Ti3SiC2 Powders Research Articles

Fabrication of SiCf/Ti3SiC2 by the electrophoresis of highly dispersed Ti3SiC2 powder

This paper reports the processing details and important phenomena occurred during the fabrication of a SiC fiber-reinforced Ti3SiC2 matrix composite (SiCf/Ti3SiC2). Because both SiC and Ti3SiC2 are microwave absorbing materials, the fabrication of SiCf/Ti3SiC2 deserves extensive study, where an improved mechanical property is expected due to the SiC fibers incorporated in the Ti3SiC2 matrix. To fabricate the composite, a highly dispersed Ti3SiC2 slurry was prepared by considering both steric and electrostatic dispersion mechanisms after adding different types of dispersants and polymeric processing additives. Electrophoresis was performed under a DC electric field to infiltrate the Ti3SiC2 particles into the voids of Tyranno™-SA grade 3 woven fabric, followed by hot pressing at 1350 °C under 20 MPa. High energy milling of the starting material accelerated the decomposition of Ti3SiC2 during sintering due to mechano-chemical activation. By adopting mild ball milling, however, SiCf/Ti3SiC2 with a density ≥90% and a flexural strength ≥100 MPa could be fabricated, retaining the most of Ti3SiC2 matrix phase.

Microstructure and Tribological Behavior of In Situ TiC-Ni(Si,Ti) Composites Elaborated from Ni and Ti3SiC2 Powders

Herein, we study the effect of Ti3SiC2 on the microstructures and tribological properties of an in situ TiC reinforced Ni(Si, Ti) composites elaborated from Ni and Ti3SiC2 MAX phase powders against steel (100Cr6). Pressureless sintering at 1080 °C for 4 h of Ni and Ti3SiC2 powders was used to elaborate these composites with 10, 20 and 30 wt.% of Ti3SiC2. The microstructures of the composites were investigated by scanning electron microscopy (SEM), x-rays diffraction and Raman spectroscopy. Standard ball-on-disk friction wear tests under different applied loads were conducted on the composites surfaces at room temperature. For the three elaborated composites, Ti3SiC2 was totally decomposed and transformed to TiC phase, while the released Si and Ti atoms from Ti3SiC2 diffused into Ni matrix forming Ni(Si, Ti) solid solution. As compared with reference (Ni) sinter, the addition of 20 wt.% Ti3SiC2 in the Ni matrix improved the hardness by ~ 250%. The addition of Ti3SiC2 particles also had a beneficial effect on the tribological performance of these composites against steel. The worn surfaces of the elaborated composites under all applied loads are characterized by the presence of a lubricious Fe3O4-αFe2O3 tribofilms. The effect of chemical compositions and different applied loads on the wear mechanisms of the three elaborated composites is discussed.

Study of the synthesis of MAX phase Ti3SiC2 powders by pressureless sintering

MAX phases exhibit excellent combination of ceramic and metallic-like properties. In this work, MAX phase Ti3SiC2 powder was synthesized starting-off with different combinations of elemental powders and carbides. The powders used were Ti, Si, C, SiC and TiC in different combinations, molar ratios and powder size. Powders were heat treated on a vacuum furnace for different times and temperatures for in situ production of the Ti3SiC2 MAX phase. High purity synthesized samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to identify and quantify the different phase constituents present. The main phase constituents in the powders produced were Ti3SiC2 and TiSi2. Up to 94% of Ti3SiC2 MAX phase was obtained using Ti:SiC:C as starting powders in a molar ratio of 3:1.5:0.5. Different phase constitution was observed on the surface and the centre of the samples. An optimal starting powder composition, molar ratio, heat treatment temperature and time is proposed for the formation of high purity Ti3SiC2 MAX phase. Selected mixture was studied thermodynamically and a reaction mechanism of formation of the MAX phase is proposed.

Development of SrFe12O19/Ti3SiC2 Composites for Enhanced Microwave Absorption

Microwave absorbing composites containing strontium hexaferrite and titanium silicon carbide, SrFe12O19/Ti3SiC2 powder, were synthesized by mixing in different weight ratios. The strontium hexaferrite (SrFe12O19) particles were synthesized using low-temperature combustion. The ‘as synthesized’ strontium hexaferrite powder is observed to have low coercivity (255.09 G) and high saturation magnetization (45.1 emu/g). The titanium silicon carbide (Ti3SiC2) powder was synthesized by heat treatment of the precursors (Ti/Si/TiC) at 1100°C under argon atmosphere. A microwave absorbing composite is fabricated by mixing in a high-energy ball mill followed by heating of SrFe12O19 and Ti3SiC2 powders at 200°C. The maximum reflection loss of − 39.67 dB is observed at 9.46 GHz for the composite casted into pellets containing 20% Ti3SiC2 and 80% SrFe12O19 with 2-mm thickness. The bandwidth for less than − 10 dB loss is observed to be 2.77 GHz (66% of the total band). The developed magneto-dielectric composition confirmed its candidacy as a potential microwave absorbing material.

SiC- and Ti3SiC2-Based Ceramics Synthesis by Spark Plasma Sintering of Preceramic Paper

This paper is devoted to proposing a new approach to the synthesis of SiC- and Ti3SiC2-based ceramics by using of preceramic paper as a feedstock. A preceramic paper with SiC and Ti3SiC2 powder fillers were sintered by spark plasma sintering (SPS) method for holding time 10 minutes under pressure 20-100 MPa. The temperature for the sintering of SiC- and Ti3SiC2-filled paper was 2073-2373 K and 1373-1473 K respectively. The influence of sintering parameters on the materials microstructure was analyzed by scanning electron microscopy. It was revealed that with an increase in pressure from 20 to 100 MPa, the microstructure of the materials becomes denser. It agrees with the results of measuring the density of the sintering materials by the hydrostatic weighting. The determination of Young`s modulus by the acoustic method demonstrates that with the increase of the applied pressure during SPS, Young’s modulus of the synthesized SiC- and Ti3SiC2-ceramics increase.

Electromagnetic and microwave absorption properties of Ti3SiC2 powders decorated with Ag particles

Herein, we synthesized Ti3SiC2/Ag composite powders by electroless silver plating. The phase composition and morphology of the powders were characterized. It verified that Ag particles were attached on the surface of Ti3SiC2 powders. By measuring the complex permittivity and calculating the reflection loss, we found the dielectric constant of Ti3SiC2/Ag rises with the increasing Ag content. As the weight ratio of Ag increases from 0 to 30 wt%, the real part raises from 7.1 to 13.7 while the imaginary part enhances from 1.0 to 3.6. For the mixture containing Ti3SiC2-30 wt%Ag powders with a thickness of 2.0 mm, the reflection loss is the minimum and the RL value is −24 dB at 10.9 GHz. In addition, the minimum value of RL continuously moves to lower frequency region as the thickness increases. So we can adjust the microwave absorption performance of Ti3SiC2/Ag composite powders by changing the thickness and Ag content.

INFLUENCE OF STRUCTURAL-PHASE CONDITION ON THE MECHANICAL-TRI BOLOGICAL PROPERTIES OF Ti3SiC2 COATINGS OBTAINED BY THE DETONATION METHOD

The article provides the results of the research of the structure and properties of powder coatings based on titanium carbosilicide Ti3SiC2 obtained by detonation spraying on the surface of tool steel U9/У9 (equivalent to N9). Micro-indentation methods and abrasive wear tests for mechanical and tribological properties of Ti3SiC2 based coatings were conducted. The microstructure of the coating has a layered structure. The border between the coating and the base has a characteristic crinkled appearance. It was determined that the phase composition of the coatings changes during detonation spraying is a result of the decomposition of Ti3SiC2 powder into titanium carbide and titanium carbosilicide (secondary phases). Selected consolidation conditions ensure the formation of a Ti3SiC2/TiC composite material. The influence of the second phase content (TiC, TiO2) on the properties of coatings was studied. Studies of the microhardness of samples with coatings showed that, in the entire range of annealing temperatures, the microhardness of the Ti3SiC2/TiC composite material increases compared to the coating before annealing. It was found that the maximum microhardness of the Ti3SiC2/TiC composite material after annealing at a temperature of 800 ○C is explained by an increase in the content of the Ti3SiC2 phase. It was established that, during detonation spraying of Ti3SiC2 powders, a coating with a higher microhardness and wear resistance is formed.

Enhanced microwave absorption properties of carbonyl iron/resin composites incorporated with Ti3SiC2 particles

Hybrid Ti3SiC2 and carbonyl iron powders were composited with epoxy and polyamide resin to fabricate thin thickness and wide bandwidth microwave absorption composites. The influences of Ti3SiC2 content and particle size on the complex permittivity, complex permeability and microwave absorption properties were investigated systematically in the frequency range of 8.2–12.4 GHz. It was found that the real and imaginary parts of complex permittivity were improved obviously by increasing Ti3SiC2 content or decreasing Ti3SiC2 particle size, which are ascribed to the enhanced interfacial polarization and conductance loss. By calculating the reflection loss, the composite with 7 vol% Ti3SiC2 content and < 30 μm Ti3SiC2 particle size exhibited a wide effective absorption bandwidth of 3.6 GHz in 8.8–12.4 GHz when the thickness is 1.2 mm.

Synthesis of Ti3SiC2 MAX phase powder by a molten salt shielded synthesis (MS3) method in air

Titanium silicon carbide (Ti3SiC2) powder was synthesized by molten salt shielded synthesis route of elemental reactants. Potassium bromide (KBr) was used for gas-tight encapsulation of the consolidated reaction mixture for further high temperature processing. The synthesis of Ti3SiC2 powder was carried out in air, the salt cladding and molten salt pool provided for the protection of the material against oxidation both at low and high temperature. The process yielded free flowing Ti3SiC2 powders without the need of a milling step. Al addition to the reaction mixture resulted in a high purity (96 wt. %) of Ti3SiC2 at a synthesis temperature of 1250 °C. The synthesized micro-metric Ti3SiC2 can be milled to nano-metric powders.

Enhanced Electromagnetic and Microwave Absorption Properties of Hybrid Ti3SiC2/BaFe12O19 Powders

In this work, Ti3SiC2 powders were composited with BaFe12O19 to improve electromagnetic and microwave absorption properties. The hybrid Ti3SiC2/BaFe12O19 powders were prepared in two different ways: mechanical mixing and auto-combustion. The electromagnetic and microwave absorption properties of the powders were investigated in the frequency range of 8.2–12.4 gigahertz (GHz). For the hybrid Ti3SiC2/BaFe12O19 powders, the complex permittivity was higher while the complex permeability was lower than individual BaFe12O19 powders. In addition, the hybrid powders prepared by auto-combustion had higher complex permittivity and permeability than the mechanical mixing powders. The most favorable absorption performance was obtained for the sample with a thickness of 2.4 mm. The reflection loss value below − 5 decibels (dB) was in the frequency range of 9.3–12.4 GHz, with a minimum reflection loss value of − 14.6 dB at 10.9 GHz.

Infrared Transparency and Conductivity of Amorphous Ternary Ceramic Thin Films

In this paper, using polycrystalline Ti3SiC2 powder as target, for the first time, amorphous ternary ceramic (a-TSC) thin films are successfully fabricated on quartz and glass substrates at room temperature by direct-current (DC) sputtering. The microstructural and optoelectronic properties of the a-TSC thin films are investigated by means of XRD, Raman, EDS, four-point probe system and Vis-NIR spectrometer, respectively. It is found that despite of amorphous structure and having not so good conductivity compared with Ti3SiC2, the a-TSC thin films still have enough conductivity. Furthermore, compared with ITO, FTO and AZO thin films, the transmittance of a-TSC thin films is much higher in infrared region regardless of the film thickness. It is suggested for a-TSC thin films that the film thickness should be controlled less than 150nm in order to obtain a higher transparency with an appropriate conductivity. It is believed that a-TSC thin film will find its way to be applied in optoelectronic devices in the near future.

Microstructure and properties of Ag–Ti3SiC2 contact materials prepared by pressureless sintering

Ti3SiC2-reinforced Ag-matrix composites are expected to serve as electrical contacts. In this study, the wettability of Ag on a Ti3SiC2 substrate was measured by the sessile drop method. The Ag–Ti3SiC2 composites were prepared from Ag and Ti3SiC2 powder mixtures by pressureless sintering. The effects of compacting pressure (100–800 MPa), sintering temperature (850–950°C), and soaking time (0.5–2 h) on the microstructure and properties of the Ag–Ti3SiC2 composites were investigated. The experimental results indicated that Ti3SiC2 particulates were uniformly distributed in the Ag matrix, without reactions at the interfaces between the two phases. The prepared Ag–10wt%Ti3SiC2 had a relative density of 95% and an electrical resistivity of 2.76 × 10-3 mΩ·cm when compacted at 800 MPa and sintered at 950°C for 1 h. The incorporation of Ti3SiC2 into Ag was found to improve its hardness without substantially compromising its electrical conductivity; this behavior was attributed to the combination of ceramic and metallic properties of the Ti3SiC2 reinforcement, suggesting its potential application in electrical contacts.

Laser initiated Ti3SiC2 powder and coating synthesis

In the work the SHS synthesis of MAX phases from Ti-Si-C system were carried and initiated with use of 30 W laser beam with 40 µm spot. That kind of initiation allows locally and rapidly start the SHS synthesis and avoid the contamination coming from heating wire present during conventional method. The reaction was monitored by high-accuracy radiation pyrometer and high quality optical camera. The recorded data, together with reaction bed thermal conductivity measurements allowed to correlate to obtained powders composition and reaction speed. The reaction bed morphology was investigated by scanning electron microscopy with element distribution (EDS). The second part of the paper concerns laser reactive deposition of SHS in-situ synthetized MAX phases layer on silicon carbide substrate. The paths of deposited layer were formed under argon overpressure of 2 bar using 120 W of laser power.

Electrosynthesis of Two-Dimensional TiC and C Materials from Ti3SiC2 in Molten Salt

The two-dimensional (2-D) multilayer structured TiC and carbide-derived carbon (CDC) have been prepared by electrochemical etching of ternary layered carbide–Ti3SiC2 in molten CaCl2 at 900°C with 2.5 V and 3.0 V, respectively. Ti3SiC2 powder was pressed to form a pellet which was then served as the anode, and a graphite rod was used as the cathode. The obtained TiC product possesses a specific surface area of 653 m2 g−1 and a total pore volume of 0.56 cm3 g−1 with a narrow pore size distribution (average pore diameter of 2.0 nm). The obtained CDC material shows a layer graphene-like nanosheets structure, and amorphous carbon coexists with graphitic carbon ribbon in the product. The Raman analysis confirms that the ID/IG ratio of the CDC nanosheets is 1.17, indicating the lower degree of graphitization. The layered CDC nanosheets possess a specific surface area of 623 m2 g−1 and a total pore volume of 2.06 cm3 g−1 with an average pore diameter of 20–70 nm. It is suggested that the molten salt electrochemical etching process is a novel method for the production of 2-D multilayer material with tuned pores, and have penitential to be used for a variety of applications.

Formation of Ti3SiC2 interphase coating on SiCf/SiC composite by electrophoretic deposition

AbstractTo improve the oxidation resistance of SiC composites at high temperature, the feasibility of using Ti3SiC2 coated via electrophoretic deposition (EPD) as a SiC fiber reinforced SiC composite interphase material was studied. Through fiber pullout, Ti3SiC2, due to its lamellar structure, has the possibility of improving the fracture toughness of SiCf/SiC composites. In this study, Ti3SiC2 coating was produced by EPD on SiC fiber; using Ti3SiC2‐coated SiC fabric, SiCf/SiC composite was fabricated by hot pressing. Platelet Ti3SiC2 powder pulverized into nanoparticles through high‐energy wet ball milling was uniformly coated on the SiC fiber in a direction in which the basal plane of the particles was parallel to the fiber. In a 3‐point bending test of the SiCf/SiC composite using Ti3SiC2‐coated SiC fabric, the SiCf/SiC composite exhibited brittle fracture behavior, but an abrupt slope change in the strength‐displacement curve was observed during loading due to the Ti3SiC2 interphase. On the fracture surface, delamination between each layer of SiC fabric was observed.

Effect of Molten NaCl on the Synthesis of Ti&lt;sub&gt;3&lt;/sub&gt;SiC&lt;sub&gt;2&lt;/sub&gt; Powders

Free Ti/Si/C powder mixtures with or without molten salt were heated under vacuum with various schedules. The effect of molten salt during synthesis on the morphology and phase composition of Ti3SiC2 powders were investigated. The combustion powders were analyzed by DSC, XRD, SEM and EDS. The results indicated that the existence of molten salt could promote the reaction process and decrease the synthesis temperature. The Ti3SiC2 powders obtained by molten salt method were uniform and well dispersive. The content of Ti3SiC2 phase was influenced by salt/powders ratio and molding pressure. The appropriate salt/powders ratio and pre-press pressure were 1:1and 100 MPa, respectively.

Electromagnetic and microwave absorption properties of SiO2-coated Ti3SiC2 powders with higher oxidation resistance

Dense SiO2-coated Ti3SiC2 powders were prepared by the representative Stober route and heat treated process. The phase composition, microstructure, dielectric and microwave absorbing properties of the powders were characterized. XRD pattern reveals the existence of amorphous SiO2 and SEM image shows the SiO2 layer uniformly coated on Ti3SiC2 powders. Both the real and imaginary part of complex permittivity for the SiO2-coated Ti3SiC2 powders decrease due to the insulating SiO2 coating hiders the polarization and electric conductance loss effect. The oxidation resistance of the dense SiO2-coated Ti3SiC2 powders at high temperature was improved. Although the complex permittivity of the powders decrease after oxidized at 600 °C, the dense SiO2-coated Ti3SiC2 powders have larger dielectric constant compared with the bare Ti3SiC2 powders. In addition, the dense SiO2-coated Ti3SiC2 presents better microwave absorption performance after oxidation. The results indicate the dense SiO2 coating can improve oxidation resistance as well as microwave absorption performance of the Ti3SiC2 powders.

Electromagnetic and Microwave Absorption Properties of Hybrid FeCrAl/Ti3SiC2 Composite in X-Band

Hybrid magnetic–dielectric absorbers for electromagnetic applications consisting of FeCrAl and Ti3SiC2 powders have been fabricated by a ball-milling process and their electromagnetic characteristics and microwave absorption performance investigated in the frequency range from 8.2 GHz to 12.4 GHz. The dielectric loss increased with increasing Ti3SiC2 content, while the magnetic loss decreased. The electromagnetic parameters of the hybrid FeCrAl/Ti3SiC2 powders could be adjusted by adding various contents of Ti3SiC2. The hybrid powder with 20 wt.% Ti3SiC2 and 80 wt.% FeCrAl presented the most favorable microwave absorption performance. For the sample with thickness of 2.6 mm, effective absorption (<−10 dB) was obtained in the frequency range from 8.4 GHz to 12.1 GHz with a minimum value of −43.6 dB at 9.7 GHz. These results indicate that hybrid FeCrAl/Ti3SiC2 powders with appropriate weight ratio present better absorption performance than FeCrAl powder alone. This study makes a significant contribution to exploration of microwave absorption materials with low density, thin thickness, broad absorption bandwidth, and strong absorptivity.

Dielectric properties of Al-doped Ti3SiC2 as a novel microwave absorbing material

Al-doped Ti3SiC2 powders were synthesized by solid state reaction under a vacuum atmosphere from Ti/Si/TiC powders, with an optimum Al doping content. Results showed that the Ti3SiC2 major phase could be generated at a temperature as low as 1250°C through Al doping, and that the doped powders had a relatively narrow particle size distribution with a good dispersibility. The formation of Ti3Si1−xAlxC2 solid solution was further proved by XPS. The microwave dielectric parameters and reflection loss of the prepared Al-doped Ti3SiC2 samples were determined in the frequency range of 8.2–12.4GHz. It was found that the sample synthesized at 1350°C showed the high values in both the imaginary part of permittivity ε″ and dielectric loss tanδ, which were 4.39–7.32 and 0.57–0.78, respectively. For the microwave absorbing coating with a 2.6mm thickness of the sample, a better reflection loss of almost below −12dB was obtained in the whole frequency range of 8.2–12.4GHz.

Ti3SiC2 Reinforced ZA27 Alloy Composites with Enhanced Mechanical Properties

This work reports the fabrication and mechanical properties of Ti3SiC2 reinforced Zn‐27 wt. % Al alloy (denoted as ZA27). A total of 10–40 vol. % Ti3SiC2 reinforced ZA27 alloy composites were synthesized by hot pressing mechanically alloyed mixtures of Ti3SiC2 and ZA27 powders. Among the fabricated composites, 20 vol. % Ti3SiC2/ZA27 composite possesses the highest room temperature tensile strength, bending strength and Vickers hardness of 339 MPa, 593 MPa, and 1.13 GPa, respectively. The improved mechanical properties of the 20 vol. % Ti3SiC2/ZA27 composite are mainly attributed to the effects of fine‐grain strengthening and dispersion strengthening.