Effect Of TiC Nanoparticles Research Articles

A Novel Design to Enhance the Tribological Properties of High‐Cr Hot Work Die Steel via Trace TiC Ceramic Nanoparticles

Excellent wear properties can improve the service performance and service life of high‐Cr hot work die steels. Herein, an innovative method is proposed to introduce TiC nanoparticles into the matrix of high‐Cr hot work die steels, and the effects of TiC nanoparticles on the microstructure and wear resistance of high‐Cr hot work die steels are investigated. In isothermal spheroidizing and quenching and tempering heat treatments, the TiC nanoparticles refine the granular pearlite, tempered martensite, and precipitates, which are attributed to the improved nucleation rates by increasing the number of heterogeneous cores. In sliding wear tests, the nanoparticle‐reinforced high‐Cr hot work die steels show higher wear resistance under the temperatures of 20 and 400 °C. The better wear properties of high‐Cr hot work die steels are because the substrates are strengthened and toughened, the dislocations are hindered, the mating areas are partially separated, and external loads are withstood by nanoparticles. This work shows new prospects for the development of high‐Cr hot work die steels with excellent wear performance.

Enhanced strength-ductility in a cast basket-weave-structured α-Ti alloy by adding TiC nanoparticles

The addition of TiC nanoparticles induced a refined basket-weave structure, replacing coarse α colonies in cast Ti-2.5Al. Thus, the yield strength and elongation of Ti-2.5Al+TiC are increased by 46.3 % and 57.6 %, respectively. The effect of TiC nanoparticles on the grain refinement and tensile properties is more pronounced than the addition of elemental C.

Effect of TiC nanoparticles on microstructure and corrosion resistance of laser cladding Al-CNTs composite coatings on AZ31 alloy

ABSTRACT Al-CNTs composite coatings were successfully prepared on AZ31 alloy using laser cladding (LC). The effect of TiC nanoparticles on microstructure and corrosion resistance of the LC Al-CNTs and Al-TiC-CNTs composite coatings were investigated. The LC composite coatings were composed of α-Mg solid solution phase and β-Al12Mg17, Mg2Al3, Mg32(Al,Zn)49 and TiC compound phases. A sound metallurgical bonding interface was produced between the LC composite coatings and AZ31 alloy. The surface microhardness and corrosion resistance of the LC composite coatings, which were gradually decreased with increasing the content of carbon nanotubes (CNTs) and TiC nanoparticles, were significantly enhanced compared to those of the AZ31 alloy. The LC Al-CNTs (99 wt% Al + 1 wt% CNTs) composite coating exhibits excellent surface microhardness and corrosion resistance. The mean surface microhardness, self-corrosion potential and self-corrosion current were 266.4 HV, −1.233 V and 2.55 × 10−5 A, which were 426.2%, 78.9% and 16.5% of the AZ31 alloy, respectively.

Increased tensile strength and elongation of the Ni–Fe based polycrystalline cast superalloy via the trace addition of TiC nanoparticles

In this work, a Ni–Fe based cast superalloy (K214) containing 0.02 wt% TiC nanoparticles was fabricated by the vacuum induction melting, and the effects of TiC nanoparticles on the microstructure and tensile properties of the alloys were investigated. The trace addition of TiC nanoparticles effectively refined the as-cast grains, promoted the coarsening of secondary dendrite arms, and reduced microsegregation. The yield strength, ultimate tensile strength and elongation at room/elevated temperatures were simultaneously improved, which could be ascribed to reduced microsegregation and refined γ′ precipitates. This work provides a strategy for the effective improvement in the mechanical properties of cast superalloys fabricated by the conventional casting process.

Effect of TiC nanoparticles on microstructural and tribological properties of Cu-TiC nano-composites

The present study has investigated the role of the addition of TiC nanoparticles on the microstructural, mechanical, physical, and metallurgical properties of the Cu-TiC nanocomposites. A Powder metallurgy route was used to fabricate the samples. Cold compaction of powders was done at 480 MPa which was followed by sintering at 950°C. Wt.% of TiC was varied from 0% to 20%. A Pin-On-Disc tribometer was used to carry out the wear and friction tests. SEM and EDS techniques were used to explicate the morphology and microstructures of worn surfaces and to comprehend the underlying wear mechanism. The fabricated samples were investigated against the applied normal load (10, 20, and 30 N), sliding speed (0.5, 1.0, and 1.5 m/s), and sliding distance (900, 1800, and 2700 m). The results revealed that the Hardness and tensile strength were improved by 88.76% and 37.26% respectively due to the addition of TiC and were maximum for Cu-20%TiC while the relative density shows the reverse trend. Further, it was found that wear resistance and coefficient of friction were improved by 87.18% and 51.85% respectively as a function of nano-TiC content. The presence of oxide layers and mechanically mixed layers are detected from worn surface analysis which modulates the tribological behavior of the contact.

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.

Optimization of sintering parameters for fabrication of Al2O3/TiN/TiC micro-nano-composite ceramic tool material based on microstructure evolution simulation

In order to design and fabricate a new Al2O3/TiC/TiN micro-nano-composite ceramic tool material with high mechanical properties, a microstructure evolution model of ceramic tool material during sintering process was established to optimize the sintering parameters based on cellular automata. Furthermore, the effects of TiC nano-particles on mechanical properties of the prepared material were investigated. Toughening and strengthening mechanisms of TiC nano-particles were revealed by examining SEM images of microstructure and crack propagation. The results indicated that the mechanical properties increased first and then decreased as TiC nano-particles volume fractions of prepared material rose. When Al2O3, TiC, TiN micro-particles and TiC nano-particles were 60%, 20%, 10% and 10%, respectively, ceramic material prepared exhibited outstanding mechanical properties with Vickers hardness of 20.8 GPa, flexure strength of 881.4 MPa, and fracture toughness of 7.8 MPa m1/2 obtained at the sintering temperature of 1650 °C with holding time for15min through the simulation. The main strengthening and toughening mechanisms of the prepared materials could be attributed to transgranular fracture, intergranular fracture, crack deflection and crack bridging.

TiC nanoparticles enhanced ultrasonic treatment for microstructure refinement of A356 alloy

In this work, the effect of TiC nanoparticles (NPs) inoculation and ultrasonic treatment (UT) on the refining behavior of A356 alloy was investigated. Compared with the base and sonicated samples, dendritic grains and eutectic Si phases were simultaneously refined with extra NPs addition. Microstructure analysis revealed that these NPs had two distribution types, i.e., intragranular distribution (within the primary α-Al grains) and extragranular distribution (inside the eutectic cells). Considering the ultrasonic cavitation effects and good crystallographic matching between TiC and Al, it is suggested that the finer and uniform grain structure can be attributed to the higher nucleation density facilitated by the activated TiC NPs during solidification. Meanwhile, the enriched NP-induced growth restriction mechanisms are proposed to explain the further refinement and modification in eutectic Si.

Exploring the reinforcing effect of TiC and CNT in dual-reinforced Al-matrix composites

Aluminum-matrix composites dual-reinforced by TiC/CNTs were fabricated using a combination of mechanical milling and spark plasma sintering (SPS) techniques. Composition, structure and morphology of the samples were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and high resolution transmission electron microscopy (HRTEM). Through TEM, nano-scale uniform distribution of TiC nanoparticles around CNTs was observed. In addition, it was shown that hybridization of TiC nanoparticles with CNTs significantly enhanced the mechanical properties of the dual-reinforced composites. In this regard, improvements of 60% and 33% in nano-hardness as well as 149% and 85% in micro-hardness were achieved by doping 1 wt% TiC/CNT into Al matrix in comparison with pure Al and Al/CNT composite, respectively. Apart from fine ceramic particle strengthening, it was found that CNTs can enhance mechanical properties of Al/CNT composites through their defects, crack-bridging and restriction of dislocations motion. The results showed that the effect of TiC nanoparticles and carbon nanotubes can be considered as a main strengthening mechanism for the dual TiC/CNT reinforced Al composites.

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.

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.

Effect of TiC nanoparticles on the microstructure and mechanical properties of gas tungsten arc welded aluminum joints

In the present study, TiC/Al composite fillers of gas tungsten arc (GTA) welding with different contents of TiC nanoparticles were successfully fabricated by accumulative roll bonding (ARB). The purpose of ARB was to create a uniform distribution of TiC nanoparticles in the fillers and to form a good interfacial bonding between the aluminum matrix and TiC nanoparticles. The microstructure, mechanical properties and fracture surface morphology of the welds were investigated. It was found that TiC nanoparticles decreased the grain size of the primary α-Al phase due to the augmented nucleation and retarded growth. The tensile strength and hardness of weld improved with increasing TiC nanoparticle content. The improvement in the mechanical properties was attributed to the uniform distribution of TiC nanoparticles and grain refinement. Therefore, it can be concluded that the TiC/Al composite filler can serve as a suitable filler for GTA welding of aluminum and its alloys.

More weather studies help aviation, fire fighting and lake level work

In order to design and fabricate a new Al2O3/TiC/TiN micro-nano-composite ceramic tool material with high mechanical properties, a microstructure evolution model of ceramic tool material during sintering process was established to optimize the sintering parameters based on cellular automata. Furthermore, the effects of TiC nano-particles on mechanical properties of the prepared material were investigated. Toughening and strengthening mechanisms of TiC nano-particles were revealed by examining SEM images of microstructure and crack propagation. The results indicated that the mechanical properties increased first and then decreased as TiC nano-particles volume fractions of prepared material rose. When Al2O3, TiC, TiN micro-particles and TiC nano-particles were 60%, 20%, 10% and 10%, respectively, ceramic material prepared exhibited outstanding mechanical properties with Vickers hardness of 20.8 GPa, flexure strength of 881.4 MPa, and fracture toughness of 7.8 MPa m1/2 obtained at the sintering temperature of 1650 °C with holding time for15min through the simulation. The main strengthening and toughening mechanisms of the prepared materials could be attributed to transgranular fracture, intergranular fracture, crack deflection and crack bridging.