TiC Particles Research Articles

Microstructure and mechanical properties of in-situ nano TiC reinforced Ni-based alloy composites prepared by spark plasma sintering

Carbide dispersion reinforcing has been demonstrated to be an effective way of strengthening metal matrix composites. However, plagued by the nerve-wracking fact that the carbide particles tend to aggregate at the grain boundary of the metal matrix, grow up, and form an incoherent interface with it, their improvement in mechanical strength tends to be limited. In this study, spark plasma sintering (SPS) was used to prepare the bulk alloy Ni20Cr and its composites with different carbides including TiC, SiC, and Ti3SiC2. Plasma leads to discharge and elevates temperature at the interface to melt the Ni20Cr alloy particles locally. When cooled down, the alloy is heterogeneously solidified on the surface of the carbide and builds up a coherent interface with it. Owing to the decomposition of Ti3SiC2 during sintering, it completely transformed into nanosized TiC particles, which are engulfed by the outer melted layer of Ni20Cr and well dispersed within the alloy grains. In comparison to the Ni20Cr alloy, the composite with merely 4 wt% Ti3SiC2 gains over three times enhancement in yield strength to 879 MPa, while keeping a moderate high elongation of 17.8 %. Finite element analysis demonstrated that the combination of SPS and precursor MAX phase of Ti3SiC2, which results in the in-situ precipitation of coherent ultrafine TiC particles in alloy grains, plays the key role in getting a good balance between mechanical strength and ductility for the Ni20Cr matrix composites.

Insight into the Hot Corrosion Behavior of FeMnCrSi/TiC Coatings at 900 °C

This study explores the deposition of an Fe-MnCrSi/TiC coating on 45 steel surfaces using high-velocity arc spraying technology, examining the microstructure and hot corrosion behavior of the resultant layer. The microstructure of the FeMnCrSi/TiC coating primarily consists of an α-Fe (BCC) solid solution, composed of Fe, Mn, Cr, Si, C, and other elements, with a minor presence of β-Fe (FCC) solid-solution phase and unmelted TiC particles. Following 100 h of cyclic 900 °C hot corrosion, Mn on the coating surface preferentially oxidizes, forming a manganese-rich oxide layer. This process reduces the oxygen partial pressure (O2) within the coating, prompting the formation of a dense Cr2O3 layer on the inner side of the oxide layer. Concurrently, the rapid diffusion of Mn and Cr elements triggers the generation of Mn- and Cr-deficient regions at the metal/oxide layer interface, inducing the transformation of the coated metal primary matrix from an FCC + BCC dual phase to an α-Fe (BCC) single phase. After the reaction, the hot corrosion weight gain of the coating reached 12.43 mg/cm2, approximately one-fourteenth of the weight gain of the 45 steel substrates. This weight gain adheres to the parabolic law, suggesting that the FeMnCrSi/TiC coating exhibits excellent corrosion resistance under the given conditions.

Hydrogen trapping and embrittlement of titanium- and vanadium carbide-containing steels after high-temperature hydrogen charging

This work studies the effect of TiC and VC precipitate sizes on hydrogen trapping and embrittlement. Two experimental ferritic HSLA steels containing either TiC or VC carbides for precipitation strengthening are annealed in nitrogen and hydrogen gas. This results in a hydrogen uptake of up to 0.91 and 0.44 wppm in the TiC and VC steels, respectively. TEM and TDS analysis indicate that semi-coherent TiC particles trap hydrogen in misfit dislocations with an activation energy of 43 kJ/mol. Coherent VC particles are suggested to trap hydrogen in interface carbon vacancies, with an energy between 53 and 72 kJ/mol. Carbon vacancies are the likely trapping site in incoherent precipitates, where SIMS imaging confirms that incoherent TiC precipitates trap preferentially near the interface, whereas incoherent VC precipitates trap throughout their bulk. Neither alloy is embrittled in SSRT tests after hydrogen absorption, which shows that these precipitates can be used as both a hydrogen sink and a strengthening mechanism in steels.Graphical abstract

Impact wear resistance of in-situ TiC particles reinforced Mn18Cr2 steel dual-scale architecture composites

In this study, TiC particle-reinforced high-manganese-steel (Mn18Cr2) matrix composites were successfully prepared using an in-situ method, and a millimeter micrometer dual-scale architecture was constructed in the composites to further enhance their mechanical properties. The effects of different moderator contents in the precursor on the size, volume fraction, mechanical properties, and impact wear resistance of the generated TiC particles were primarily investigated. The results showed that the moderator considerably influenced the microstructure and mechanical properties of the composites. As the moderator content increased, the size, volume fraction, mechanical properties, and wear resistance of TiC particles decreased. The optimal comprehensive performance of the composites was obtained when the moderator content was 20 wt%., average TiC particle size was 1.21 μm, volume fraction was 64.9 %, bulk hardness was more than three times that of the matrix, compressive strength was ∼2 GPa, and relative wear resistance was 2.47 times that of the matrix. The main wear behaviors of composites included grooves, microcutting, pits, and plastic deformation. In conclusion, this study guides the design and synthesis of steel matrix composites with tunable in-situ ceramic particle sizes and volume fractions to enhance wear resistance.

Effect of TiC Particles on the Properties of Copper Matrix Composites

Effect of TiC Particles on the Properties of Copper Matrix Composites

Ballistic performance of titanium-based layered composites made using blended elemental powder metallurgy and hot isostatic pressing

Metal matrix composites tiles based on Ti–6Al–4V (Ti64) alloy, reinforced with 10, 20, and 40 (vol%) of either TiC or TiB particles were made using press-and-sinter blended elemental powder metallurgy (BEPM) and then bonded together into 3-layer laminated plates using hot isostatic pressing (HIP). The laminates were ballistically tested and demonstrated superior performance. The microstructure and properties of the laminates were analyzed to determine the effect of the BEPM and HIP processing on the ballistic properties of the layered plates. The effect of porosity in sintered composites on further diffusion bonding of the plates during HIP is analyzed to understand the bonding features at the interfaces between different adjacent layers in the laminate. Exceptional ballistic performance of fabricated structures was explained by a significant reduction in the residual porosity of the BEPM products by their additional processing using HIP, which provides an unprecedented increase in the hardness of the layered composites. It is argued that the combination of the used two technologies, BEPM and HIP is principally complimentary for the materials in question with the abilities to solve the essential problems of each used individually.

The strengthening mechanism of mechanical and tribological properties of TiC-reinforced 316L matrix composites fabricated by selective laser melting

Selective laser melting (SLM) has been proved to be a promising additive manufacturing technique to fabricate high-performance metal matrix composites (MMCs) with unique microstructures. In this study, TiC-reinforced 316 L MMCs were successfully prepared by SLM. The effects of TiC addition on the microstructure evolution, mechanical properties and tribological behavior were systematically investigated to study the strengthening mechanism. The TiC/316 L MMCs fabricated by SLM exhibited a high relative density of over 99.6% and were close to full density. The TiC particles are effectively bonded with the 316 L matrix, serving as a means of dispersion strengthening. In addition, the grains were significantly refined, and the dislocation density was greatly enhanced with the addition of TiC particles, which reinforce the strength of the material. Tensile tests show that the tensile strength of TiC/316 L MMCs increased by 49.9% from 707 to 1060 MPa and yield strength increased by 44.2% from 543 to 783 MPa with 4 wt% TiC. Besides, the tribological behavior of TiC/316 L MMCs was much superior to the pure 316 L. The findings provide a new perspective on ceramic particles reinforced stainless steel MMCs with tailored microstructure and excellence performance.

Densification Behaviours of TiC/Ni Metal Ceramic Alloys Produced by Powder Metallurgy

Ceramic Metallic Alloys of TiC/Ni, Comprising Titanium Carbide with Nickel Contents of 5%, 15%, 30%, and 50%, were Fabricated through Solid-Phase Sintering at 1400°C with a 2-hour Holding Time and a Pressure of 50MPa. This Study Explores the Impact of Nickel Content on the Mechanical and Structural Properties. The Solidification Mechanism between TiC and Ni is Governed by Carbon Diffusion through TiC Particles, Affecting the Morphology of TiC and Carbon Particles in Ni Samples. The Reaction Behavior within the TiC/Ni Alloys was Analyzed, and Microstructural and Mechanical Characteristics were Examined to Evaluate the Influence of Varying Nickel Contents. Results indicate that in all samples, the TiC matrix exhibited a solid solution of the FCC phase. The reaction mechanism of Ti-C-Ni reveals the evolution of solid phase formation with increasing nickel content. As nickel content increases, the mass and size of nickel particles grow, leading to a more uniform and homogeneous structure. At a nickel content of 15%, the samples displayed a bending strength of 1200 ± 50 N, a microhardness of 800 ± 20 (HV 0.1), and a density of 5.6 ± 0.2.

Influence mechanism of solution temperature on microstructure evolution and tensile properties of Ti microalloyed high strength steel CGLC700

The influence mechanism of solution temperature on the strength and toughness of Ti microalloyed steel CGLC700 was studied. The microstructure changes of Ti microalloyed steel were observed by micro-electron microscopy, and the mechanical properties were evaluated by tensile test. The appropriate solution temperature can promote the solid solution of Ti atoms and the formation of small-sized TiN, TiC and other particles, hinder the movement of dislocations, and improve the tensile properties of steel. When the solution temperature is 1240 °C (2#), the grain size of steel is the lowest, the proportion of high angle grain boundary is the highest, and the tensile properties of steel are the best. Ti microalloyed steels increased tensile strength by 4.12%, yield strength by 2.85% and elongation by 28.4%. Too low or too high solid solution temperatures weaken the strengthening effect of the microalloying elements and led to a reduction in the tensile properties of the steel. This can be attributed to the low solid solution of Ti at low solid solution temperatures and the growth of second phase particles and inclusions at too high solid solution temperatures. This study provides a theoretical basis for optimizing the heat treatment process of Ti microalloyed steel.

Crack healing via electropulsing treatment applied to additive-manufactured TiC/316L stainless steel composites

Three coupons of TiC/316L stainless steel composites were fabricated by laser-based directed energy deposition (DED-LB). One coupon is crack-free, and the other two coupons have cracks inside. Electropulsing treatment (EPT) was applied to heal the cracks, with various current densities and 75 pulses on each sample. The cracks with widths of 0–200 μm can be healed by EPT. The microstructure of the healed region consists of refined fractured TiC particles and resolidified fine austenite grains. The EPT is able to potentially be applied to heal the defects or cracks in additive-manufactured metal-matrix composites.

Tribological performance of c-BN/TiC-enhanced NiCrBSi coatings prepared by high-velocity oxy-fuel spraying tested from room temperature to 1000 °C

The c-BN/TiC-enhanced NiCrBSi composite powder and coatings were prepared by spray-drying and high-velocity oxygen-fuel (HVOF) spraying, respectively. The phases, microstructures and tribological performance were studied from room temperature to 1000 °C, and the wear mechanisms of coatings were analyzed and discussed. The results showed that TiC and c-BN distributed evenly in NiCrBSi phase, but with the increase of temperature, c-BN showed a certain degree of aggregation, while TiC particles grew significantly. Therefore, the coating shows good wear resistance at room temperature. As the temperature increased, the wear rate of the coating increased, and the wear resistance decreased, so the maximum wear rate was obtained at 800 °C. However, when the temperature was increased to 1000 °C, a composite enamel layer of oxide and hard phase was generated on the surface of the abrasion marks, which improved the wear resistance of the coating, significantly reducing the wear rate.

Multi-scale hybrid reinforced super duplex stainless steel matrix composites with high strength and ductility via laser powder bed fusion and an in-situ synthesis strategy

The emergence of nanoparticle-reinforced metal matrix composites represents a promising method for efficiently enhancing material strength without significant compromise in ductility. Nevertheless, the homogeneous distribution of nanoparticles in matrix remains a technical challenge. To address this issue, this study designed an advanced method to create a multi-scale hybrid to reinforce super duplex stainless steels (SDSSs) by coupling laser powder bed fusion (LPBF) technique with an in-situ synthesis strategy and optimizing post heat treatment. For as-built composites, both TiCxNy and M23C6 nanoparticles were generated in-situ by the introduction of micron-sized TiC particles into SDSSs, and their microstructure was mainly composed of fine ferrite grains. The post quenching treatment enabled heat-treated composites to possess micro-duplex matrix grains with a multi-scale hybrid, including micron-sized TiC, in-situ sub-micron M23C6 particles, and in-situ TiCxNy nanoparticles. Particularly, the obvious agglomeration phenomenon of in-situ TiCxNy nanoparticles was not observed. In comparison with heat-treated SDSSs (ultimate tensile strength (UTS): ∼839 MPa; uniform elongation (UE): ∼20.6 %), heat-treated composites processed by 1090 °C obtained a higher UTS (∼992 MPa) with only 0.8 % reduction in UE. The great ductility of heat-treated composites was primarily attributed to their relatively high strain hardening rate, facilitated by grain refinement and the formed multi-scale hybrid. The successful creation of a multi-scale hybrid sets the stage for producing high-performance metallic components via LPBF and in-situ strategy.

Effects of Ti addition and wall thickness on microstructure, hardness, and wear properties of spheroidal graphite cast irons

Spheroidal graphite cast irons (SGCIs) have been commonly used in automotive and energy sectors where superior mechanical strength and wear resistance are required. This paper investigated the performance of the SGCIs under severe wear conditions as a function of Ti content and cooling rate. SGCIs alloyed with various Ti content (0, 0.1, 0.2, 0.3, and 0.5 wt%) were produced by green sand-casting process in different section sizes (10, 30, and 50 mm). Ball-on-disk type wear equipment with an Al2O3 ball was used to determine the wear rates of the SGCI samples. With increasing Ti content, up to 45% of nodular graphite turned into vermicular graphite, depending on the Ti addition and section sizes. Carbide precipitation was observed in the matrix due to the carbide-forming effect of Ti. The hardness and wear resistance of the SGCIs were improved by adding Ti owing to the combined effects of increasing pearlite and TiC particles precipitated in the matrix. Thinner-wall castings provided a faster cooling rate, which improved hardness and wear resistance. Alloying with 0.5 wt% Ti decreased the wear rates up to 35%.

Effects of TiC particles on tribological and corrosion resistance of PEO coating on TC4 alloy

To improve wear resistance and corrosion behavior of TC4 alloy, plasma electrolytic oxidation (PEO) was performed in a TiC particle containing electrolyte. Results show that increasing PEO current density is conducive to improving the coating thickness, promoting incorporation of TiC particles, and enhancing wear resistance of the coating. While increasing TiC content in electrolyte reduces PEO coating thickness. Under the optimized condition, where the electrolyte has 2 g L−1 TiC and PEO current density is 5 A dm−2, the derived PEO coating exhibits both high wear resistance and corrosion resistance. Moreover, it is shown that the incorporated TiC particles are more likely to become components in the inner layer of the derived MAO coating.

Effects of TiC addition on the interface stability, microstructure, and mechanical properties of IN718 fabricated by laser direct metal deposition: A combined experimental, DFT and MD study

In this study, we reveal the impact of the addition of TiC in the IN718 superalloys at both atomic and micron scales through density functional theory (DFT), molecular dynamics (MD), and experimental analysis. From the micro scales, the addition of TiC can effectively mitigate the segregation behavior of Nb and Mo atoms, promote heterogeneous nucleation, reduce grain size, and thus improve mechanical properties. From the atomic scales, the effect of alloying elements (Fe, Cr, Mo, Nb, Co) on the stability of the TiC/γ-Ni interface was investigated through first principles. Co-doping interface was more stable than other interfaces by MD calculations, followed by Cr and Fe-doping models. The heat of segregation results inferred that TiC can effectively mitigate the segregation behavior of Nb and Mo atoms in the TiC/γ-Ni interface, it is mutually verified with the experimental results. Furthermore, the interface energy values theoretically illustrated that TiC particles could promote the heterogeneous nucleation of γ-Ni, this behavior of TiC particles was verified by experiment results. This investigation results provide reference information in the study of ceramic particle reinforced alloys at atomic and micron scales.

Direct evidence of melting and decomposition of TiC particles in laser powder bed fusion processed 316L-TiC composite

Recent advancements have shown the effectiveness of strengthening 316L with TiC particles addition through the laser powder bed fusion (LPBF) process. However, the question remains whether TiC undergoes decomposition into Ti and C atoms, primarily because of the challenges associated with measuring C at low concentrations. In this study, we employed atom probe tomography (APT) to provide evidence of decomposition by observing the presence of Ti and C atoms in the 316L matrix. The fast cooling rate of the LPBF process results in the supersaturation of Ti and C in the 316L matrix. Adding 3 wt% TiC particles increased the yield strength of LPBF-processed 316L from 599 MPa to 832 MPa. The subsequent annealing treatment resulted in the formation of more TiC nanoparticles as a result of precipitation from the supersaturated Ti and C in the 316L matrix. Consequently, the yield strength was further enhanced to 959 MPa after annealing at 700 °C for 1 h. This study marks the first direct demonstration of the decomposition of TiC in metal matrix composites.

Key reaction steps in the combustion synthesis of Ti3SiC2/SiCp ceramic composites using titanium reactant in foil form: Microstructural evidence

The paper is devoted to the microstructural evidence of key reaction steps in the combustion synthesis of SiC particulate reinforced Ti3SiC2 ceramic matrix composites from multilayer stack of titanium foils and polymer films filled with SiC and TiC particles. It was found that the primary interaction step results in the formation of intermediate product layer, which exhibits a duplex microstructure consisting of a continuous Ti5Si3 matrix embedded with islands of TiC0.52 particles. Next, in the combustion step, a significant rise in the sample temperature leads to complete melting of the titanium foils. The molten titanium infiltrates then the area occupied by SiC and TiC particles. Finally, the peritectic reaction between Ti-rich melt and carbide particles results in the formation of a Ti3SiC2 MAX phase matrix. An excess quantity of SiC particles remains uniformly entrapped within the matrix, eventually giving a microstructure of particulate-reinforced ceramic matrix composite.

Promising composites for wear resistant load-bearing implant applications: Low elastic moduli of β Ti–Nb alloy reinforced with TiC particles and/or TiB whiskers

Despite β-type Ti alloys achieving a low elastic modulus, metallic implants generally exhibit poor wear resistance. To address this issue, in-situ Ti-based matrix composites (TMCs) are considered due to their strong bonding at the matrix/reinforcement interface. While TiC particles and TiB whiskers are common reinforcements for in-situ TMCs, limited research combines their effects with the low elastic modulus of Ti alloys. Here, we present a novel approach using arc-melting on Ti–40Nb alloy with 5 vol% additions of NbC, NbB2, and B4C. Respectively, three TMCs were obtained with the β-type Ti–Nb matrices reinforced individually with TiC particles, TiB whiskers, and hybridized with both. The produced TMCs exhibited the same passive behavior of the unreinforced Ti–40Nb alloy. However, tribocorrosion resistances were improved, as TMCs achieved nobler potentials during sliding than the unreinforced alloy (−0.5 and −0.9 V, respectively). Notably, the TiB-reinforced and the hybrid reinforced TMCs displayed minimal wear damage, while the TiC-reinforced TMC achieved a remarkable low elastic modulus of approximately 73 GPa. This study introduces promising alternatives for wear-resistant load-bearing implant applications.

The effect of asymmetric rolling on the microstructure and properties of Al–Cu–Li–TiC/TiB2 alloys

The study systematically investigated the impact of asymmetric rolling (AR) and subsequent aging treatment on the microstructure and mechanical properties of Al–Cu–Li–TiC/TiB2 alloy. The average grain size of the as-cast A0 and A1 alloys was 249.87 μm and 38.2 μm, respectively. The grain size was significantly refined by TiC and TiB2 particles. The texture of A0 and A1 samples after symmetric rolling (SR) was dominated by the β-fiber, including typical Copper, S, and Brass rolled textures. The core of the board has a relatively high proportion of Brass texture. The grain size of the AR sheet increases gradually from the surface to the center, with the middle to fast (MF) layer having the largest grain size. The middle to slow (MS) layer has the highest strength of Goss texture, indicating that the shear bands formed by AR are mostly located in the MS layer. A significant amount of T1 precipitate was observed in the aged sample, and a new T1 phase composite with a thickness of 1.426 nm was found in the AR sample. The structure of the composite consists of two parallel T1 precipitates with Al–Cu layer atoms at the center. The growth behavior of the composite is such that the new T1 precipitate adheres to one side of the original T1 precipitate and grows parallel in the form of T1P-T1. In the T85 state, the A0SR samples exhibit a yield strength, tensile strength, and elongation of 503 MPa, 518 MPa, and 7.5%, respectively. The A1-SR samples exhibit a yield strength, tensile strength, and elongation of 520 MPa, 526 MPa, and 8.2%, respectively. The A0-AR samples exhibit a yield strength, tensile strength, and elongation of 553 MPa, 572 MPa, and 4.5%, respectively, while the A1-AR samples exhibit a yield strength, tensile strength, and elongation of 580 MPa, 605 MPa, and 5.2%, respectively. The increase in yield strength can be attributed to fine-grained strengthening, precipitation strengthening, and Orowan strengthening brought about by nano TiC/TiB2 particles.

Surface Characteristics of Vacuum-Plasma-Sprayed Reinforced Stainless Steel Coatings with TiC Particles

Fe-based coatings reinforced with TiC particles exhibit outstanding properties and are widely recognized as highly promising coatings or components with superior performance. In the present study, composite materials using a powder mixture of AISI 316 stainless steel and TiC particles were deposited by vacuum plasma spraying onto a S235 low alloyed steel substrate. The coating and the base material were characterized in terms of microstructure and surface properties. The metallographic analysis of the deposited coating revealed the uniform distribution of the TiC into the stainless steel matrix. The results show that the presence of tungsten carbide particles improved the hardness and tribological properties of the composite coating compared with the S235 base material. The wear resistance of the coating was approximately seven times higher than that of the low alloyed steel substrate. The electrochemical corrosion resistance of the coating in chloride media was much higher than that of the base material.