Effect Of TiC Particles Research Articles

Effect of TiC Particles on the Properties of Copper Matrix Composites

Effect of TiC Particles on the Properties of Copper Matrix Composites

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.

Probing the texture transition sequence of near β titanium matrix composites by observing the uneven hot deformation microstructure

This study is focused on the sequence of texture transformation and uneven microstructure evolution during hot compression of 2 vol% TiC/Ti-4Al-1Sn-2Zr-5Mo-8 V-2.5Cr composites. After hot compression, the uneven microstructures, including local high deformed region (HDR) and low deformation region (LDR), are observed by EBSD. The area and width of elongated grains decrease in the HDR, but the LDR shown the opposite trend as temperature and deformation rate rise. The sequence of texture transformation with different lattice rotation axis during hot compression of TMCs is established based on lattice rotation during continuous recrystallization (CDRX). At a low temperature (850 °C), initial as-cast (110)//CD (ζ fiber) texture first changes to (111)//CD (γ fiber) texture, and then stable (001)//CD texture (θ fiber: {001} 〈0−10〉). The rotation axis is the 〈110〉 direction on the {001} plane. Low-temperature stable (001)//CD texture can be further changed into near-(110)//CD with varied rotation axis of 〈111〉 direction on the {110} plane if the deformation temperature is sufficiently high and strain rate is low (for instance, at 940 °C with 0.001 s−1). Meanwhile, the effect of TiC particles on β matrix texture is limited, and an orientation relationship of [−1−11]β//[−1−10]TiC1¯1¯1β//1¯1¯0TiC is identified between TiC particles and the β matrix.

Microstructure and wear resistance of direct laser-deposited TiC-enhanced aluminum-based composite coating for brake discs

To prepare a wear-resistant coating on the surface of aluminum alloy to replace cast iron to realize the lightweight of the urban rail transit brake disc is a promising and low-cost method. In this work, aluminum-based composite coatings reinforced with TiC particles of different mass percentages (20 %, 40 %, 60 %) were successfully prepared on the surface of 2A70 high-strength aluminum alloy by direct laser deposition technology. The microstructure of the coating was analyzed, and the high-temperature wear resistance of the coating was studied and compared with that of the substrate. The “stirring” effect of TiC particles on the molten pool could effectively reduce the porosity defects. The 40 %TiC coating has the highest shear strength. The main phases in the coating are α-Al and TiC, and the diffusely distributed TiC particles effectively prevented the foreign matter from pressing into the coating, thus improving the wear resistance of the coating. The 20 %TiC and 40 %TiC coatings mainly occurred in abrasive wear and adhesive wear at different temperatures, while the 60 %TiC coating mainly occurred in fatigue wear with more spalling pits on the wear surface and the largest wear rate. The 40 %TiC coating shows the most excellent wear resistance.

Effect of TiC particles on ductility dip cracking susceptibility of Ni-base superalloy

Ni-base superalloy FM-52M is mainly used in welded structures of key equipment of nuclear power plants, such as pressure vessels and heat dissipation evaporators. It is prone to form coarse columnar microstructures during welding and has significant ductility dip cracking (DDC) susceptibility. This work attempted to introduce micrometre-sized TiC particles into FM-52M welds to refine the microstructure and alleviate sensitivity to DDC. A Ni–TiC coating with good dispersion and uniformity of TiC particles was first prepared on the substrate by composite electroplating. The TiC particles were then directly introduced into the molten pool during tungsten–inert gas welding. Scanning electron microscopy and electron backscatter diffraction were used to analyse the microstructure of the weld and strain-to-fracture testing was performed to evaluate its DDC sensitivity. The experimental results showed that solidification grains of the weld were obviously refined and its high-temperature mechanical properties were reinforced. The minimum critical strain for DDC increased to approximately 3.5%, and the crack morphology was small and tortuous. Compared with the original material, the microstructure and DDC resistance of the weld were improved by introducing TiC particles.

Influence of Inert Particle Additives on Properties of Nano-Microcrystalline Alloys on Based on Al–Fе–V–Si

A new trend in production of aluminum alloys used in construction in the automotive and aerospace industries is manufacture of composite materials. The structure and connection between matrix and particles are studied. This article considers the effect of TiC particles on the structure and properties of nano-microcrystalline alloys based on the Al–Fe–V–Si system. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), optical microscopy (OM), scanning probe microscopy (SPM), and Vickers microhardness measurements are used in order to study ribbon crystal lattice parameters.

Effect of TiC particles on the oxidation behavior of 2Cr13 stainless steel in a simulated marine environment at 550°C

AbstractIn this study, the oxidation behavior of 2Cr13 stainless steels with/without TiC particles was investigated in a simulated marine environment at 550°C. The results showed that TiC particles greatly accelerated the oxidation rate of 2Cr13 steel during the cyclic oxidation reaction. At the same time, the effect of acceleration was alleviated by the small size and uniform distribution of TiC particles. As galvanic corrosion in the vicinity of TiC particles occurred in 3.5% NaCl solution spray, more NaCl particles deposited on the alloy surface, especially in the area around TiC particles. At 550°C, some shell‐like oxidation products were generated on the 2Cr13 steel surface due to TiC addition, and then the porous oxidation products provided poor protective ability. Besides, the defect and stress in the oxide scale was reduced due to the small size and uniform distribution of TiC particles in 2Cr13 steel.

Effect of TiC particles on three-body abrasive wear behaviour of low alloy abrasion-resistant steel

Low alloy abrasion resistant steel is an indispensable material used in the machinery manufacturing industry. In order to further improve its wear performance without increasing its hardness, a series of low alloy wear resistant steel reinforced with TiC particles was developed. The microstructures were characterized by SEM and TEM. The three-body abrasive wear behaviour of experimental steels has been studied using dry sand rubber wheel testing machine under different applied loads, abrasive particles, and rubber wheel rotation speeds. The results showed that the microstructure of the TiC-reinforced low alloy abrasion-resistant steel consisted of a martensite matrix and nano- and micro-sized TiC particles. Although the TiC particles consumed the C element in the matrix, thus reducing the hardness and strength of the experimental steels, the wear resistance did not decrease. The wear resistance of TiC-particle-reinforced steels was proportional to the density of the TiC particles. Furthermore, the worn surface morphology indicated that the abrasive wear mechanism of TiC-reinforced experimental steels was mainly plastic deformation, fracture, and fatigue, which is different from the micro-cutting observed in traditional low alloy abrasion-resistant steel. The different wear mechanism will aid in improving the wear performance of the steels.

Effects of TiC Addition on Directionally Solidified Microstructure of Ti6Al4V

In this study, the effects of TiC particles as the heterogeneous nucleus on the microstructure of directionally solidified Ti6Al4V were investigated. Ti6Al4V powder containing 0.0, 0.3, 1.0, and 2.0 vol pct TiC particles in a Ti6Al4V sheath was melted and directionally solidified with a floating zone melting method. In this process, the temperature gradient G was approximately 12 K/mm, and the solidification rate R was 15 mm/min. The mean size of prior β grains decreased with increasing TiC addition. In samples containing TiC particles, some grains had an aspect ratio lower than 1. This indicated that TiC particles acted as the heterogeneous nucleus and generated fine and equiaxed prior β grains. Although the many TiC particles melted into molten Ti6Al4V and the excessively melted carbon from TiC particles precipitated as Ti2C, residual TiC particles acted as a heterogeneous nucleus.

Microstructure evolution during the liquid-liquid phase transformation of Al-Bi alloys under the effect of TiC particles

Solidification experiments were carried out for Al-Bi alloys with the addition of TiC. It is demonstrated that the average size of the Bi-rich minority phase particles (MPPs) shows a tendency of keeping constant, increasing, decreasing and then keeping constant again with the increase of the additive amount of TiC. The MPPs can be refined effectively with the addition of an appropriate amount of TiC. A model was developed to describe the kinetic behavior of the TiC particles in the melt and the microstructure evolution during the liquid-liquid (L-L) phase transformation of the Al-Bi alloys with the addition of TiC. The numerical results show that TiC particles may dissolve and coarsen during the heating period, and precipitate out during the cooling period of the melt. There may be two kinds of TiC particles: the one remained during holding temperature and the one precipitated during a cooling of the melt. Both of them can work as the inoculants for the nucleation of the minority phase droplets. What determines the refining efficiency is the resultant number density of the TiC particles in the melt cooled to the binodal line temperature. This research demonstrates that inoculation is an effective method for controlling the L-L phase transformation. The addition of the efficient inoculant may promote the formation of a monotectic alloy with a well dispersed microstructure.

Effect of TiC Particles on Microstructure and Properties of Al-Fe-V-Si Alloy

Heat-resistant Al-Fe-V-Si aluminum alloys enhanced by in-situ TiC particles have been prepared by spray forming process with suitable process parameters. Research results show that the microstructure of as-deposited alloy is fine and homogeneous. In-situ TiC particles prevent the unsteady phases from coming into being. On the other hand, the TiC particles increase the volume fraction of heat-resistant phases. So the mechanical properties of the enhanced alloy by in-situ TiC particles are better than that of Al-Fe-V-Si alloy without TiC particles. The hot extrusion temperature is also an important parameter to understand. Under the permission, it is better to extrude the alloy at lower temperature. The tensile strength of the alloy without TiC particles is about 435MPa at room temperature and is about 204MPa at 350°C. However, when the alloy is enhanced by in-situ TiC particles, the strength of alloy is about 482MPa at room temperature and is about 224MPa at 350°C temperature.

Multi-Walled Carbon Nanotubes Reinforced Titanium Composites via Powder Metallurgy Process

Un-bundled multi-walled carbon nanotubes (MWCNTs) were coated on titanium powder surface by using zwitterionic surfactant solution and mixing process, and their CNT/Ti composite powders were consolidated into full-dense materials by spark plasma sintering and the following hot extrusion process in solid-state. Wrought titanium powder metallurgy (PM) composites containing CNTs revealed extreme increment of yield stress and tensile strength of 85% and 50%, respectively, compared to conventional PM titanium with no reinforcement, while they had enough high ductility. The mechanical improvement was mainly due to dispersion strengthening effect of CNTs and in-situ formed TiC fine particles and a small mount of carbon solid solution into Ti matrix. In addition, the control of grain growth was promoted by TiC dispersoids during SPS, and contributed to their strengthening behavior. Furthermore, high-temperature tensile strength less than 673K of PM pure titanium materials was also obviously improved by the pinning effect of TiC particles dispersed at grain boundaries. In this paper, microstructural and mechanical properties of powder metallurgy titanium composites would be introduced in detail.

A new nucleation mechanism of primary Si by like-peritectic coupling of AlP and Al 4C 3 in near eutectic Al–Si alloy

The effect of TiC particles on the phosphorous modification efficiency in near eutectic Al–Si alloy and a new nucleating mechanism was studied in this paper. The results show that the phosphorous modification efficiency can be significantly improved and the sizes of the primary Si can be obviously refined after the addition of trace TiC particles. EPMA shows there is a coupling of AlP and Al 4C 3 particles in the center of primary Si, and a new nucleation mechanism of primary Si by like-peritectic coupling of AlP and Al 4C 3 was presented. The formation mechanism of like-peritectic coupling of the particles was also discussed.

Fabrication and mechanical properties of TiC/TiAl composites

TiC/TiAl composites with different TiC content were fabricated by rapid heating technique of spark plasma sintering (SPS). The effect of TiC particles on microstructure and mechanical properties of TiAl matrix was investigated. The results indicate that grain sizes of TiAl matrix decrease and mechanical properties are improved because of the addition of TiC particles. The composites display a 26.8% increase in bending strength when 10wt% TiC is added and 43.8% improvement in fracture toughness when 5wt% TiC is added compared to values of TiC-free materials. Grain-refinement and dispersion-strengthening were the main strengthening mechanism. The improvement of fracture toughness was due to the deflexion of TiC particles to the crack.

On the effect of TiC particles on the tensile properties and on the intrinsic two way effect of NiTi shape memory alloys produced by powder metallurgy

The present study investigates the tensile properties of a nickel titanium (NiTi) shape memory alloy (SMA) produced by powder metallurgy (PM) with and without TiC-particles. It discusses the effect of the addition of particles on the mechanical behavior in tension and studies the intrinsic two way effect (ε2W) after thermomechanical training. Special emphasis is placed on the stability of ε2W after subsequent thermal cycling. The results are discussed on the basis of an analysis of the thermomechanical data and microstructural results. The present study shows that the PM route can produce NiTi SMAs with tensile properties which match those of materials produced by classical ingot metallurgy. Adding TiC particles to NiTi SMAs alters the phase transition temperatures (PTTs) and affects the SMA performance. Adding more than ten volume percent TiC particles results in early and brittle rupture during tensile loading.

Niti and NiTi-TiC composites: Part II. compressive mechanical properties

The deformation behavior under uniaxial compression of NiTi containing 0, 10, and 20 vol pct TiC participates is investigated both below and above the matrix martensitic transformation temperature: (1) at room temperature, where the martensitic matrix deforms plastically by slip and/or twinning; and (2) at elevated temperature, where plastic deformation of the austenitic matrix takes place by slip and/or formation of stress-induced martensite. The effect of TiC particles on the stress-strain curves of the composites depends upon which of these deformation mechanisms is dominant. First, in the low-strain elastic region, the mismatch between the stiff, elastic particles and the elastic-plastic matrix is relaxed in the composites: (1) by twinning of the martensitic matrix, resulting in a macroscopic twinning yield stress and apparent elastic modulus lower than those predicted by the Eshelby elastic load-transfer theory; and (2) by dislocation slip of the austenitic matrix, thus increasing the transformation yield stress, as compared to a simple load-transfer prediction, because the austenite phase is stabilized by dislocations. Second, in the moderate-strain plastic region where nonslip deformation mechanisms are dominant, mismatch dislocations stabilize the matrix for all samples, thus (1) reducing the extent of twinning in the martensitic samples or (2) reducing the formation of stressinduced martensite in the austenitic samples. This leads to a strengthening of the composites, similar to the strain-hardening effect observed in metal matrix composites deforming solely by slip. Third, in the high-strain region controlled by dislocation slip, weakening of the NiTi composites results, because the matrix contains (1) untwinned martensite or (2) retained austenite, which exhibit lower slip yield stress than twinned or stress-induced martensite, respectively.