Simultaneous enhancements in damping and static dissipation capability of polyetherimide composites with organosilane surface modified graphene nanoplatelets

Polyetherimide (PEI) possesses excellent thermal resistance and advanced mechanical properties, for which it has been used as interior materials in various transportation structures. Multifunctional PEI nanocomposites, in particular, with high damping properties and satisfactory static dissipation capability, will be more significant for those applications. In this study, PEI/graphene nanoplatelet (GNP) nanocomposites were fabricated via solution processing. Effects of GNP loading and surface silanization of GNPs on damping capacity and static dissipation properties were studied. The addition of the GNPs effectively increased the storage modulus of PEI, especially storage modulus at higher temperature (200 °C). The silanization of GNPs, on one hand, improved the dispersion quality; on the other hand, provided strong interfacial bonding with PEI matrix, which benefited the stress transfer within the composites. The superior damping capacity enhancements for the resulting nanocomposites are: with the loading of 3.0 wt% silanized GNP, the storage modulus of PEI increased approximately 4 times and 200 times at 30 °C and 200 °C, respectively, and the damping factor is 3 times higher than PEI. In addition, with the addition of 3.0 wt% GNPs, both low electrical resistivity (∼10⁶ Ω∗cm) and low dielectric constant (∼7) were realized, corresponding to excellent volume static dissipation capability, however, silanization resulting in good interfacial bonding did not cause invisible impact on the electrical and dielectric properties of the nanocomposites. The superior damping capacity and static dissipation property make them suitable for intra-structure materials for airplane and transportation.     

Exfoliation of organoclay nanocomposites based on polystyrene-block-polyisoprene-block-poly(2-vinylpyridine) copolymer: Solution blending versus melt blending

Exfoliated nanocomposites based on polystyrene-block-polyisoprene-block-poly(2-vinylpyridine) (SI2VP triblock) copolymer were prepared by solution blending and melt blending. Their dispersion characteristics were investigated using transmission electron microscopy, X-ray diffraction, and small-angle X-ray scattering (SAXS). For the study, SI2VP triblock copolymers with varying amounts of poly(2-vinylpyridine) (P2VP) block (3, 5, and 13 wt%) and different molecular weights were synthesized by sequential anionic polymerization. In the preparation of nanocomposites, four different commercial organoclays, treated with a surfactant having quaternary ammonium salt, were employed. It was found from SAXS that the microdomain structure of an SI2VP triblock copolymer having 13 wt% P2VP block (SI2VP-13) transformed from core-shell cylinders into lamellae when it was mixed with an organoclay. It was found further that the solution-blended nanocomposites based on a homogeneous SI2VP triblock copolymer having 5 wt% P2VP block (SI2VP-5) gave rise to an exfoliated morphology, irrespective of the differences in chemical structure of the surfactant residing at the surface of the organoclays, which is attributable to the presence of ion-dipole interactions between the positively charged N⁺ ion in the surfactant residing at the surface of the organoclay and the pyridine rings in the P2VP block of SI2VP-5 and SI2VP-13, respectively. Both solution- and melt-blended nanocomposites based on microphase-separated SI2VP-13 having an order-disorder transition temperature (T_ODT) of approximately 210 °C also gave rise to exfoliated morphology. However, melt-blended nanocomposite based on a high-molecular-weight SI2VP triblock copolymer having a very high T_ODT (estimated to be about 360 °C), which was much higher than the melt blending temperature employed (200 °C), gave rise to very poor dispersion of the aggregates of organoclay. It is concluded that the T_ODT of a block copolymer plays a significant role in determining the dispersion characteristics of organoclay nanocomposites prepared by melt blending.     

Role of polymer-clay interactions and nano-clay dispersion on the viscoelastic response of supercritical CO2 dispersed polyvinylmethylether (PVME)-Clay nanocomposites

Clay dispersion and polymer-clay interactions play a key role in producing property enhancements in nanocomposites; yet characterizing them in complex polymer-clay systems is often a challenge. Rheology can offer insights into clay dispersion and clay-polymer interactions. We have investigated the viscoelastic response for a series of supercritical CO₂ (scCO₂) processed polyvinylmethylether (PVME)/clay nanocomposites with varying polymer-clay interactions and nano-clay dispersion. PVME is used in this study because it is highly swellable in scCO₂, thereby enabling processing of PVME/clay mixtures without the presence of a co-solvent. Since PVME and natural clay are water-soluble, highly dispersed PVME-clay nanocomposites were prepared using water, followed by lyophilization in the presence of polymer. In this ‘weakly interacting’, but highly dispersed systems, with clay loadings above the percolation threshold, terminal behavior was observed in the linear viscoelastic moduli (i.e. no low frequency plateau is observed). When the nanocomposites were processed in scCO₂, with 15 wt% of 30B and I.30P, the WAXD patterns of the resultant nanocomposites were largely comparable, indicating partial dispersion, with intercalation peaks. However, the rheology of these two nanocomposites were significantly different despite similar inorganic volume loading (4 vol%). Even with less dispersion compared to the water-based system, the low-frequency moduli were significantly more enhanced, accompanied by a plateau, and a cross-over frequency shift. Neglecting the small differences in the actual clay content between these clays (4-5 vol% of inorganic matter), this suggests that rheology may be sensitive to strong interactions between the clay surfactant and the polymer. Therefore, polymer-clay interactions and clay-clay interactions may both be important in the ability to sustain a “so-called” percolated network, rather than just clay dispersion.     

A solution blending route to ethylene propylene diene terpolymer/layered double hydroxide nanocomposites

Ethylene propylene diene terpolymer (EPDM)/MgAl layered double hydroxide (LDH) nanocomposites have been synthesized by solution intercalation using organically modified LDH (DS-LDH). The molecular level dispersion of LDH nanolayers has been verified by the disappearance of basal XRD peak of DS-LDH in the composites. The internal structures, of the nanocomposite with the dispersion nature of LDH particles in EPDM matrix have been studied by TEM and AFM. Thermogravimetric analysis (TGA) shows thermal stability of nanocomposites improved by ≈40 °C when 10% weight loss was selected as point of comparison. The degradation for pure EPDM is faster above 380 °C while in case of its nanocomposites, it is much slower.     

Enhanced electrical properties of polycarbonate/carbon nanotube nanocomposites prepared by a supercritical carbon dioxide aided melt blending method

Polycarbonate/carbon nanotube (CNT) nanocomposites were generated using a supercritical carbon dioxide (scCO₂) aided melt blending method, yielding nanocomposites with enhanced electrical properties and improved dispersion while maintaining the aspect ratio of the as-received CNTs. Baytubes^® C 150 P CNTs were benignly deagglomerated with scCO₂ resulting in 5 fold (5X), 10X and 15X decreases in bulk density from the as-received CNTs. This was followed by melt compounding with polycarbonate to generate the CNT nanocomposites. Electrical percolation thresholds were realized at CNT loading levels as low as 0.83 wt% for composites prepared with 15X CNT using the scCO₂ aided melt blending method. By comparison, a concentration of 1.5 wt% was required without scCO₂ processing. Optical microscopy, transmission electron microscopy, and rheology were used to investigate the dispersion and mechanical network of CNTs in the nanocomposites. The dispersion of CNTs generally improved with scCO₂ processing compared to direct melt blending, but was significantly worse than that of twin screw melt compounded nanocomposites reported in the literature. A rheologically percolated network was observed near the electrical percolation of the nanocomposites. The importance of maintaining longer carbon nanotubes during nanocomposite processing rather than focusing on dispersion alone is highlighted in the current efforts.     

Water-soluble polyaniline/graphene prepared by in situ polymerization in graphene dispersions and use as counter-electrode materials for dye-sensitized solar cells

Water-soluble polyaniline/graphene nanocomposites have been prepared via a simple in situ polymerization of aniline in graphene dispersion. TEM measurement confirmed that polyaniline was homogeneously coated on the graphene sheets. The nanocomposites solution can be used for film fabrication by common technology, such as drop coating. When these different polyaniline/graphene nanocomposites were applied as the counter electrode materials for dye-sensitized solar cells, the short-circuit current density and power-conversion efficiency of the devices were measured to be 12.19 mA cm⁻² and 4.46%, respectively, which was comparable to 5.71% for the cell with a Pt counter electrode under the same experimental conditions.     

Robust and wear resistant in-situ carbon nanotube/Si3N4 nanocomposites with a high loading of nanotubes

Highly homogenous carbon nanotube (CNT)/silicon nitride (Si₃N₄) nanocomposites with high CNTs loadings, up to 22 vol.%, are developed through the in-situ synthesis of CNTs on the ceramic powders, and further densification using the spark plasma sintering technique. The CNTs dispersion degree, the composite density, and their properties, especially the tribological ones, are evaluated and compared with those obtained for nanocomposites processed by the ex-situ method based on the mixing of nanotubes and ceramic powders in a solvent media. Fully dense in-situ 12 vol.% CNTs nanocomposites are 87% and 65% more wear resistant than monolithic Si₃N₄ materials and ex-situ nanocomposites, respectively, in the latter case due to the higher nanotubes dispersion and better mechanical properties attained by the in-situ process. These new in-situ CNTs nanocomposites present multifunctionality and are promising for emerging applications, especially for gasoline direct injection systems.     

Regenerated cellulose nanocomposites reinforced with exfoliated graphite nanosheets using BMIMCL ionic liquid

Green nanocomposites of regenerated cellulose/exfoliated graphite nanosheets films with low nanofiller loadings were prepared using environmentally benign 1-butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid. X-ray diffraction revealed well developed intercalated nanocomposites. The tensile strength and Young's modulus of the prepared nanocomposites were increased by 97.5% and 172% respectively when 0.75 wt.% and 1 wt.% exfoliated graphite nanosheets were added. The results were validated using the Halpin–Tsai model. The exfoliated graphite nanosheets were unidirectionally aligned in the regenerated cellulose parallel to the surface of the nanocomposites as revealed by transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Also, the TEM and FESEM revealed uniform dispersion of the exfoliated graphite nanosheets and good interaction between the nanofillers and the matrix. The addition of the exfoliated graphite nanosheets enhanced the thermal stability and reduced the water absorption and diffusivity of the nanocomposites.     

Preparation of high-impact polystyrene nanocomposites with organoclay by melt intercalation and characterization by low-field nuclear magnetic resonance

Recycled high-impact polystyrene nanocomposites with organoclay were prepared. Clay of the smectite group (montmorillonite) with two types of intercalated compounds was used (Viscogel S4 and Viscogel S7). The polymer nanocomposites were prepared by melt intercalation, applying two shear intensities in a twin screw extruder. The nanostructured materials obtained were characterized by NMR relaxometry, X-ray diffraction, thermogravimetric analysis, melt flow index and mechanical analyses. The results showed that the nanostructured materials presented a mixed intercalated/exfoliated morphology. The organophilic clay, Viscogel S7, generated polymer nanocomposites with better dispersion and distribution (at low concentrations) than those produced with the Viscogel S4. The shear rate was effective for dispersion of the nanoparticles. The materials processed at 600 rpm showed better dispersion than those processed at 450 rpm. The characterization techniques chosen were effective. They were complementary and permitted comparison among the polymer nanocomposites. The use of low-field NMR relaxometry allowed measurement of the spin–lattice relaxation time of hydrogen (T₁H), which provided more precise information on the mobility of the materials, thus complementing and explaining the results obtained by X-ray diffraction.     

Co-continuous nanostructured nanocomposites by reactive blending of carbon nanotube masterbatches

Masterbatches of reactive polymers containing carbon nanotubes are used to prepare nanocomposites by reactive blending. By mixing masterbatches of low molecular-weight amino-terminated polyamide-6 (PA6) containing ～10 wt% or ～17 wt% of multi-walled carbon nanotubes (MWNT) with maleic anhydride functionalized polyethylene (PE*) at temperatures above melting of PA6 it is possible to obtain fine and homogeneous dispersions of carbon nanotubes. In the PA6 concentration range explored, from 19 wt% to 37 wt%, nanostructured co-continuous blend morphologies are achieved. Selective extractions show that a high amount of graft copolymer PE*-g-PA6 is synthesized during mixing. The swelling experiments in selective solvents demonstrate co-continuous blend morphologies. Electron microscopy confirms good quality of MWNT dispersion and shows structures on mesoscopic scales. Fine dispersion of carbon nanotubes and the matrix co-continuity concur to yield a unique combination of properties such as solvent resistance, electrical conductivity, mechanical strengthening and ductility.     

Effect of montmorillonite dispersion on flammability properties of poly(styrene-co-acrylonitrile) nanocomposites

Poly(styrene-co-acrylonitrile)/Cloisite 20A (95/5) nanocomposites, having various spatial dispersion levels of the clay, were prepared with controlling clay concentrations in a solvent by the coagulation method. X-ray diffraction, transmission electron microscopy and laser scanning confocal microscopy were used to characterize the structure and morphology of the nanocomposites on a nano-scale and on a micro-scale. Quantitative analysis of clay spatial dispersion in the nanocomposites based on the laser scanning confocal microscopy images was conducted from three different perspectives: 1) clay spatial distribution; 2) the non-clay-occupied domain size; and 3) the relationship between the frequency and intensity of pixels in the images. The results from these quantitative methods indicate that nanocomposites with different spatial dispersion levels of clay in the poly(styrene-co-acrylonitrile) matrix were obtained. Evidently, the ?d₀₀₁ data from the X-ray diffraction was found to be not useful in measuring the clay dispersion in the nanocomposites. The effect of clay dispersion on the flammability properties of the nanocomposites and relevant mechanism of the clay dispersion having influence on flammability were also investigated. In radiant gasification experiments at 50 kW/m², the best clay dispersion yielded a 32% reduction in peak mass loss rate, as compared to the nanocomposites with the worst dispersion.     

Montmorillonite-carbon nanocomposites with nanosheet and nanotube structure: Preparation,characterization and structure evolution

In this study, the preparation of montmorillonite (Mt)-polyvinyl alcohol (PVA) nanocomposites (MtPVAN), and the formation of corresponding Mt carbon nanocomposites with nanosheet and nanotube structures were investigated. MtPVAN was prepared by solution intercalation combined with the dispersion method of ultrasonic radiation (UR) and mechanical stirring (MS). XRD analysis showed that the MtPVAN with d₀₀₁ at 2.16 nm were successfully obtained with optimum mass ratio of 1:1.5 (Mt:PVA) and solid content of 10%. Then, the Mt-carbon, nanocomposites (d₀₀₁ = 1.56 nm) with sandwich structure was prepared by carbonizing MtPVAN at 400 °C in nitrogen atmosphere for 3 h; and Mt-carbon nanosheets or nanotubes with carbon content of 5.10% was obtained by exfoliating the sandwich-like Mt-carbon nanocomposites with further airflow pulverization process. The average diameter and the thickness of the Mt-carbon nanosheets was about 2 μm and 10 nm, respectively; while the diameter of the nanotubes was 7–80 nm. The mechanism of the formation and the structure evolution of the Mt-carbon nanocomposites were also discussed.     

Rheological behaviors and electrical conductivity of epoxy resin nanocomposites suspended with in-situ stabilized carbon nanofibers

Epoxy resin nanocomposites suspended with carbon nanofibers (CNFs) have been prepared. A bifunctional coupling agent, 3-aminopropyltriethoxysilane, is used to treat the acid oxidized fibers. The dispersion quality of the CNFs with and without surface modification is monitored by an oscillatory rheological investigation. The addition of fibers is observed to influence the rheological behaviors of the suspensions drastically. Newtonian fluid behavior disappears as the fiber loading increases. A significant increase of the complex viscosity and storage modulus is observed, especially when the temperature increases to 50 °C and 75 °C. In-situ reaction between the amine-terminated functional groups on the silanized fibers and the resin, is justified by the FT-IR analysis and is responsible for the improved fiber dispersion and network formation. A decreased rheological percolation is observed after silanization due to the improved fiber dispersion quality. The electrical conductivity percolation is well correlated to the rheological percolation for the as-received fiber resin suspensions. However, with an insulating organic coating on the fiber surface, the conductivity increases slightly and lacks the correlation to the rheological percolation.     

Solvent-Free One-Pot Synthesis of high performance silica/epoxy nanocomposites

High performance silanized silica/epoxy nanocomposites were prepared through mixing epoxy, tetraethyl orthosilicate (TEOS), (3-aminopropyl)trimethoxysilane (APTMS) and ammonia solution at 50 °C. This all-in-one “Solvent-Free One-Pot Synthesis” results in nanocomposites with uniform dispersion of oval shaped silica nanoparticles and strong adhesion between silica and epoxy matrix. The influence of the synthesis conditions, such as molar ratio of NH₃:TEOS, aging time, curing process and silica content on the thermal mechanical properties of nanocomposites were studied. The silanized silica/epoxy nanocomposite prepared in this study exhibits better thermal mechanical property in comparison with neat epoxy, non-functionalized silica/epoxy and commercialized silica/epoxy systems. The prepared nanocomposite with 3 wt% silanized silica exhibits 20%, 17% and 6% improvements on flexural, tensile and storage modulus over those of neat epoxy, respectively.     

Influence of Matrix Polarity on the Properties of Ethylene Vinyl Acetate–Carbon Nanofiller Nanocomposites

A series of ethylene vinyl acetate (EVA) nanocomposites using four kinds of EVA with 40, 50, 60, and 70 wt% vinyl acetate (VA) contents and three different carbon-based nanofillers—expanded graphite (EG), multi-walled carbon nanotube (MWCNT), and carbon nanofiber (CNF) have been prepared via solution blending. The influence of the matrix polarity and the nature of nanofillers on the morphology and properties of EVA nanocomposites have been investigated. It is observed that the sample with lowest vinyl acetate content exhibits highest mechanical properties. However, the enhancement in mechanical properties with the incorporation of various nanofillers is the highest for EVA with high VA content. This trend has been followed in both dynamic mechanical properties and thermal conductivity of the nanocomposites. EVA copolymer undergoes a transition from partial to complete amorphousness between 40 and 50 wt% VA content, and this changes the dispersion of the nanofillers. The high VA-containing polymers show more affinity toward fillers due to the large free volume available and allow easy dispersion of nanofillers in the amorphous rubbery phase, as confirmed from the morphological studies. The thermal stability of the nanocomposites is also influenced by the type of nanofiller.     

Templated growth of polyaniline on exfoliated graphene nanoplatelets (GNP) and its thermoelectric properties

Polyaniline (PANi)/exfoliated graphene nanoplatelets (GNP) nanocomposites were prepared by in situ polymerization of aniline monomer in the presence of GNP for thermoelectric applications. PANi has a strong affinity for GNP due to π electron interactions, forming a uniform nanofibril coating. A paper-like nanocomposite was prepared by controlled vacuum filtration of an aqueous dispersion of PANi decorated GNP. The Seebeck coefficient of the resulting nanocomposite changes with initial concentration of aniline in the solution as well as the protonation of PANi, reaching as high as 33 μV/K for nanocomposites containing approximately 40 wt% of PANi and with a protonation ratio of 0.2. The presence of GNP improved the electrical conductivity of the nanocomposites to 59 S/cm. As a result, thermoelectric figure of merit ZT of the nanocomposites is 2 orders of magnitude higher than either of the constituents, exhibiting a significant synergistic effect.     

Novel in situ polydimethylsiloxane-sepiolite nanocomposites: Structure-property relationship

A series of novel in situ polydimethylsiloxane (PDMS)-sepiolite nanocomposites were synthesized by anionic ring opening polymerization of octamethylcyclotetrasiloxane. These nanocomposites were characterized by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy, Wide Angle X-Ray Diffraction (WAXD), Transmission Electron Microscopy (TEM), mechanical and dynamic mechanical properties and thermogravimetry. This paper highlights the structure-property relationship of in situ PDMS-sepiolite nanocomposites and a way to improve the mechanical, dynamic mechanical and thermal properties of silicone rubber. Comparison of these physico-mechanical properties with those of the ex situ nanocomposites reflects greater degree of filler dispersion for the in situ nanocomposites. Increasing amount of the filler reduced the size of the crystalline domains in PDMS matrix, which was evident from the X-Ray and the dynamic mechanical analysis. However, the polymer-filler interaction was even more prominent to negate the effect of the deterioration of the properties due to decrease in size of the microcrystallites. The polymer-filler interaction was reflected in the improved mechanical and thermal properties which were the consequences of proper dispersion of the filler in the polymer matrix. The modulus improvement of the rubber-clay nanocomposites was examined by using Guth and Halpin-Tsai model. The temperature of maximum degradation was raised by 167 °C and improvement of 210% in tensile strength and 460% in modulus at 100% elongation was observed. These results were correlated with the data obtained from WAXD and TEM studies.     

Effects of molecular weight,stereo configuration of PLA,and processing on the dispersion of multiwalled carbon nanotubes and properties of corresponding nanocomposites

Multiwalled carbon nanotubes (MWCNTs) were dispersed and distributed via a co-rotating twin-screw extruder (TSE) in high (h)- and low (l)-molecular-weight amorphous and semicrystalline polylactides (PLAs) (aPLA and scPLA, respectively). Effects of PLA molecular weight and D-lactic acid equivalents content (D-content), as well as processing parameters, were examined on the MWCNT dispersion quality in PLA. The effectiveness of the MWCNT dispersion in various PLA matrices was investigated using scanning electron microscopy (SEM) and small-amplitude oscillatory and transient shear flow rheometry in the molten state. The results showed a better dispersion of MWCNTs in the low-molecular-weight PLA grades (aPLAl and scPLAl). In addition, better MWCNT dispersion was observed in aPLA grades when processed at a higher temperature of 190°C than at 150°C. At 150°C, while MWCNT bundles in aPLAl could be broken down, a good dispersion could not be achieved in aPLAh due to the lower molecular mobility at such a temperature. The electrical conductivity of the samples was also shown to increase as the MWCNT dispersion was improved. The existence of crystallites in scPLA-based nanocomposites, however, disrupted the connectivity of the MWCNTs and decreased the final electrical conductivity. The lower molecular weight aPLAl prepared at 190°C showed the highest electrical conductivity (~10⁻⁵ S/m) at a low loading of 0.5 wt.% MWCNTs.     

Effect of incorporation of hafnium diboride nanofibers on thermomechanical properties of carbon fiber–phenolic composites

Carbon fiber/phenolic (C/Ph) composites were modified with different weight ratios of hafnium diboride (HfB₂) nanofibers to apperceive thermomechanical properties of C/Ph–Hf nanocomposites. Mechanical properties, thermal stability, and ablation resistance of C/Ph–Hf nanocomposites were found to be optimum when the weight percentage of HfB₂ was equal to one. Maximum flexural strength and modulus were obtained with 118 MPa and 1.9 GPa for C/Ph–1%Hf nanocomposite, respectively. Increasing the proportion of HfB₂, by delaying the temperature of thermal degradation of nanocomposites, enhanced the thermal stability and residual of C/Ph–Hf relative to C/Ph in both nitrogen and air environments. In the oxyacetylene flame test at 2500°C for 160 s, the optimum mass ablation rate of C/Ph–1%Hf nanocomposites was found to be 0.0150 g/s compared to 0.068 g/s for blank C/Ph, along with reducing the back surface temperature by 51%. The ablation mechanism of C/Ph–Hf nanocomposites after the oxyacetylene torch test was concluded from the derivations obtained from X-ray diffraction, energy dispersion spectroscopy, and microstructure analyses. These clarified that the formation of high-temperature species, such as HfO₂, HfC, and B₄C owing to oxidation of HfB₂ and subsequent reaction products with char, resulted in an increased ablation resistance of the nanocomposites.     

A comprehensive exploration on the development of nano Y2O3 dispersed in AA 7017 by mechanical alloying and hot-pressing technique

The main objective of the present study is to develop AA 7017 alloy matrix reinforced with yttrium oxide (Y₂O₃, rare earth element) nanocomposites by mechanical alloying (MA) and hot pressing (HP) techniques for armor applications. AA 7017+10 vol % Y₂O₃ nanocomposites were synthesized in a high-energy ball mill with different milling times (0, 5, 10, and 20 h) to explore the structural refinement effect. The phase analysis and homogeneous dispersion of Y₂O₃ in AA 7017 nanocrystallite matrix were investigated by X-ray diffraction (XRD), various electron microscopes (HRSEM, and HRTEM), Particle Size Analyzer (PSA), and Differential Thermal Analysis (DTA). The nanostructured powders were hot-pressed at 500 MPa pressure with a temperature of 673k for 1hr. The consolidated sample results revealed significant grain refinement and the enhanced mechanical properties with the function of milling time in which the 20h sample exhibited improvement in the hardness (142 VHN - 260 VHN) and ultimate compressive strength (514 MPa–906.45 MPa) due to effective dispersion of Y₂O₃. The various strengthening mechanisms namely, grain boundary (27.02–32.69 MPa), solid solution (57.21 MPa), precipitate (189.79–374.62 MPa), Orowan (135.68–206.92 MPa), and dislocation strengthening (84.99–149.82 MPa) were determined and correlated to the total strength.