TiC Nanoparticles Research Articles

Development of WE43/TiC surface composites using friction stir processing: a parametric study

Surface composites of WE43 Mg alloy reinforced with TiC nanoparticles were successfully fabricated using friction stir processing. The effects of various tool profiles, tool rotation, and transverse speeds on the metallurgical and mechanical properties of as-received and WE43/TiC composites were comprehensively investigated. The dispersion of TiC nanoparticles was uniform throughout the stir zone. The square tool at 1700 rev min−1 rotational speed and 60 mm min−1 transverse speed produced the finest grain structure in the composites, exhibiting maximum microhardness (151.7 Hv), maximum nano-hardness (1.596 GPa), maximum elastic moduli (36.54 GPa), and minimum wear rate (0.0279 mm3 min−1). Conversely, a square tool at 800 rev min−1 and 60 mm min−1 transverse speed produced the best mechanical properties in the WE43 alloy.

Microstructure and properties of TiC/Fe24Ni24Co24Mn18 high-entropy composite with exceptionally low coercivity

It is challenging to achieve good combinations of excellent mechanical properties and low coercivity (≤200 A/m) in typical soft magnetic alloys. In this work, TiC/Fe24Ni24Co24Mn18 high-entropy composite (HEC) prepared by mechanical alloying (MA) and spark plasma sintering (SPS) was produced to achieve good combinations of strength-ductility synergy and low coercivity. After MA, the TiC/Fe24Ni24Co24Mn18 HEC powders were composed of a main face-centered cubic (fcc) phase and some body-centered cubic (bcc) phase. Following SPS, the bulk TiC/Fe24Ni24Co24Mn18 HEC consisted of a fcc phase with nanosized TiC. In detail, the HEC showed multilevel heterogeneous microstructure, i.e., ultra-fine fcc grains (∼0.38 µm), micron-sized fcc grains (∼1.49 µm), and uniform dispersion of the in-situ formed TiC nanoparticles (∼98 nm) in ultra-fine fcc grains. The bulk TiC/Fe24Ni24Co24Mn18 HEC exhibits a high tensile yield strength of ∼1167 MPa and an exceptionally low coercivity of ∼100.5 A/m, suggesting an outstanding combinations of mechanical and magnetic properties. Compared with previously reported Fe-Co alloys or high entropy alloys (HEAs), the TiC/Fe24Ni24Co24Mn18 HEC shows a significantly enhanced yield strength while maintaining a relatively low coercivity, primarily resulting from the heterogeneous microstructure caused by the in-situ formed TiC.

Investigations on weld joints of 7075 alloy with Al–5Mg–1Zn composite fillers by arc welding

In this work, the semisolid stirring casting assisted ultrasonic treatment and multi-pass rolling methods were applied to fabricate TiCp/Al–5Mg–1Zn filler materials for tungsten inert gas welding of 7075-T651 aluminum alloy. After welding, various performances and microstructures of the as-weld samples were studied via multifarious electron microscopy and extensive tests. As a result, the TiC nanoparticles which distributed uniformly minished the size of α-Al grains and modified secondary phase owing to the heterogeneous nucleation and retardation of growth. The hardness and tensile strength of joints were enhanced as TiC particles were added, compared to those of 5183 commercial fillers. Besides, both the stress corrosion cracking and intergranular corrosion susceptibility of the weld joints were reduced.

Solving the problem of solidification cracking during additive manufacturing of CrMnFeCoNi high-entropy alloys through addition of Cr3C2 particles to enhance microstructure and properties

In this study, TiAl and Cr3C2 particles were added to a high-entropy CrMnFeCoNi alloy through powder mixing and selective laser melting (SLM) with the aim of acquiring both high SLM processibility and an excellent combination of high strength and ductility with a post-process aging treatment. By only adding 4 at.% TiAl particles into CrMnFeCoNi, a number of cracks were found in as-printed samples for the processing conditions under investigation, promoted by a considerable increase in solidification range and gradient in the late stage of solidification. However, further addition of 2.5 at.% Cr3C2 particles into (CrMnFeCoNi)96(TiAl)4 reduced the solidification range and gradient, allowing to successfully suppress hot cracking. The as-printed (CrMnFeCoNi)96(TiAl)4 samples are characterized by γ grains each containing a group of cells oriented along a similar direction, with the matrix decorated by a small number of nano-sized Al2O3 and σ particles and the cell boundaries with segregated Ti. The addition of Cr3C2 transformed the segregated Ti at the cell boundaries into discrete TiC nanoparticles. On aging at 650 °C, a high density of long-range ordered domains with considerable B2 and σ precipitates formed. Compared to the SLM-processed CrMnFeCoNi, the as-printed (CrMnFeCoNi)96(TiAl)4 displays a reduced 0.2% yield strength and significantly reduced ductility due to the presence of cracks. Conversely, the as-printed (CrMnFeCoNi)96(TiAl)4 + Cr3C2 samples showed a slightly enhanced yield strength and considerably improved UTS. Aging significantly improves both strength properties while maintaining the good ductility. The long-range ordered domains and precipitation clearly are effective in impeding dislocation motion and can be considered to be the prime source of the increased strength of the dual-particle containing alloy.

Discarded water hyacinth/pineapple fibers and carbon/innegra fabrics and TiC nanoparticles reinforced UV resistant polyester composites

The widespread utilization of plant cellulose fiber-inorganic fillers-synthetic fabric-reinforced laminates is the current trend in the research field. This investigation studies the effect of chemically treated and untreated water hyacinth/pineapple leaf, titanium carbide nanoparticles, Innegra, and carbon fabric reinforcement on the physical, mechanical, and thermal characteristics of ultra-violet resistant polyester hybrid composites. The chemically treated and untreated water hyacinth/pineapple leaf fibers were examined from Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD), differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), scanning electron microscope (SEM) and found that chemically treated fibers have an excellent interlocking bond with TiC nanoparticles, Innegra, carbon fabric, and polyester matrix. The maximum tensile, flexural, interlaminar shear, impact strength, and shore hardness also affirmed good interfacial bonding of fillers and textiles within the matrix as examined from SEM micrographs. The present investigation also determines the forecasting of the approaches and performance of artificial neural network (ANN) to model the material characteristics of fabricated polyester hybrid composite. Furthermore, the ANN model was more accurate and a valuable technique to optimize the material characteristics of the developed polyester hybrid composite.

Dynamic mechanical properties of nanoparticle-enhanced aluminum alloys fabricated by arc-directed energy deposition

The nanoparticle-enhanced aluminum alloys fabricated by arc-directed energy deposition (Arc-DED) have gained much attention due to their improved microstructure and enhanced mechanical properties, and are expected to be applied in aerospace, defense, and marine fields. The dynamic properties of nanoparticle-enhanced aluminum alloys are required in the aforementioned fields. In this work, the dynamic behaviors of AA7075 and TiC/AA7075 samples fabricated by Arc-DED in as-built and heat-treated states are investigated by Split-Hopkinson pressure bars tests with the strain rates of 2000–5000 s−1 at room temperature. The results show that adding TiC nanoparticles improve the dynamic properties of aluminum alloys, especially their performance after heat treatment. The improved performance can be attributed to the refined grain and the generated strengthening phase. The metallographic structure shows that the adiabatic shear band (ASB) is first generated with an increase in the strain rate. Then, cracks appear along ASB, leading to the final shear failure. A modified Johnson-Cook constitutive model is proposed based on the strain softening and strain rate softening effects. The results obtained by the proposed model agree with the experimental results. This work is the first to study the dynamic behavior of aluminum alloys fabricated by Arc-DED, which has potential value for applicating aluminum alloys in various industries.

TiC nanoparticles supported on free-standing carbon nanofibers enabled high-performance Lithium–Sulfur batteries

Lithium–sulfur (Li–S) batteries hold great promise for substituting current energy-storage technologies owing to their exceptional advantage in energy density. The main challenge in developing practical Li–S batteries is the lack of efficient sulfur host which can simultaneously suppress the shuttle effect and improve the redox kinetics. Polar host materials manifest chemisorptive properties for localizing the mobile polysulfide intermediates, being promising in inhibiting the shuttle effect; however, their poor intrinsic conductivity hinders their role in enhancing the redox kinetics of subsequent conversion reactions. In this regard, a conductive polar host material is highly desirable for efficient and long-life Li–S batteries. Herein, we design and develop a free-standing sulfur host consisted of carbon nanofibers decorated with titanium carbides nanoparticles (TiC/CNFs) for high performance Li–S batteries. Benefiting from the intrinsic chemical polarity and high electric conductivity of TiC, the chemisorption and conversion kinetics of lithium polysulfides are simultaneously promoted, leading to the greatly enhanced battery performance. For example, the S@TiC/CNFs composite cathode retains a high capacity of 672 mA h g−1 after 1000 cycles and an excellent rate performance of 938 mA h g−1 at 5 C. Impressively, even at a super high sulfur loading of 7 mg cm−2, the TiC/CNFs can retain a capacity of 5 mA h (630 mA h g−1) after 100 cycles, highlighting the advantages of the polar conductive sulfur host design for efficient conversion of lithium polysulfides.

Effect of nano-TiC/TiB2 particles on the recrystallization and precipitation behavior of AA2055-TiC+TiB2 alloys

In this study, particle-reinforced aluminum matrix composites (PRAMCs) of 2055 Al–Cu–Li alloy were prepared with nano-sized TiB2+TiC particles, and electron probe microanalyzer (EPMA), differential scanning calorimetry (DSC), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to investigate the recrystallization and aging behavior of 2055 + TiB2+TiC alloy. The relationship between TiB2+TiC nanoparticles and the T1 strengthening phase during aging was investigated, and the promotion effect of nanoparticles on the T1 phase during aging was explained by the stored energy and mismatch in the coefficient of thermal expansion (CTE). The grain size of as-cast 2055, 0.5, and 1.0 alloys were 112 μm, 87 μm, and 68 μm, respectively. The TiB2+TiC nanoparticles were found to hinder the development of α-Al dendrites in solidification and refine the grains. The recrystallization behavior during solid solution treatment was mainly a particle stimulated nucleation (PSN) mechanism, and TiB2+TiC nanoparticles enhanced the recrystallization resistance. The number density of T1 phase in the pre-deformed 2055 + TiB2+TiC alloy was 452 ± 12/μm−2 with an average size of 73 ± 3 nm, which was finer than 2055 alloy, resulting from the retention of more dislocations or CTE effects at the TiB2 or TiC interface in the deformed 0.5 or 1.0 alloy. These factors cause Cu atoms to aggregate and provide favorable conditions for T1 phase precipitation. Compared with 2055, the ultimate tensile strength of the 0.5 sample was increased from 424 MPa to 455 MPa under condition A and from 498 MPa to 550 MPa after pre-deformation. This study can be used as a reference for improving the mechanical properties of Al–Li alloys.

Cracking inhibition and strengthening of FeCrAlY alloy through addition of TiC nanoparticles during laser melting deposition

FeCrAlY alloy is one ideal candidate for nuclear fuel cladding. Laser melting deposition (LMD) provides a new method for its preparation. To solve the cracking problem as well as to strengthen the alloy, TiC nanoparticles were added during the LMD process. The results show that 4 wt% TiC addition can fully suppress crackings by prompting columnar to equiaxed grain transition. When TiC addition is 6 wt%, the alloy has the finest average grain size of 17 μm, which is nearly 13 times smaller than that without TiC addition. TiC addition also prompts the escape of gas in the molten pool, thus reduces the porosity of the alloys. Without TiC addition, the alloy contains Y-rich heterogeneous structured particles, including Y–O, Y–O–Al–Cr, and Y–O–Al–Cr–Fe particles. After adding TiC, other Y–O–Al–Cr, Y–Al, and C–O–Cr–Fe particles can also be observed. TiC particles mainly have flower-like/granule and plate-like shapes, which correspond to primary and eutectic particles, respectively. With 8 wt% TiC addition, the alloy has good mechanical properties with yield strength of 488 ± 25 MPa, ultimate tensile strength of 749 ± 47 MPa, and an elongation of 15 ± 2%, which are close to those prepared by traditional thermo-mechanically deformation processes.

Hydrogen-assisted one-pot synthesis of ultrasmall TiC nanoparticles enhancing hydrogen cycling of sodium alanate

Sodium alanate, NaAlH4, has great potential as a hydrogen carrier but suffers from sluggish kinetics and poor reversibility caused by high energy barriers. Transition metal-based catalysts are especially effective in reducing kinetic energy barriers for hydrogen cycling of NaAlH4. Herein, we demonstrate a facile fabrication of TiC nanoparticles with 2–4 nm in size supported on carbon (nano-TiC@C). The resultant product consists of approximately 49.2 wt% of TiC and 50.8 wt% of C, and exhibits high and stable catalytic activity for hydrogen storage process of NaAlH4. The 7 wt% nano-TiC@C-containing NaAlH4 releases 5 wt% H2 starting from 65 °C and reabsorbs all released hydrogen at 30 °C under 100 bar H2, outperforming NaAlH4 modified by commercial TiC nanoparticles (∼50 nm in size). The enhancement is related to the ultrasmall size and high reactive activity of as-synthesized TiC nanoparticles. Moreover, the weak electronegativity of C prevents the formation of Na-based by-products, which are often observed in oxide and halide-containing systems. This finding sheds light on how to design and synthesize high-performance catalytic additives for light-metal hydride-based hydrogen storage materials.

Microstructure and mechanical properties of TiC nanoparticles reinforced 7075 aluminium alloy fabricated by oscillating laser-arc hybrid additive manufacturing

In this work, TiC nanoparticles (TiCps) reinforced 7075 aluminium alloy was fabricated via an oscillating laser-arc hybrid additive manufacturing process. To show the beneficial effect of TiCps addition on microstructure and mechanical properties, a conventional 7075 aluminium alloy was also manufactured for comparison. Upon the addition of TiCps, remarkable grain refinement was achieved with a decrease in average grain size from 111.8 to 12.5 µm, and grain boundary segregation was alleviated. It was also found that many secondary phases precipitated at the grain interior in the deposit with TiCps. Owing to the refined microstructure and favourable precipitation, as-deposited 7075 aluminium alloy with TiCps showed enhanced tensile properties of ultimate tensile strengths of 346 and 355 MPa along scanning and build directions.

Correlating topographical characteristics of relaxed layer to tribology in Cu-Gr-TiC composite system

The copper graphite composites are often being applied as bearing materials in various industries. In present investigation, the correlation between the topographical characteristics of relaxed layer to tribology in Cu-Gr-TiC composite system has been investigated. For this purpose, the flake powder metallurgy approach was used to fabricate Cu-Gr-TiC composites and the tribology of these composites was studied under lubricating (synthetic SAE 20W40 motor oil) condition. Variable loads of 10 N–70 N, sliding velocities of 0.75 m s−1–3 m s−1, and sliding distances of 2000 m–8000 m were the test parameters for sliding wear of composites under lubricating conditions. The worn surfaces were examined using SEM and EDS while topographical parameters were studied by AFM. The other properties like mechanical and physical properties were also studied for the sintered samples to better correlate the overall results of surface topography and tribology. The tests depict the successful fabrication of the composites. The composite having 4.5 wt% TiC particles exhibit maximum hardness and least wear and CoF under lubricating environment. The results of sliding wear test conducted under lubrications revealed that rise in the concentration of nano TiC particles in the matrix improves the composite’s tribological performance. The mechanism of wear for pure copper sample is abrasion whereas for TiC particle reinforced composite is smooth ploughing and delamination. The surface topographical parameters that are average surface roughness, area peak to valley height and skewness depicted less roughness values and better load bearing capacity for 4.5 wt% TiC reinforced Cu-Gr sample. The fabricated TiC reinforced copper graphite composites could be utilized as bearing materials in automotive industries.

Study on nano-treating of Al-Mg-Si-Cu alloys with TiC nanoparticles

The 6xxx series wrought aluminum alloys (Al-Mg-Si-Cu) provide good formability and high strength potential, especially with high Cu additions. However, the large freezing ranges of these alloys often cause hot cracking susceptibility in solidification-based processes, such as casting, welding, and 3D printing. In this work, nano-treating, which is to tune the manufacturability and microstructure of metals by a small addition of nanoparticles, was applied to Al-Mg-Si-Cu alloys during casting. This study shows that nano-treating can effectively refine microstructure, eliminate hot cracking, and promote the dissolution of alloying elements. Tensile tests showed that nanoparticles enable strengthening. An extensive study on the TiC nanoparticle effect on Al-Mg-Si-Cu with various Mg and Si contents was conducted. This work provides valuable insights for rational design of nano-treated Al-Mg-Si-Cu alloys to achieve optimal combination of strength and ductility.

Low Velocity Impact Behaviour of Composite Laminates Containing TiC and ZrC Nanoparticles in Resin System

Composite structures utilized in defence and aerospace applications might be subjected to impacts due to bird strike, tool dropping and bullet penetration. One of the approaches to this problem is to add nano tubes and nano particles to resin systems in order to improve bonding between fibres and matrix materials. Different nano-particles or nano-tubes of clays, alumina, silica, carbon and graphene have been analysed in composite systems in the literature so far because of the improved mechanical properties. In this study, the low velocity impact behaviour of the aramid fibre reinforced epoxy composite plates, containing two new nano-particles of TiC and ZrC which are not studied formerly, are searched experimentally. After the low velocity impact tests, it is concluded that plates containing titanium carbide nano-particles and zirconium nano-particles yielded 19 % and 4 % respectively less penetration in comparison with particle free plates. In other words, titanium carbide nano-particles contained plates showed more resistance against the impact by 19 % against to particle free plates. These results showed that TiC and ZrC nano particles might be also good contributors for the impact resistance of composite structure.

Rapid synthesis of nano-TiC particles by microwave heating method

Nanosize titanium carbide (TiC) particles were fabricated by microwave heating at 1100 °C for 10 min using carbon and tetrabutyl titanate as raw materials. The as-sintered precursor was prepared using the sol-gel method. The phase composition, morphology and microwave heating behavior of the heated products were investigated. It was found that TiC particles can be synthesized in a closed capsule of SiO2 with the combined action of high temperature and gaseous products. TiC particles with an average diameter of 50 nm can be synthesized through microwave heating at 1100 °C for 10 min. Higher temperature and longer holding time would lead to re-oxidation and the coalescence of as-formed TiC products. This work demonstrates that this rapid and low-temperature preparation method of nanosize TiC particles has potential application for industrial production.

Large-size ultra-high strength-plasticity aluminum alloys fabricated by wire arc additive manufacturing via added nanoparticles

Wire arc additive manufacturing (WAAM) is a potential technology gradually applied in the aerospace, automobile, and military fields due to its advantages of high deposition efficiency, low manufacturing cost, and unrestricted manufacturing space. However, it is still challenging to fabricate large-size high-performance aluminum alloys using the WAAM method. Here we introduced TiC nanoparticles into the AA7075 wire to improve the performance of Al–Zn–Mg–Cu alloys fabricated by WAAM. TiC nanoparticles tended to be incorporated with the second phases on the grain boundary and strengthened these phases. Besides, TiC nanoparticles can as the heterogeneous nucleation sites for the Al matrix due to the small lattice mismatch between them, resulting in refined grain. Finally, the large-size TiC/AA7075 part was fabricated by optimized manufacturing processes. Compared to AA7075 samples, the TiC/AA7075 samples showed fine equiaxed grains and strengthened second phases, as well as superior (strength ∼ 435 ± 10 MPa, elongation ∼ 7.8 ± 0.8% for the deposited state) and isotropic mechanical properties. The outstanding properties are comparable to those of heat-treated Al–Zn–Mg–Cu alloys fabricated by WAAM in existing studies. This method can be widely applied in the WAAM of aluminum alloy to improve the microstructure, and it provides a novel strategy for manufacturing large-size high-performance aluminum alloy.

THE INFLUENCE OF PARTICLE SIZES AND THE TITANIUM CARBIDE QUANTITY ON THE PROPERTIES AND STRUCTURE OF THE AL-CU SYSTEM ALLOYS

An analysis of the casting process and structure - formation mechanism of aluminum alloys of the Al-Cu-TiC system with high specific strength is performed. The advantages and features of using titanium carbide as an alloying component in order to create nanoscale composite materials (CM) are considered. The results of experiments for the production of CM with a homogeneous structure of Al+5%Cu+ TiC are shown. TiC nanoparticles in the parent melt are described. optimal size ratios and additive ratios of titanium carbide particles in the parent alloy are substantiated.

Non-noble-metal TiC-nanoparticle-promoted charge separation and photocatalytic degradation performance on Bi2O3 microrods: degradation pathway and mechanism investigation.

In the present work, a promising binary TiC/Bi2O3 photocatalyst was obtained via a simple hydrothermal route. In the photodegradation experiment of acid orange 7 (AO7) and tetracycline (TC) irradiated by simulated sunlight, the attachment of TiC nanoparticles on the Bi2O3 microrods leads to an obvious improvement in the photocatalytic removal properties of the Bi2O3 microrods. The optimal removal efficiency of AO7 was achieved by the 7.5%TiC/Bi2O3 sample, which results in about 91.5% dye removal within 75 min of reaction. Meanwhile, the 7.5%TiC/Bi2O3 sample also exhibits favorable photodegradation performance for the degradation of TC, leading to about ∼76.9% TC being degraded after 75 min of irradiation. More importantly, the degradation pathways of AO7 and toxicity analysis of the intermediate products were performed based on liquid chromatography-mass spectrometry detection and theoretical simulation. The superior photocatalytic behavior of the TiC/Bi2O3 composite is attributed to the effective separation and migration of photoexcited electrons and holes in the heterojunction, where the TiC nanoparticles act as an acceptor of photoexcited electrons.

Nanoparticle-enabled increase of energy efficiency during laser metal additive manufacturing

The low energy efficiency of the laser metal additive manufacturing (AM) process is a potential sustainability concern for large-scale industrial production. Explicit investigation of the energy efficiency for laser melting requires the direct characterization of melt pool dimension and vapor depression, which is very difficult due to the opaque nature of the molten metal. Here we report the direct observation and quantification of effects of the TiC nanoparticles on the vapor depression and melt pool formation during laser powder bed fusion (LPBF) of Al6061 by in-situ high-speed high-energy x-ray imaging. Based on the quantification results, we calculated the laser melting energy efficiency (defined here as the ratio of the energy needed to melt the material to the energy delivered by the laser beam) with and without TiC nanoparticles during LPBF of Al6061. The results show that adding TiC nanoparticles into Al6061 leads to a significant increase of laser melting energy efficiency (114% increase on average, 521% increase under 312 W laser power, 0.4 m/s scan speed). Systematic property measurement, simulation, and x-ray imaging studies enable us, for the first time, to identify that three mechanisms work together to enhance the laser melting energy efficiency: (1) adding TiC nanoparticles increases the absorptivity; (2) adding TiC nanoparticles decreases the thermal conductivity, and (3) adding TiC nanoparticles enables the initiation of vapor depression and multiple reflection at lower laser power (i.e., lowers the laser power threshold for keyholing). The method and mechanisms of using TiC nanoparticles to increase the laser melting energy efficiency during LPBF of Al6061 we reported here may guide the development of feedstock materials for more energy efficient laser metal AM. • Quantified nanoparticle-enabled energy efficiency improvement. • Achieved significant increase of energy efficiency by nanoparticles. • Identified mechanisms of nanoparticle-enabled energy efficiency improvement. • Revealed effects of nanoparticles on vapor depression and melt pool evolution.

The development of laser powder bed fused nano-TiC/NiTi superelastic composites with hierarchically heterogeneous microstructure and considerable tensile recoverable strain

In this study, we fabricated the TiC nanoparticles decorated NiTi-based superelastic composites via laser powder bed fusion (LPBF) technology. Different from reactionlessness between TiC and NiTi in the conventional processes, high energy density of laser beam triggered strong diffusion behavior of carbon atoms from TiC nanoparticles and resulted in the precipitation of TiCx and attendant Ni-rich even Ti-rich intermetallics. Interestingly, these nanoprecipitates distributed along the intricate network of connected dislocations, architecting a novel submicron-scale cellular reinforcement structure and facilitating the formation of a hierarchically heterogeneous microstructure. The migration and distribution of TiC nanoparticles as well as the forming mechanism of the submicron cellular reinforcement structure were then elaborated. The study indicated laser scanning speed had significant influence on the distribution of TiC nanoparticles, the size of cellular structure and the matrix grain orientation. At the optimized parameter, the LPBF-fabricated nano-TiC/NiTi composites exhibited a weak orientation texture along the building direction, finer cellular structure and a considerable steady recoverable strain of 2.3% at a maximum tensile loading of 300 MPa.