3C2Tx.

Hot deformation behavior of recycled-Be/2024Al composites prepared by pressure infiltration method

It is necessary to confirm the appropriate processing parameters for recycled-Be/2024Al composites before hot processing. Therefore, hot compression experiments were conducted on 40 and 50 vol% recycled-Be/2024Al composites prepared by pressure infiltration method. Meanwhile, the constitutive equations were established. The activation energy increased with the volume fraction of reinforcement, which means the increasing difficulty for composites to deform. However, different from ceramic reinforcements, Be is able to deform with matrix coordinately. This characteristic makes recycled-Be/2024Al composites more prone to deformation than ceramic reinforced Al composites with the same volume fraction of reinforcements. The processing maps of 40 and 50 vol% recycled-Be/2024Al composites have been drawn, and the appropriate processing parameters for 40 and 50 vol% recycled-Be/2024Al composites were determined as 495–525 °C,0.0006–0.0016 s−1 and 500–530 °C,0.016–0.04 s−1, respectively. The microstructures of samples hot compressed with various parameters were observed to identify the accuracy of processing maps.

Nano reinforced aluminium based Metal Matrix Hybrid Composites - an overview

Aluminium and its alloys find their application in aerospace, automobile, and marine sectors as it costs less and properties like low density, good ductility, high resistance to corrosion etc. However, aluminium has many drawbacks like low resistance to abrasion and wear, poor strength etc. These drawbacks can be overcome by adding certain materials as reinforcement into pure aluminium and its alloy. Hybrid reinforcement imbibes superior properties to Al matrix composites, compared along with single reinforced Al composites. The properties of Al matrix composite is enhanced by reinforcing with nano particles compared to micro reinforcement. In recent years, research advancement is focusing on fabrication of composites prepared by nano reinforcement materials. Various nano materials are used to fabricate aluminium/alloy matrix composites for improved abrasion, enhanced wear properties, high specific strength, better corrosion resistance etc. This review paper gives an overview of various processing techniques, different nano reinforcements used for fabrication of aluminium and its alloy matrix. Further, Hybrid Nano composite properties along with their types, concentration of reinforcement and microstructure of the composite fabricated are discussed. Finally, Future trends and potential applications of aluminium based nano composites are presented and have been concluded with recent advancements in the specified area.

The formation mechanisms and mechanical effects of lattice defects in carbon nanotube reinforced 2024Al composite

Lattice defects significantly affect the mechanical performance of metallic materials. In this study, lattice defects of a carbon nanotube reinforced 2024 aluminum alloy (CNT/2024Al) composite were systematically investigated and the contribution of carbon nanotubes was illustrated. The results showed that dislocations and grain boundaries were closely related to the deformation behavior and lead to discontinuous yielding phenomena. Moreover, the carbon nanotubes reduced the stacking fault energy, which was conducive to forming stacking faults and a small number of twins in the composite. The stacking faults, twin boundaries, and intragranular Al4C3 phases hindered dislocation motion, thus enhancing the mechanical properties of the composite. In addition, the novel formation mechanism of the 9R structure was revealed: the Σ3(11‾1)/(151) incoherent twin boundary may dissociate into two tilt walls bounding a 9R structure (zone axis: [1‾01]), which enriches understanding of the relationship between Σ3 twin boundaries and the 9R structure.

Modification of FeCoNi1.5CrCuP/2024Al composites subject to improved aging treatments with cryogenic and magnetic field

High-entropy particles reinforced 2024Al composites exhibit the advantages as prominent particulate performance and metal/metal interfacial strengthening, which is the focused topic in the field of advanced composites. In order to adjust the metastable state of solid-solute samples, a variety of aging treatments of FeCoNi1.5CrCu/2024Al composite were processed incorporating oil bath aging (OBA), deep cryogenic and magnetic field treatment (DCT and MFT) in order to adjust the metastable state of solid-solute samples. The results show that in comparison to sole optimized OBA(170 ℃×10 h) both the DCT and MFT accelerate the aging process, that is, the peak aging can be reached at a lower aging temperature(160 ℃×10 h，DCT-OBA) even a shorter aging time(160 ℃×8 h，MFT+OBA). The optimized DCT-OBA and MFT+OBA samples exhibit the similar characteristic as high compactness, high-density dislocations, voluminous nanometer sub-grains, massive GPB areas and plentiful fine precipitates, small-sized and uniformly distributed HEAP and tight-binding interface. The multiple strength and toughness of the composites are attributed to the significant improvement of comprehensive performance. In comparison to the SS one, the least amplification for the three optimized samples are 10.6 %(compactness), 57.1 %(microhardness),10.0 %(yield strength) and 86.1 %(maximum compression ratio).

Characterization on Specific Wear Rate of Al Composite Reinforced with nano-Al2O3 Using Taguchi’s Technique

The aim of the investigation was to study and predict wear properties of nano Al2O3 reinforced Al composite fabricated by a two-step stir casting method. A pin-on-disc wear device was used to study the wear characteristics. An L9 Orthogonal array was selected as per Taguchi's method to analyze the results and ANOVA was used to examine the impact of applied force, sliding speed, and duration on specific wear rates with "smaller the better" as selection criteria. As per the investigation, applied load significantly influences the particular specific wear rate. Sliding duration is the second most important factor, whereas sliding speed is the factor that has the lowest impact on a given specific wear rate. We created a regression equation with R2 and adj R2 of 99.85% and 99.76% respectively that can estimate the specific wear rate of nano Al2O3 reinforced Al composite. An apple-to-apple comparison between experimental and projected values was built using two confirmation tests, and it revealed an inaccuracy of 2.1% and 6.6%, using a scanning electron microscope. The worn-out surface of the samples with the lowest and greatest specific wear rates was examined and identified with unique oxidation layers and cracks.

Mechanical properties of calcium carbonate and silicon carbide reinforced aluminum composite

Metal matrix composites have been researched from a long time and used in various industries such as aerospace, automobile, sports and performance-oriented applications. The reason for usage of Aluminum metal matrix composites is due to their low density and high-performance properties. AMMCs are easy to procure and process, making them an economically viable material. Research on AMMCs has been of great interest due to high margin of improvement and future scope. In this research, CaCO3 reinforced Al composite was fabricated using stir casting process. CaCO3 in the form of egg shell powder, SiC were introduced into Al 6063 alloy. The fabricated specimen was tested for hardness, tensile strength and wear resistance. The effect of reinforcement percentage played a major role in determining the material properties after fabrication. Test results indicated change in material behavior and giving suitable explanation for increased material performance.

Microstructure and mechanical properties of Bp/Al neutron shielding composites

In this paper, a new type of neutron shielding material, boron particles reinforced Al composites (Bp/Al), was prepared by vacuum hot pressing method. Effect of volume fraction of boron particles and heat treatment on the microstructure and mechanical properties of the composites was studied. The results show that boron particles distribute uniformly in the composites and possess a good interface bonding with the matrix. Meanwhile, some boron particles react with Al matrix to form product AlB2 in the interfacial area. The bending strength of the composites first increases and then decreases as the volume fraction of boron particles increasing, and it also increases significantly after T6 treatment. The highest bending strength, 398 MPa, is obtained as the boron content is 30 vol%. Superabundant boron particles result in more micro-pores and micro-cracks through particle agglomeration and interfacial reaction. Therefore, the Bp/Al composites show brittle fracture when bearing excess external load.

Cyclic deformation and dynamically induced short-range ordering in small particles reinforced Al composite

Cyclic deformation of an Al-Cu-Mg composite strengthened by small non-shareable particles was firstly investigated through strain controlled low-cycle fatigue (LCF) tests. In comparison with the reported Al-Cu-Mg composites, the in-situ TiB2/Al-Cu-Mg composite presented higher fatigue life at all the tested strain amplitudes. The composite exhibited cyclic hardening response, which was contributed by non-shareable particles, dislocations and dynamically deformation-induced short-range orderings in the Al matrix. Considering plastic strain evolution, the cyclic hardening model was established and well fitted with experimental results. When cyclic loading was controlled at higher strain amplitudes, the serrated flow occurred on stress-strain hysteresis loops and then it disappeared after the first few cycles related to the occurrence of dynamic strain aging. Onset of the stress serration on stress-strain hysteresis loop was greatly dependent on the strain amplitude rather than cumulative plastic strain. Finally, the correlative cyclic hardening model of small particles reinforced Al composite was analytically discussed based on microstructure evolution and cyclic stress-strain responses.

Mechanical Response of CNT/2024Al Composite to Compression and Tension at Different Strain Rates

Compressive and tensile properties of a carbon nanotube (CNT) reinforced 2024Al composite are investigated under quasi-static and dynamic compression as well as quasi-static tension, along three different directions (extrusion, normal and transverse directions). Upon compression, yield and fracture strengths of the composite show negligible strain rate effect and mechanical anisotropy as manifested in the compressive stress–strain curves. Fractography and profilometry show that fracture surfaces are rough shear fracture planes for quasi-static compression; however, smooth conical fracture surfaces are observed for dynamic compression as a result of more homogeneous damage nucleation and growth, leading to high ductility under high strain rate loading. Pronounced mechanical anisotropy is observed for the composite under quasi-static tensile loading. Ductility or fracture strain is the highest along the normal direction, because debonding along the particle and lamellar interfaces is suppressed along this direction. In situ optical imaging along with digital image correlation is utilized to obtain the deformation dynamics of the composite along the three different directions. Stripe-shaped strain localizations appear in the strain fields along the extruded and tangential directions, while the strain fields are approximately uniformly distributed along the normal direction, consistent with the stress–strain curves.

Effect of GS stacking on the effective elastic modulus of carbon fiber reinforced GS-Al nanocomposites

ABSTRACT This research article aims to estimate the consequence of graphene sheet (GSs) reinforcement in carbon fiber composite on the elastic modulus of the composite. Aluminum (Al) is taken as matrix material. Molecular dynamics (MD) approach is employed to perform the nanoscale modeling of the GS-embedded Al nanocomposite. The resulting elastic modulus of nanocomposite is further utilized to estimate the elastic modulus of nanocomposite at micro-and macro-scale. At higher scales, i.e. micro- and macro-scale, semi-empirical and analytical methods have been utilized to calculate the elastic modulus of the composite. The elastic moduli of carbon fiber–embedded GS–Al nanocomposites are found to be enhanced relative to the pristine carbon fiber–reinforced composites, irrespective of stacked or non-stacked GSs. It is established that stacking of GSs only affects marginally the elastic moduli of carbon fiber–reinforced Al composites.

Microstructure characterization and mechanical properties of in situ synthesized Ti2(Al,Si)C reinforced Al composites

A novel composite with in situ synthesized of Ti 2 (Al,Si)C solid solution reinforced Al matrix was fabricated in Ti 2 AlC-Al-Si material system via one-step solid solution and densification by spark plasma sintering method. The relationship between microstructure, phase composition and mechanical properties of composites doped with different Si content (1, 2 and 3 wt%) and fabricated at different sintering temperature (580, 570 and 560 °C) were investigated. The optimal sintering temperature of composites with increasing the Si addition was carefully determined. The interface reaction was effectively regulated under different Si additions. X-ray photoelectron spectroscopy ( XPS) and nanoindentation test results reveal that Si formed Si C covalent bond in Ti 2 (Al,Si)C solid solution, and with the increase of Si addition, the hardness and elastic modulus of Ti 2 (Al,Si)C increased by 6.75% and 4.23% in the composites prepared by the three optimal processes. The tensile tests show that when the addition of Si was 2 wt% and the sintering temperature was 570 °C, the composites demonstrated an optimal balance of strength and plasticity. The ultimate tensile strength reached 226 MPa with a strain of 14.33%. Moreover, when added to 3 wt% and the sintering temperature decreased to 560 °C, the composite achieved a significant improvement in elongation. The performance are mainly attributed to the strengthening of Ti 2 (Al,Si)C solid solution and the regulation of interface reaction. • In situ synthesized Ti 2 (Al,Si)C solid solution reinforced Al composite is fabricated by spark plasma sintering method. • The reaction phase TiAl 3 is inhibited by the increase of Si addition and decrease of sintering temperature. • With the increase of Si addition, the hardness and elastic modulus of Ti 2 (Al,Si)C increase by 6.75% and 4.23%. • The Al composite with 20 vol% Ti 2 AlC and 3 wt% Si demonstrates a large strain of 16.33%.

Multiscale numerical and experimental analysis of cooling-induced thermal shrinkage behaviors and residual stresses in 2.5D woven fiber/aluminum matrix composites

The cooling-induced thermal shrinkage behavior and residual stress in fabrication of 2.5D woven fiber reinforced Al composites were investigated by numerical and experimental approach. A microscale finite element (FE) model was established to determine the transversely isotropic thermal shrinkage of the Al-impregnated yarns. The validated properties were subsequently input into a mesoscale FE model for the composites, in which the temperature-dependent properties of the constituent materials were incorporated. Parallel experiments were carried out to verify the thermal shrinkage behaviors and the residual stresses that were predicted by the FE simulations. The residual stress distribution of the matrix pocket, warp and weft yarns were studied, and their contributions to the local damage of matrix pocket and interface were analyzed. Based on the verified model, the effect of fabric structure on the residual stresses and macroscopic shrinkage properties were parametrically evaluated. The results make a contribution to evaluating the cooling-induced residual stress, local damage, and shrinkage behavior of metal matrix composites reinforced with complex fabric.

Mechanical and Wear Characterisation of Boron Carbide Particles Reinforced Al2030 Alloy Composites Developed by Two Stage Stir cast Method

ABSTRACT In this study, two-step stir process was used to synthesis aircraft Al2030 alloy reinforced composites with 3 and 6 weight percentages of B4C particles. This innovative two-step stir casting process improves the wettability of Al2030 and B4C particles. SEM and EDS were used to characterize the microstructures of the Al2030 alloy with B4C composites. Different mechanical features of Al2030 alloy composites were investigated to determine the impact of B4C particle addition on hardness, ultimate strength, yield strength, and ductility. In addition, the wear behavior of the produced Al2030 alloy with B4C composites was investigated utilizing a pin-on-disc apparatus with variable normal load and sliding velocity over a constant 2000 m sliding distance. SEM micrographs demonstrated homogeneous particle distribution, while EDS patterns validated the elements in the B4C reinforced Al composites. The addition of B4C particles increased mechanical characteristics; further improvement was obtained by increasing the weight fraction of B4C particles in the Al2030 matrix alloy. On the other hand, reduced ductility of the composites was observed due to the incorporation of B4C particles in the soft Al matrix. To determine the effect of B4C particles on tensile failure, wear surface of the composites, fractography and worn surface analyses were performed.

Microstructure and mechanical behaviors of Ti3AlC2 triggered in-situ Al3Ti and TiC reinforced 2024Al composite

In this work, 2024Al matrix composite reinforced by in-situ Al3Ti and TiC was fabricated using hot-press sintering Ti3AlC2 and 2024Al powders. The effect of Ti3AlC2 precursor additions (10, 20 and 30 vol.%) on microstructure and mechanical properties of Al3Ti-TiC/2024Al composites were investigated. It was found that Ti3AlC2 decomposed into submicron TiC particles at 950 °C, while Al atoms reacted with Ti to form Al3Ti. In-situ Al3Ti and submicron TiC were homogeneously distributed in 2024Al matrix. The high temperature tensile and compressive behavior of the in-situ Al3Ti-TiC/2024Al composites was tested in the temperature range of 25–400 °C. The results indicated that the tensile and compressive properties of the material showed temperature dependence. The 20 vol.% Ti3AlC2/2024Al composite exhibit a higher tensile yield strength of 368 MPa with a noticeable elongation of 5.4% at room temperature compared to the pure 2024Al (tensile yield strength is 146 MPa with elongation of 8.5%). At 300 and 400 °C, the tensile yield strength of the as-sintered 30 vol.% Ti3AlC2/2024Al composite was determined to be 176 and 126 MPa, increased by 96% and 293%, respectively, compared with that of pure 2024Al alloy. The excellent tensile property of Al3Ti-TiC/2024Al composites can be ascribed to the synergistic strengthening effect in term of dislocation density, load transfer and dispersion strengthening.

Fabrication of TiC-graphene dual-reinforced self-lubricating Al matrix hybrid nanocomposites with superior mechanical and tribological properties

TiC-graphene dual-reinforced Al matrix hybrid nanocomposites (AMHNs) were synthesised by powder metallurgy. Microstructures, compressive and tribological properties of the AMHNs with different fractions of graphene nanoplatelets (GNPs) were studied and compared with Al2024 alloy, and TiC or GNPs singly reinforced Al composites. The results show the microstructures and distributions of TiC and GNPs are homogenised with the increasing content of GNPs. The compressive properties and wear resistance of the composites are improved efficiently by synergistic influences of TiC and GNPs. Significantly, Al-5.0 wt% TiC-1.0 wt% GNPs has the most superior compressive properties and highest wear resistance with a wear rate of 4.62 × 10−4 mm3/Nm, which is a 94.4% reduction compared with that of unreinforced Al alloy.

Microstructure and mechanical behavior of TiCN reinforced AlSi10Mg composite fabricated by selective laser melting

Although Al alloys have been extensively used for additive manufacture, TiCN reinforced Al composites have rarely been investigated for the feasibility of additive manufacture. In this study, TiCN reinforced AlSi10Mg composite was fabricated by selective laser melting (SLM). The key SLM process parameters, including laser power, scanning speed, as well as hatch spacing were optimized through design of experiment (DOE) and the effects of these parameters on relative density of SLMed AlSi10Mg - 5 vol% TiCN composite were investigated. In addition, the effect of T6 heat treatment after SLM processing on microstructure and mechanical properties of AlSi10Mg - 5 vol% TiCN composite was also studied. Research results show that the optimal SLM parameters are laser power of 370 W, scanning speed of 1760 mm/s, and hatch spacing of 0.063 mm, corresponding to the maximum relative density of 98.5% for SLMed AlSi10Mg - 5 vol% TiCN. Noticeable diffusion of Al and Si elements from matrix to TiCN particles occurs while there is no observed new phase formation between TiCN and Al matrix during SLM process, which enhanced the bonding strength between the TiCN and AlSi10Mg matrix. As compared with the SLMed pure AlSi10Mg, AlSi10Mg–TiCN shows apparently higher hardness, ultimate tensile strength and compression strength due to the significant refinement of AlSi10Mg matrix and the strengthening effect from TiCN particles.

Microstructure and Mechanical Properties of AlSiTiCrNiCu Particles Reinforced Al6061 Composites by SPS and HPS Process

Microstructure and Mechanical Properties of AlSiTiCrNiCu Particles Reinforced Al6061 Composites by SPS and HPS Process

Microstructure and Mechanical Properties of Ti3alc2 Triggered In-Situ Al3ti Reinforced Al6061 Composites Fabricated by Ultrasonic Assisted Casting

Microstructure and Mechanical Properties of Ti3alc2 Triggered In-Situ Al3ti Reinforced Al6061 Composites Fabricated by Ultrasonic Assisted Casting