Fe TiC Research Articles

Preparation of iron-based composites reinforced with submicron/nano-sized TiC ceramic particles by in-situ reaction in melts and one-step integrated hot pressing densification

The iron matrix composites strengthened with submicron/nano-sized TiC particles dopping with different alloying elements (Mo, Ni) were prepared by melt-in-situ reaction and one-step integrated hot compaction. The results indicate that the incorporation of Mo and Ni through alloying treatment can refine ceramic particles, and thus lead to a significant improvement in the uniformity of the microstructure. The mismatch between the TiC and α-Fe is significantly reduced and the interface stability is enhanced. The yield strength of 1904 MPa and maximum compressive strength of 2605 MPa of TiC/Fe composite with the addition of 4 wt.% Mo are 28.3 % and 23.9 % higher than those without alloying elements, respectively. The yield strength of 2032 MPa and maximum compressive strength of 2815 MPa of TiC/Fe composite with the addition of 2 wt.% Ni are 36.9 % and 33.9 % higher than those without alloying elements, respectively. First-principles calculation results indicate that Mo atoms tend to accumulate at the interface, while Ni atoms can easily substitute Fe atoms, resulting in the formation of a FeNi solid solution. The primary strengthening mechanisms of TiC/Fe composites dopping Mo are the refinement strengthening of ceramic particles. The interface bond between Fe matrix and TiC particles is also strengthened. The addition of Ni primarily leads to solid solution strengthening and grain refinement. This TiC particle manipulating strategy within Fe melt can effectively optimize the corresponding interfacial bonding, lead to comprehensive improvement in property, and finally realize the expanding application at specific wear locations.

Material removal mechanism of TiCp/Fe composite by multi-diamond-abrasive-grinding considering the random distribution characteristics of particles

The TiC ceramics reinforced Fe matrix composite (TiCp/Fe) exhibits exceptional properties, including high hardness, strength, wear, and heat resistance. This study focuses on investigating the material removal mechanism to achieve high-quality and low-damage surfaces. A three-dimensional particle random distribution algorithm is proposed based on the random distribution characteristics of TiC particles. Furthermore, a multi-diamond-abrasive grinding finite element model is established using the Rayleigh probability distribution model to account for the randomness of undeformed chip thickness during the grinding process. This study combines experimental and simulation analyses to investigate the variations in grinding forces, stress field distributions, and surface and subsurface quality. The results reveal that the material removal process can be categorized into five stages: ploughing of the Fe matrix and TiC particle, TiC particle crack initiation, TiC particle crack extension, and TiC particle fracture. Moreover, the process of removing TiC particles can be further grouped into ductile removal, ductile-brittle removal, and brittle removal, depending on the undeformed chip thickness. This study improves the comprehension of the mechanism of TiCp/Fe composite material and establishes a significant practical guidance for the diamond grinding processing of metal matrix composites.

Effects of rare earth oxides on wear resistance and corrosion resistance of 316L/TiC composite coating by laser cladding

In this paper, 316L/TiC composite coatings with different kinds of REOs (Y2O3, La2O3, CeO2, PrO2, Nd2O3) at identical contents (2%) were prepared on S355 marine steel using the laser cladding technology. The surface morphology, phase composition, microhardness, coefficient of friction curve (COF), Tafel curve and electrochemical impedance spectroscopy (EIS) impedance of the test specimens were studied with such instruments as scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffractometer, Vickers microhardness tester, friction and wear tester, and multi-channel electrochemical workstation. The results show that the coating with REO added owns increased thickness and is uniform and dense without such defects as crack, and hole. The microstructure evolution mechanism of the coating from the bottom up is as follows: Cellular crystal, planar crystal → columnar crystal → equiaxed crystal. The phase composition of the coating with REO added remains unchanged, and is still Ni–Cr–Fe austenite phase and TiC phase. Further comparison shows that the coating with Nd2O3 added owns improved hardness, with a mean hardness of 3 times that of the substrate, and has a COF decreasing to 0.69, with wear loss becoming small. The coating with Nd2O3 added has the largest Ecorr, the smallest Icorr, large Z value and phase angle, the greatest Rct, and an nct value of 1, indicating that the coating has dense passivation film and small corrosion tendency, with low corrosion rate. Therefore, this study provides reference experimental and theoretical bases for application of 316L/TiC composite coating with Nd2O3 added at 2% in surface strengthening and repair of steel for marine engineering equipment.

Refractories for the processing of Fe–TiC alloy

In order to select the appropriate crucible material for Fe–TiC composite alloy processing, Al2O3, CaZrO3, and MgO-stabilized ZrO2 ceramic substrates were tested for interaction with a liquid Fe–TiC alloy at 1650 °C. The sessile drop method under protective gas was applied to conduct the experiment. The measured contact angle of Fe–TiC alloy followed the tendency of MgO-stabilized ZrO2˃CaZrO3˃Al2O3. After investigations, the Al2O3 substrate was strongly corroded by the liquid Fe–TiC alloy. The CaZrO3 substrate showed a smooth and non-corroded interface after the interaction. Reactions products TiOx and MgTiOx were detected between alloy and Mg–ZrO2 substrate. Obtained results were discussed under consideration of SEM/EDX analysis, which was conducted on the cross-section samples of metal/ceramic compound and on the top surface of the solidified Fe–TiC alloy; and of thermodynamic simulations of the Fe–TiC alloy interaction with the investigated substrates.

The corrosion behavior of Ni–Fe and Ni–Fe–TiC nanoparticles deposited using pulse electrodeposition on low-carbon steel

The corrosion behavior of Ni–Fe and Ni–Fe–TiC nanoparticles deposited using pulse electrodeposition on low-carbon steel

Microstructure, preparation and properties of TiC-Fe/ FeCoCrNiMn cermet with a core-rim structure

High entropy alloys (HEAs) have become an ideal material for preparing cermets because of their properties, such as high hardness, good wear resistance, and excellent heat resistance. In this paper, TiC-Fe/HEA cermet was prepared by vacuum sintering with Fe powder, HEA(FeCoCrNiMn) powder, and TiC particles. The effect of HEA content on the microstructure and properties of TiC-Fe cermet was studied, and the preparation process of cermet was optimized. The results show that the cermet grains without HEA are angular or polygonal, while the cermet grains with HEA are round and oval. With the addition of HEA, the grain size decreased at first and then increased. In addition, with increasing HEA content, the hardness, transverse rupture strength, and fracture toughness of cermet first increased and then decreased, while the relative density decreased slightly. HEA had the best properties among these HEA cermets at 10 wt%, and its hardness, transverse rupture strength (TRS), and fracture toughness (KIC) reached 1530 HV30, 980 MPa, and 10.57 MPa•m1/2 respectively. Compared with cermet without HEA, these values were increased by 36%, 20%, and 11%, respectively.

Manufacturing Fe–TiC metal matrix composite by Electron Beam Powder Bed Fusion from pre-alloyed gas atomized powder

Fe–TiC metal matrix composite (MMC) material is fabricated by EB-PBF (Electron Beam Powder Bed Fusion) additive manufacturing technique. Herewith, gas atomized model alloy powder containing in-situ formed reinforcement phase is utilized. Powder properties (i.e., particle size distribution, morphology, flowability, tap, and apparent density) are discussed in relation to composite powder applicability for EB-PBF. As a result, samples with over 99% density were fabricated. Cross-section samples investigated via SEM (scanning electron microscopy) and EBSD (electron back-scattered diffraction analysis) reveal homogeneously distributed submicron TiC reinforcements of two morphologies – blocky TiC precipitates and fine needle-shaped ones. Fabricated composite demonstrates enhanced tensile strength of 537 MPa, while preserving the sufficient level of ductility (35.0%), which correlates with the low hardness of 153.9 HV10. Additionally, heat treatment of as-built samples is investigated by implementing differential scanning calorimetry (DSC), dilatometry analysis, and austenitization-water-quenching techniques. Applied heat treatment induces a significant grain refinement, which increases the hardness of treated samples up to 246.3 HV10 by water quenching, while TiC precipitates undergo minor changes in morphology and size. Fabricated MMC material demonstrates the successful application of the gas atomized powder with an in-situ formed carbide reinforcement phase for additive manufacturing.

БЕЗВОЛЬФРАМОВЫЕ ТВЕРДЫЕ СПЛАВЫ: МЕТОДЫ ПОЛУЧЕНИЯ, СТРУКТУРА И СВОЙСТВА (обзор)

In this paper provides an overview of scientific and technical literature and developments in the field of tungsten-free hard alloys or cermet as promising materials of a new generation metalworking tools. Methods of obtaining sintered hard alloys, their structure and basic operational properties are considered The main directions of improving the properties of hard alloys are given. The results of experimental work on the production of cermet by high-speed quenching of the melt are presented. The obtained fast-quenched materials of the Fe–TiC–TiB2 system demonstrate physical and mechanical properties at the level of sintered hard alloys, but at the same time it contain 2–3 times less of the carbide phase.

Manufacturing Fe–TiC Composite Powder via Inert Gas Atomization by Forming Reinforcement Phase In Situ

Fe–TiC metal matrix composite powder is manufactured applying vacuum inert gas atomization technique. The TiC reinforcement phase forms in situ within spraying of the Fe‐based molten metal preliminary alloyed with 1 wt% [C] and 4 wt% [Ti]. Alloying strategy, homogenization time, and spraying temperature are varied for three conducted atomization experiments in this study. Medium particle size (d50) lies in a range of 41–55 μm for obtained spherical powders. Scanning electron microscopy (SEM) analysis and Energy‐dispersive X‐ray spectroscopy (EDX) mapping of powder cross‐section samples reveal well‐dispersed submicron TiC precipitates of two different morphologies—primary‐blocky and eutectic‐plate‐shape carbides. The amount of precipitates and their morphology depend on the particle size. Namely, coarser powder particles tend to have more primary carbides that are presumably formed already in liquid droplets. Meanwhile, TiC precipitation in finer particles up to ≈25 μm is completely suppressed due to an extremely high cooling rate. Difficulties of the Fe–Ti–C melt atomization (e.g., formation of a semiliquid slag layer, loss of TiC forming elements, the presence of large precipitates in a powder) are discussed considering the thermodynamic analysis of this system and Fe–TiC remelting experiments conducted on a hot stage microscope.

On Wear Resistance of Steel-Containing Composites under Extreme Friction Conditions

The interrelation between the mechanisms of surface layer deterioration of powder composites and the elemental compositions of their primary structures under extreme friction conditions was studied. Extreme conditions were set by sliding under high pressure (>100 MPa) with boundary lubrication or by dry sliding under high-density electric current (>100 A/cm2). This resulted in plastic deformation of the surface layers and their deterioration due to low-cycle fatigue. High wear resistance of materials in such conditions should be achieved due to satisfactory stress relaxation in the surface layers. It was suggested that stresses should be relaxed due to local plastic deformation in the vicinity of the emerging stress concentrators. The ease of plastic deformation (and ease of relaxation) should be ensured by reduced doping of the structural components of composites, i.e., due to the lack of solid solutions. It was shown that the composites having Cu–steel (alloy)–TiC compositions obtained by self-propagating high-temperature synthesis with simultaneous pressing of the burning charge demonstrated strong adhesion at the sliding contact and showed low wear resistance under high boundary friction pressures. The absence of solid solutions in the primary structure of the Cu–Fe–TiC composite corresponded to high wear resistance due to the absence of adhesion at the contact and easy stress relaxation. Composites of Cu–steel-graphite compounds made by sintering in vacuum showed strong adhesion at a dry sliding electrical contact and low wear resistance due to the high content of alloying elements. It was noted that the absence of solutions in the Cu–Fe–graphite composite prevented adhesion at the contact and resulted in high wear resistance. In addition, stresses in the surface layer were also relaxed by the formation of FeO in the contact space during sliding with the current collector. Composites containing solid solutions were incapable of forming FeO on the sliding surface. This was an additional reason for the low wear resistance. It was noted that solid solutions caused a decrease in thermal conductivity of the surface layer, leading to increase in temperature gradients on the sliding surface and corresponding acceleration of friction zone deterioration.

Microstructure and wear properties of Fe–TiC composite coatings produced by submerged arc cladding process using ferroalloy powder mixtures

Fe-TiC composite coatings were produced on the surface of plain carbon steel by submerged arc cladding process. Mixtures of cast iron chips and ferrotitanium powder with different weight ratio between 1 and 6 were used as the alloying element sources. Cladding was performed by carbon‑manganese steel wire. Results showed that increase in the cast iron to ferrotitanium (CTF) weight ratio from 1 to 6 decreased the Ti wt% from 3.93 to 0.96 and increased the carbon concentration from 0.26 to 0.51 wt%. Titanium carbide reinforcing particles were detected in the microstructures of all coatings. Meanwhile, their size and volume fraction, as well as the microstructure of the matrix strongly was depending on the CTF weight ratio. The highest mean hardness value of 960 HV was obtained for the cladding produced by the CTF weight ratio of 6 with the TiC reinforced martensitic microstructure. Pin on disk wear test results showed that the hardest coating had the best wear resistance with the plowing and cutting wear mechanisms.

Effect of interfacial compounds on mechanical properties of titanium–steel vacuum roll-cladding plates

ABSTRACTThe titanium–steel clad plates were prepared by vacuum roll cladding. Ti–Fe compounds and TiC were observed at different cooling rates after rolling. Optical microscopy, electron microprobe analyser, X-ray diffraction and shear test studies were carried out to study the effect of Ti–Fe compounds and TiC on the ultimate microstructure and mechanical properties of titanium–steel clad plates. At a cooling rate of 6.2°C/min, TiC and Ti–Fe compounds seriously impacted the mechanical properties of the clad plate. At a cooling rate of 1.8°C/min, the thickness of the TiC layer was optimal much that the maximum shear strength of 296 MPa was obtained. At a cooling rate of 0.6°C/min, the thickness of the TiC layer was relatively thick, which affected the mechanical properties of clad plates.

Thermal monitoring of microstructure and carbide morphology in direct metal deposition of Fe-Ti-C metal matrix composites

Abstract In this paper, real-time cooling rate of Fe-Ti-C Metal Matrix Composites (MMCs) made by Direct Metal Deposition (DMD) are measured to monitor microstructure and carbide morphology. This research proves that carbide morphology developed by DMD of Fe–TiC composite coating on AISI 1020 carbon steel is highly affected by cooling rate and pre-heat. For this purpose, the DMD process is monitored by a thermal camera to obtain real-time values of the cooling rate resulted from a range of selected scan speeds. Two approaches are studied for the single-track depositions: (a) single speed and (b) dual speeds in which the scan speed changes during the deposition. The dual speed generates different preheat values during deposition and thus deviates the cooling rate. Consequently, the effect of cooling rate and preheat temperature are studied on carbide morphologies. Results show that scan speed plays the main role in the formation and distribution of TiC particles in the deposited layer by affecting the cooling rate and dilution (melt pool composition). Based on this research, it is possible to control the cooling rate in order to achieve specific carbide morphologies in the deposited layer. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are used to characterize the deposited layers' microstructure.

IN SITU DEPOSITION OF Fe-TiC NANOCOMPOSITE ON STEEL BY LASER CLADDING

The possibility of deposition of Fe–TiC nanocomposite on the surface of carbon steel substrate with the laser coating method had been investigated. Mechanical milling was used for the preparation of raw materials. The mixture of milled powders was used as a coating material on the substrate steel surface and a CO2 laser was used in continuous mode for coating. Microstructural studies were performed by scanning electron microscopy. Determinations of produced phases, crystallite size and mean strain have been done by X-ray diffraction. The hardness and wear resistance of coated samples were measured. The results showed that the in situ formation of Fe–TiC nanocomposite coating using laser method is possible. This coating has been successfully used to improve the hardness and wear resistance of the substrate so that the hardness increased by about six times. Coated iron and titanium carbide crystallite sizes were in the nanometer scale.

In Situ Synthesis of Fe–TiC Nanocomposite Coating on CK45 Steel From Ilmenite Concentrate by Plasma-Spray Method

These days wear-resistant coatings including Fe–TiC composites because of their properties such as high melting point, hardness, and wear resistance are used in different fields such as aerospace, transport, cutting, and abrasive. In situ synthesis of Fe–TiC nanocomposite as a wear-resistant coating by the plasma-spray process is the purpose of this study. Ilmenite concentrate and carbon black were used as raw materials. Three kinds of powders with different conditions were prepared and sprayed on CK45 steel substrates in constant conditions. Microstructure, phase identification, wear resistance, and hardness of coated samples were determined. The results showed that activated sample was synthesized during the plasma spray, but in situ synthesize did not happen for inactive sample which was sprayed by plasma spray. Also, wear resistance and hardness tests showed by synthesis of Fe–TiC composite in coated samples, wear resistance, and hardness were increased.

Fabrication of Fe–TiC–Al2O3 composites on the surface of steel using a TiO2–Al–C–Fe combustion reaction induced by gas tungsten arc cladding

The aim of the present study was to fabricate Fe–TiC–Al2O3 composites on the surface of medium carbon steel. For this purpose, TiO2–3C and 3TiO2–4Al–3C–xFe (0 ≤ x ≤ 4.6 by mole) mixtures were pre-placed on the surface of a medium carbon steel plate. The mixtures and substrate were then melted using a gas tungsten arc cladding process. The results show that the martensite forms in the layer produced by the TiO2–3C mixture. However, ferrite–Fe3C–TiC phases are the main phases in the microstructure of the clad layer produced by the 3TiO2–4Al–3C mixture. The addition of Fe to the TiO2–4Al–3C reactants with the content from 0 to 20wt% increases the volume fraction of particles, and a composite containing approximately 9vol% TiC and Al2O3 particles forms. This composite substantially improves the substrate hardness. The mechanism by which Fe particles enhance the TiC + Al2O3 volume fraction in the composite is determined.

Microstructure and wear resistance of in-situ TiC–Al2O3 particles reinforced Fe-based coatings produced by gas tungsten arc cladding

ABSTRACT The present research aimed to fabricate Fe–TiC–Al 2 O 3 coatings on the surface of 1045 steel by gas tungsten arc cladding process. 3TiO 2 –4Al–(3 + x)C– y Fe (x = 1.5 and 3, y = 0 and 1.71) mixtures were used as cladding precursors. The mixtures and the substrate were then melted using a gas tungsten arc cladding process. Results showed that a composite containing 20 vol.% reinforcing phases was fabricated using 3TiO 2 –4Al–4.5C–1.71Fe precursor. The composite coatings formed by a four-step mechanism including, the formation of TiC into the Fe particles in front of the molten pool, the entrance of the Fe particles to the weld pool, the dissolution of TiC into the melt and finally, re-precipitation of TiC during solidification separately or on Al 2 O 3 particles. Also, incomplete dissolution of some TiC formed TiC–Al 2 O 3 colonies in the structure of the coatings. The hardness of the coatings increased up to the maximum of 830 HV which improved the abrasive wear resistance of the substrate.

Controlling conditions for synthesis of iron-titanium carbide using two different titanium precursors

Preparation of Fe–TiC composite from mixtures of carbon black and two different titanium bearing minerals (black sand ilmenite and natural rutile) was studied. Milled (mechanically activated) and unmilled carbon containing mixtures were prepared and then heated at temperatures 1200°C and 1300°C for 3h under an inert atmosphere. The reaction progress, as well as reaction products, was evaluated using thermogravimetric analysis (TGA-DTA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDX). The feasibility of producing Fe–TiC composites from titanium bearing materials mixed with carbon black was proved. Fe–TiC could be produced by carbothermic reduction of mechanically activated black sand ilmenite containing mixtures milled for 50h and heated up to 1200°C. On the other hand, 60h milling followed by heating up to 1300°C was needed in case of natural rutile containing mixture. The morphology of the Fe–TiC produced from black sand ilmenite showed a homogeneous distribution of Fe and TiC enriched areas, while the Fe–TiC produced from natural rutile showed intense distribution of TiC phase with traces of iron and lower titanium oxide.

Mechanosynthesis of Nanocomposites Based on Fe-TiC and Fe-TiN in Hydrocarbon Medium

In this paper the nanocomposites based on Fe TiC and Fe TiN which were produced by mechanosynthesis of the mixture of Fe or Fe N (82 at.%) and Ti (18 at.%) in toluene for 16 h and subsequent compaction have been studied. The structural-phase composition and morphology of the mechanosynthesized powders were studied by X-ray di raction analysis, the Mossbauer spectroscopy and electron microscopy. It has been shown that powders of the following composition: a solid solution based on Fe, TiC or TiN, a phase on the basis of Fe3C are formed by mechanosynthesis. The measurements of microhardness and corrosion resistance of the produced compacts were carried out as well.

Effect of cooling rate and laser process parameters on additive manufactured Fe–Ti–C metal matrix composites microstructure and carbide morphology

In this paper, laser additive manufacturing (LAM) of Fe–TiC composite coating on AISI 1030 carbon steel is investigated using a numerical and experimental method. In order to have a desired result using LAM, it is crucial to understand the effects of the process parameters’ values on the TiC morphology and microstructure. For this purpose, the LAM process is numerically simulated in order to calculate cooling rate and peak temperature. Experimental data and numerical results are in good agreement in terms of the phase development. Results show that cooling rate plays a crucial role in phase transformation in the clad, however, final microstructure strongly depends on the cooling rate and powder's chemical composition. Two main carbide morphologies (i.e. dendritic and particulate) are studied and relevant cooling rates are detected. Based on this paper and developed map, it is possible to control the cooling rate in order to achieve specific carbide morphologies in the clad. In this study, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are used to characterize clads’ microstructure.