Addition Of TiC Nanoparticles Research Articles

Fabrication of reinforced Al–Mg composite by TiC particles via FSW: Microstructure and tribology study

In this article, wear and microstructure behaviors of dissimilar Al–Mg joints made by friction stir welding (FSW) with the addition of TiC nanoparticles under different welding parameters were investigated. Optimal joining conditions were achieved by a combination of various rotational and traverse speeds and the best microstructure evolution, mechanical properties, and tribological behaviors were achieved for specimens joined at rotational and traverse speeds of 850 rpm and 50 mm/min, respectively. It was shown that the TiC particles play a prominent role in the microstructure modification and enhanced mechanical properties of weld samples due to the recrystallization process and pinning effect. The maximum hardness and strength values of 241 HV and 168 MPa, respectively were obtained for the weld sample made by optimal condition. The friction coefficient and wear volume loss for weld samples fabricated at 850 rpm and 50 mm/min is comparatively less compared to other conditions due to the highest grain refinement, homogenous distribution of particles, and highest hardness characteristics. The major wear happened because of adhesion, abrasion, plastic deformation, delamination, and oxidation.

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.

Dual beam laser fusion-brazed Ti6Al4V/AA7075 dissimilar lap joint: Crack inhibition via inoculation with TiC nanoparticles

Severe hot cracks defects formed in the aluminum weld metal during laser fusion brazing (LFB) Ti6Al4V/AA7075 dissimilar lap joint. Herein, TiC nanoparticles were used to optimize the microstructure of aluminum weld metal. The wettability of molten aluminum alloy on the titanium was improved due to the increased laser absorptivity of aluminum with the addition of TiC nanoparticles. In contrast to the aluminum weld metal of the LFB joint with coarse cellular and dendrite grains, the LFB-TiC joint had a refined microstructure, consisting of equiaxed grains with segmented secondary phase, both of which intrinsically inhibit the intergranular hot cracking. Most of the TiC nanoparticles are dispersed in the precipitated phase or adsorbed on the boundary surface between the matrix phase and the Mg(Zn,Cu,Al) 2 precipitated phase. The average thickness of TiAl 3 IMC (intermetallic compound) increased to a maximum of 1.73 μm, ensuring interfacial bonding reliability. Benefiting from the inhibition of cracks and the synergy effect of grain refinement strengthening and load-bearing strengthening, the LFB-TiC joint exhibits elevated mechanical performance, the equivalent tensile strength and displacement increased from 289.8 MPa and 0.35 mm of the LFB joint to 487.7 MPa and 0.58 mm of the LFB-TiC joint. The enhancement in ductility is mainly attributed to the grain boundary modification caused by the dispersed TiC nanoparticles. The results show that Ti/Al lap joint with excellent mechanical properties can be obtained by laser fusion brazing method with proper microstructure control. • The hot cracking characteristics of Ti6Al4V/AA7075 laser fusion brazing joint was revealed. • TiC nanoparticles were used to inhibit the hot crack defects in the dissimilar lap joint. • The modified aluminum weld had a refined microstructure, consisting of equiaxed grains with segmented secondary phase. • The crack-free LFB-TiC joint shows improved mechanical properties with the equivalent tensile strength of 487.7 MPa.

Wire-Arc Additive Manufacturing of Nano-Treated Aluminum Alloy 2024.

With high strength and good fatigue resistance, Al-Cu alloys such as AA2024 are widely used in the aerospace and automotive industries. However, the system's susceptibility to hot cracking and other solidification defects hinders its development in metal additive manufacturing (AM). A nano-treated AA2024 deposition, with the addition of TiC nanoparticles, is successfully additively manufactured without cracks. Microstructural analysis suggests nanoparticles not only mitigate the hot cracking sensitivity but also significantly refine and homogenize grains, resulting in an average size of 23.2 ± 0.4 μm. Microhardness profiles show consistent mechanical performance along the build direction, regardless of cyclic thermal exposure. Finally, excellent tensile strength and elongation up to 428 MPa and 7.4% were achieved after heat treatment. The combined results show a great promise of nano-treating in high-strength aluminum AM.

Grain refinement and strengthening of 316L stainless steel through addition of TiC nanoparticles and selective laser melting

In this work, strengthening of 316L stainless steel was achieved through addition of 1 and 3 wt% TiC nanoparticles. The TiC nanoparticles and 316L powders were mixed using low energy ball milling and then processed by selective laser melting. The grains are significantly refined from 16.8 μm to 6.9 μm with the addition of 3 wt% TiC nanoparticles. Addition of 1 and 3 wt% TiC nanoparticles remarkably increased yield strength (694 MPa and 773 MPa) and ultimate tensile strength (888 MPa and 988 MPa). Meanwhile, the tensile elongation was kept at a high level (47% and 32%). The strength enhancement primarily results from Orowan strengthening by the nanoparticles, and the reduction of ductility is related to the suppression of twinning induced plasticity.

Effectively mitigated macro-segregation and improved tensile properties of twin-roll casting Al-Cu strips via the addition of TiC nanoparticles

In this work, Al-5Cu and TiC/Al-5Cu strips were fabricated by vertical-type twin-roll casting (TRC), and the effects of TiC nanoparticles on the Al-Cu strips were investigated. The minor addition of TiC nanoparticles refined the grain structure, increased the Cu concentration in the α-Al dendrites and effectively mitigated the center macro-segregation of the as-cast strip, which could be due to the heterogeneous nucleation effect and the solute diffusion control of the TiC nanoparticles. The yield strength, ultimate tensile strength, and uniform elongation of the as-cast, as well as T6 treated Al-5Cu strip with the addition of TiC nanoparticles were simultaneously improved owing to fewer residual Cu-rich phases, refined θ′ precipitates, and finer grain structure. This work provided a strategy for the effective control of macro-segregation and producing high-formability alloy strips by the TRC process.

Effect of TiC Nanoparticles on the Mechanical Properties of a K465 Superalloy

In this paper, the effects of TiC nanoparticles on the mechanical properties of the K465 superalloy were investigated. The elongation of the K465 alloy was improved by adding TiC nanoparticles without ultimate tensile strength reduction. Adding TiC nanoparticles can also effectively refine grain size and influence dendrite morphology. Moreover, the addition of TiC nanoparticles also led to the change of carbide morphology. The improvement of elongation was attributed to the refined grains and changed the morphology of carbides.

Nanoparticle additions promote outstanding fracture toughness and fatigue strength in a cast Al–Cu alloy

Fatigue resistance and fracture toughness are essential to the reliability of castings during service. Reducing microporosity in cast alloys is a crucial issue for improving their fatigue strength and fracture toughness. Here we report a significant reduction in microporosity of a cast aluminum-copper alloy developed using in situ TiC nanoparticle additions coupled with a stir-casting method. The addition of TiC nanoparticles is found to improve the interdendritic feedability of liquid metal and as a result reduces the volume fraction of microporosity by two orders of magnitude compared to a conventionally cast Al–Cu alloy. This method, which is mechanistically associated with a pore-dominated process, acts to significantly improve the fatigue strength, fracture toughness and uniform elongation of the cast Al–Cu alloy to values which, to the best of our knowledge, represent the highest ever achieved for a cast aluminum alloy.

Electrolytic deposition of TiC nanoparticles/Ag composite films and their optical properties

TiC nanoparticles/Ag composite films were successfully prepared on an indium tin oxide (ITO) substrate through co-electrodeposition, using the Ag plating solutions with minor addition of TiC nanoparticles, followed by heat treatment in vacuum. The X-ray diffractometer, scanning electron microscope and UV–Vis spectrophotometer were used to characterise phase composition, morphologies and optical properties of as-fabricated films, respectively. Experimental results show that only TiC and Ag phases are identified for the TiC nanoparticles/Ag composite films and TiC nanoparticles are incorporated tightly and uniformly on the surface of the composite films, without obvious clustering. The results of optical property test reveal that the TiC nanoparticles/Ag composite films have similar optical properties as thick silver films perforated with nanohole arrays, which will pave the way towards numerous potential applications of Ag nanohole arrays.

Effect of TiC nano-particles on the mechanical properties of an Al-5Cu alloy after various heat treatments

In this paper, the effects of TiC nano-particles on the mechanical properties of Al-5Cu alloy were investigated. Adding TiC nano-particles can effectively refine grain size and secondary dendritic arm. The ultimate tensile strength, yield strength and elongation of the Al-5Cu alloy in each of the three states (i.e. as-cast, solid-solution state and T6 state) were also improved by adding TiC nano-particles. Moreover, the elastic-plastic plane-strain fracture toughness (KJ) and work of fracture ( wof) of Al-5Cu containing TiC were significantly higher than those of Al-5Cu without TiC after aging for 10 h. The addition of TiC nano-particles also led to finer and denser ′ precipitates.

Effect of a nano-sized TiC particle addition on the flow-assisted corrosion resistance of SA 106B carbon steel

Carbon steel with dispersed nano-sized TiC ceramic particles was fabricated by the ex-situ introduction of the particles into the melt, with the flow-assisted corrosion (FAC) resistance then investigated in the presence and absence of TiC nanoparticles using a once-through type of FAC loop test. From the potentiodynamic polarization curves, the current density at any given anodic potential was decreased and the open-circuit potential was increased by the addition of TiC nanoparticles. In addition, when the nano-sized TiC particles were added, the FAC rate was 1.38 times lower than that of carbon steel without TiC nanoparticles, indicating an improvement of the FAC resistance due to the homogeneous distribution of the TiC reinforcing nanoparticles.

Dual functions of TiC nanoparticles on tribological performance of Al/graphite composites

In this study, the effect of TiC nanoparticles as a reinforcement on the mechanical and tribological properties of Aluminum-based self lubricating composite was investigated. The microstructure, relative density, hardness, and tribological properties of Al/graphite and Al/TiC/graphite composites were examined as a function of graphite content. The tribo-surfaces of the samples were analyzed using SEM and EDS elemental mapping. The results indicated that the addition of TiC nanoparticles not only decreased the wear rate and coefficient of friction of the composites, but also facilitated the formation of a stable graphite layer at longer sliding distances and high sliding velocities by forming a durable graphite/TiC composite on the tribo-surface. Therefore, the stability of graphite layer can be considered as a possible cause for decrease in wear rate of the Al/TiC/graphite composite.

Sintering behaviour of NiAl–xTiC nanostructured composite powders (x = 0, 1, 3, 6 and 10 vf%) during hot pressing

NiAl–xTiC nanostructured composite powders [x = 0, 1, 3, 6 and 10 volume fraction per cent (vf%)] were produced by high energy ball milling of Ni, Al and nano-TiC powders. Sintering of prepared nanostructured NiAl powder using hot pressing resulted in an ultrafine grained NiAl intermetallic with a high relative density, while addition of TiC nanoparticles seriously inhibited grain growth and slightly decreased the relative density of nanostructured NiAl. It was found that the addition of nano-TiC reinforcement up to 10 vf% resulted in stabilisation of nanostructured NiAl in nanocomposite products.