Ti3SiC2 Composites Research Articles

Field-assisted sintering of MC-Ti3SiC2 composites with adjustable thermal expansion coefficient

Tool materials for precision glass moulding made of WC or SiC bear the risk of glass breakage due to a difference in the coefficient of thermal expansion (CTE) between the mould and the glass. The aim of this study is to develop a MAX phase composite with increased CTE and thus reduced CTE difference. A mixture of Ti3SiC2 and 10 vol% SiC powder was sintered between 1250 °C and 1350 °C using the field-assisted sintering technique (FAST). In addition to the sintering temperature, the dwell time and the initial particle size were varied using a full factorial experimental design. Complete densification, homogeneous carbide distribution and no grain coarsening were observed for specimens sintered at 1300 °C for 10 min at 50 MPa. The grain size of SiC and Ti3SiC2 is approximately 0.3 μm, although larger grains occasionally occur. Identified process parameters were successfully transferred to TiC reinforced Ti3SiC2 composites. While the carbide content can be specifically controlled by mixing, the MAX phase partially decomposes during sintering. MC additions between 10 and 30 vol% resulted in an adjustable CTE in the range 6.8–9.0 ppm/K.

Fabrication of TiC coated short carbon fiber reinforced Ti3SiC2 composites: Process, microstructure and mechanical properties

The Cf/Ti3SiC2 composites were fabricated through spark plasma sintering (SPS) and hot isostatic pressing (HIP), TiC coated Cf and Ti3SiC2 powder were used as starting materials. The improved fracture toughness (KIC) and Vickers hardness (HV1) of the TiC coated Cf/Ti3SiC2 composite fabricated by SPS were 7.59 MPa·m1/2 and 7.28 GPa. On this foundation, taking the advantage of better sintering process of HIP, the highest KIC and HV1 achieved 8.32 MPa·m1/2 and 9.24 GPa with fiber content of 10 vol%, which increased by 40% and 65% compared with that of monolithic Ti3SiC2. The reasonable control of reactive interface is the main factor for the improved mechanical properties of the composites, the TiC coating effectively protected the fiber structure from interfacial reaction compared with that of the non-coated Cf/Ti3SiC2. Meanwhile, the artificially designed and weakly bonded TiC coated Cf can fully exert the toughening mechanisms like fiber pull-out and debonding.

Mechanical properties and oxidation behavior of SiCf/Ti3SiC2 composites prepared by hot isostatic pressing

AbstractSiCf /Ti3SiC2 composites were fabricated by hot isostatic pressing using Ti3SiC2 powder and SiCf as starting materials at 1200°C for 2 h. A maximum flexural strength of 498 MPa and a fracture toughness of 6.76 MPa·m1/2 were achieved for a composite with 5 vol% SiCf and the microhardness reached 1068 HV1 with 25 vol% SiCf. SiC and Ti3SiC2 are thermodynamically stable according to the Ti–Si–C phase diagram. However, microstructure analysis showed that the SiCf was distributed uniformly in the Ti3SiC2 matrix with an interfacial layer that was composed of TiC and SiC. Elemental Al agglomeration in the Ti3SiC2 matrix occurred in this reaction layer, which was considered the inducing factor for the occurrence of the interfacial reaction. The interfacial reaction was intense with a low fiber content. Oxidation testing suggested that the oxidation rate increased with SiCf introduction. The oxidation mass gain curve plateaued after 15 h.

Interfacial reactions and mechanical properties of SiC fiber reinforced Ti3SiC2 and Ti3(SiAl)C2 composites

In this paper, SiC fiber (SiCf) reinforced Ti3SiC2 and Ti3(SiAl)C2 composites were fabricated by spark plasma sintering at 1250 °C and 1300 °C for 10 min, respectively. The interfacial reactions between fibers and matrix, as well as the mechanical properties of the two composites, were investigated. XRD, SEM and TEM were used to characterize the phase compositions and microstructures of the as-synthesized composites. The results showed that no interfacial reaction occurred between SiCf and Ti3SiC2 matrix, while it occurred between SiCf fiber and Ti3(SiAl)C2 matrix. In the latter case, the interfacial reaction layer was mainly composed of SiC, TiC, and TiSi2 phases, and its thickness was about 1.2 μm. Besides, due to the introduction of SiC fibers, both bending strength and fracture toughness of two composites were improved. Based on the investigation of crack propagation, it was proposed that the main strengthening and toughening mechanism was crack bowing for SiCf/Ti3(SiAl)C2 composite, while was fiber pullout, fiber debonding, and residual thermal stress for SiCf/Ti3SiC2 composite.

Influence of Ti3SiC2 content on erosion behavior of Cu–Ti3SiC2 cathode under vacuum arc

In this study, a series of Cu–Ti3SiC2 composites with different Ti3SiC2 contents were prepared by spark plasma sintering. Their mechanical properties and electrical resistivity were investigated. Through analyzing the morphology and composition of the eroded regions, the effect of Ti3SiC2 content on the erosion behavior of Cu–Ti3SiC2 cathodes under vacuum arc was studied. Results show that the relative density and bending strength of the Cu–Ti3SiC2 composites decrease with the increasing Ti3SiC2 content, while the opposite holds for hardness and electrical resistivity. The morphology and phase composition of the erosion zone is dominated by the decomposition process and the amount of Ti3SiC2 in the cathode. Cu–Ti3SiC2 cathodes containing 10 mass%Ti3SiC2 or less displayed relatively flat eroded surface morphology. Cathodes with high Ti3SiC2 content suffered more serious erosion with voids, cracks, and severe decomposition of Ti3SiC2, all of which contribute to impairing the arc ablation resistance of the composite. Ti3SiC2 particles decomposed into TiC and Si vapor; eventually, this TiC also decomposed into Ti vapor and C, leaving a considerable amount of C on the arc affected cathode surface. Excess addition of Ti3SiC2 particles not only deteriorates the strength but also the electrical and thermal conductivity of the composite, both of which in turn harms the arc erosion resistance of the material. These results suggest that the optimal Ti3SiC2 content is below 10 mass% in the composite.

Synthesis of the CoNi nanoparticles wrapped Ti3SiC2 composites with excellent microwave absorption performance

The magnetic–dielectric composites with synergetic magnetic and dielectric losses have exhibited great potential in the practical applications of microwave absorbing material. This paper reports a simple low-temperature in situ hydrothermal approach for synthesizing novel composites composed of the dielectric Ti3SiC2 wrapped with magnetic CoNi nanoparticles. The microstructure, morphology, electromagnetic properties, and microwave absorption performance of as-synthesized samples were investigated. By adjusting the content of formed magnetic CoNi nanoparticles on the surface of Ti3SiC2, obvious regulated frequency-dependence of electromagnetic parameters for the proposed CoNi/Ti3SiC2 composites can be realized. Consequently, the effective absorption bandwidth (RL < −10 dB) and optimal reflection loss value of CoNi/Ti3SiC2-40 composites under thinner thickness of 1.55 mm can reach up to 4.88 GHz and −41.41 dB, respectively. Exceptional microwave absorption performance of the CoNi/Ti3SiC2 composites is attributed to its simultaneously improved attenuation characteristics and optimized impedance matching, and thus can be undoubtedly identified as high-efficiency microwave absorbing material.

Fretting wear of spark plasma sintered Ti3SiC2/GNP ceramic composite against Si3N4

Fretting wear characteristics of Ti3SiC2 reinforced with 1%, 3%, 5%, 10% and 15% graphene nanoplatelets (GNP) are presented in this paper. Ti3SiC2/GNP composite was developed using spark plasma sintering at a temperature of 1200 °C. The tests were conducted to investigate the effect of GNPs on the tribological properties of Ti3SiC2·Ti3SiC2/GNP composites fabricated through spark plasma sintering. Higher densification was obtained, resulting in higher values of Vickers Microhardness in the case of spark plasma sintered Ti3SiC2/GNP, as compared to Ti3SiC2. The friction coefficient and wear rate of GNP reinforced Ti3SiC2 composites were significantly improved, as compared to virgin Ti3SiC2. The composite with 15% GNP showed the lowest friction coefficient of 0.1416 and a wear rate of 5×10−5 mm3/Nm, whereas virgin Ti3SiC2 showed a higher coefficient of friction and wear rate of 0.3264 and 17.22×10−4 mm3/Nm, respectively. Although the formation of the oxide film was observed on the wear track, however, adhesive and delamination wear were observed as dominant wear mechanisms. The spark plasma sintering proved to be the most effective technique for increasing hardness and tribological properties of Ti3SiC2/GNP composite.

Fabrication of SiCw/Ti3SiC2 composites with improved thermal conductivity and mechanical properties using spark plasma sintering

High strength SiC whisker-reinforced Ti3SiC2 composites (SiCw/Ti3SiC2) with an improved thermal conductivity and mechanical properties were fabricated by spark plasma sintering. The bending strength of 10 wt% SiCw/Ti3SiC2 was 635 MPa, which was approximately 50% higher than that of the monolithic Ti3SiC2 (428 MPa). The Vickers hardness and thermal conductivity (k) also increased by 36% and 25%, respectively, from the monolithic Ti3SiC2 by the incorporation of 10 wt% SiCw. This remarkable improvement both in mechanical and thermal properties was attributed to the fine-grained uniform composite microstructure along with the effects of incorporated SiCw. The SiCw/Ti3SiC2 can be a feasible candidate for the in-core structural application in nuclear reactors due to the excellent mechanical and thermal properties.

Evaluation of properties of spark plasma sintered Ti3SiC2 and Ti3SiC2/SiC composites

Abstract The powder mixtures of Ti, Si, TiC and Al were sintered to synthesize Ti3SiC2 and Ti3SiC2/SiC by spark plasma sintering (SPS) method. Single phase Ti3SiC2 and Ti3SiC2/SiC composites were obtained by sintering Ti/1.1Si/2TiC/0.2Al and 2.2Si/3TiC/0.2Al at 1400 °C, for 15 min, under a pressure of 50 MPa, respectively. The reduction of Al and Si contents in the starting powder mixture led to the formation of TiC impurity phase. X-ray diffraction (XRD) and Rietveld analyses were used to evaluate the phase constituents. The main objective of this study was to reveal the properties of single phase Ti3SiC2 and to evaluate the development of the mechanical and tribological properties of Ti3SiC2/SiC comprehensively. The results indicated that the SiC in situ reinforced Ti3SiC2 composites exhibited higher hardness, fracture toughness and wear resistance compared to single phase Ti3SiC2.

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.

Mechanical, thermal physical properties and thermal shock resistance of in situ (TiB2+SiC)/Ti3SiC2 composite

Dense (TiB2+SiC)/Ti3SiC2 composite with 20 vol% TiB2 and 10 vol% SiC was synthesized by in situ reaction hot pressing. The room and high temperature mechanical and thermal physical properties, as well as thermal shock resistance of the composite were investigated and compared with SiC/Ti3SiC2 composite as prepared by the same process. The synergistic action of TiB2 and SiC produced a significant strengthening and toughening effect and (TiB2+SiC)/Ti3SiC2 composites exhibit superior room- and high-temperature mechanical properties compared with SiC/Ti3SiC2 composite. Especially, (TiB2+SiC)/Ti3SiC2 composite shows higher Young's modulus from 25 °C to high temperature and can retain a high modulus of 313 GPa (about 81% of room temperature value) up to 1200 °C. From 25 °C to 800 °C, (TiB2+SiC)/Ti3SiC2 composite has higher thermal conductivity and slightly lower coefficient of thermal expansion. Both water quenching test results and calculation of thermal shock resistance parameters, R, Rst and RIV indicate an improved thermal shock resistance of (TiB2+SiC)/Ti3SiC2 composite, with an increase of the critical thermal shock temperature difference ΔTc from 325 °C for SiC/Ti3SiC2 to 440 °C for (TiB2+SiC)/Ti3SiC2. Superior properties render (TiB2+SiC)/Ti3SiC2 composite a promising prospect as high temperature structural materials.

Experimental Investigation on Microstructure and Mechanical Properties of cBN–Ti3SiC2 Composites

In this study, a recently developed superhard and high‐performance composite of cubic boron nitride–titanium silicon carbide (cBN–Ti3SiC2) is fabricated at high‐pressure and high‐temperature (HPHT) condition. The mechanical properties of this superhard material are investigated using the comparisons of the bending, compression hardening, and Vicker hardness test. Its microstructural properties are characterized by X‐ray diffraction and scanning electron microscopy. The influence of the binder Ti3SiC2 is determined by changing the mass ratio. The composites with common binders, namely, TiC and SiC2, are sintered under the same HPHT condition to investigate the characteristics of cBN–Ti3SiC2 composites.

Microstructure and mechanical properties of in-situ hot pressed (TiB2 + SiC)/Ti3SiC2 composites with tunable TiB2 content

Without impurity phases detected, fully dense (TiB2 + SiC)/Ti3SiC2 composites have been successfully synthesised by in-situ reaction hot pressing. The effect of TiB2 content on phase composite, sintering properties, microstructure, and mechanical properties of the composites were thoroughly investigated. With TiB2 content increasing from 0 to 50 vol.-%, the flexural strength increases first and then decreases, whereas fracture toughness, hardness and modulus show a linear increase. The maximum strength of 826 MPa was obtained at 20 vol.-% TiB2. On the whole, the (TiB2 + SiC)/Ti3SiC2 composites exhibit a superior comprehensive mechanical properties superior to other reported Ti3SiC2-based composites reinforced by singular reinforcement. The significant strengthening and toughening effect induced by the in-situ incorporated TiB2 can be ascribed to the unique properties of TiB2 and the synergistic action of many mechanisms including particle reinforcement, pulling out of grains, crack deflection and grain refinement strengthening.

Pore and microstructure change induced by SiC whiskers and particles in porous TiB2–TiC–Ti3SiC2 composites

TiB2–TiC–Ti3SiC2 porous composites were prepared through a plasma heating reaction using powder mixtures of Ti, B4C SiC whiskers (SiCw) and SiC particles (SiCp). The effects of the SiCw and SiCp content on pore structures, phase constituents, microstructure, and crystal morphology of TiC were studied. The results show that TiC, TiB, Ti3B4 phases are formed within the 5Ti+B4C system. With the addition of SiCw and SiCp, the TiB and Ti3B4 phases are reduced, sometimes even disappeared. Interestingly, the content of TiB2 and TiC increased, resulting in Ti3SiC2 and TiSi2 being formed. The porosity of composites increases notably with the addition of SiCw. However, with the increase of SiCp, the porosity of the composites first decreases, followed by an increase. After adding the specified amount of SiCw/SiCp, the compressive strength of composites are improved significantly. Additionally, the pore size of the composites are decreased significantly with the addition of SiCw/SiCp. During the plasma heating process, some Si atoms will diffuse into the TiC lattice, which in turn made the cubic TiC grains into hexagonal lamellar TiC or Ti3SiC2 grains.

Microstructure and Oxidation of (La,Sr)CrO3-Added Ti3SiC2 Composites.

Composites of Ti3SiC2-(10, 20, 40)wt% La0.8Sr0.2CrO3 were synthesized by hot pressing powders of Ti3SiC2 and La0.8Sr0.2CrO3. These powders reacted to form stable TiC carbides and LaTiO3, Cr2Ti4O11, La2O3, and SrCrO4 oxides during hot pressing. The composites consisted primarily of a fine TiC-rich matrix phase and coarse Ti3SiC2 dispersoids. The addition of oxidation-immune La0.8Sr0.2CrO3 into Ti3SiC2 increased the oxidation rate because TiC formed during hot pressing. During oxidation of the composites at 800-1000 degrees C for 100 h in air, Ti diffused outward to form an outer rutile-TiO2 layer, and oxygen transported inward to form an inner oxide layer.

Erosion of Cu–Ti3SiC2 composite under vacuum arc

Pure Cu–Ti3SiC2 composites, with 1, 3, 10, 15 and 25 wt.% of Ti3SiC2, were prepared by means of powder metallurgy method. Erosion behavior of the composites under vacuum arc was investigated. The eroded surfaces and the phase constituent of the eroded composite were revealed by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and a 3D super depth digital microscope. Results indicated that Ti3SiC2 particles are more prone to be damaged by the vacuum arc than the Cu matrix. The decomposition of Ti3SiC2 was detected on the surfaces of both anode and cathode. As the number of arcing increase the Ti3SiC2 content on the cathode surface graduate declines. The erosion rate of Cu–Ti3SiC2 composites increased with increasing Ti3SiC2 content.

Processing, microstructure and ablation behavior of C/SiC–Ti3SiC2 composites fabricated by liquid silicon infiltration

In order to improve the ablation resistance of C/SiC composites, Ti3SiC2 was in situ formed in C/SiC composites by a joint process of slurry infiltration and liquid silicon infiltration (LSI). Both the mass ablation rate and linear ablation rate of C/SiC composites decrease with the introduction of Ti3SiC2 matrix. Compared with C/SiC composites, the low level of porosity and the existence of protective oxide layer lead to the better ablation resistance of C/SiC–Ti3SiC2 composites.

Tribological performance of Ni3Al–15 wt% Ti3SiC2 composites against Al2O3, Si3N4 and WC-6Co from 25 to 800 °C

Dry sliding tribological tests of Ni3Al matrix self-lubricating composites (NMSC) with addition of 15wt% Ti3SiC2 are undertaken against Si3N4, Al2O3, WC-6Co at 25–800°C. The results show that the tribological properties are strongly dependent on the counterface materials. NMSC against Si3N4 shows the lower friction coefficients (0.31–0.48) and wear rates (0.34–2.1×10−5mm3N−1m−1) from 25 to 800°C, while there is no clear difference in tribological performance of NMSC against Al2O3 or WC-6Co. NMSC against Si3N4 may be the optimal design for the excellently tribological performance.

Friction and wear behavior of NiAl–10 wt%Ti3SiC2 composites

The effect of sliding speed and load on the friction and wear behavior of NiAl–10wt%Ti3SiC2 composites (NAT) at room temperature was investigated through determination of friction coefficients and wear rates in different conditions and analysis of morphologies and compositions of wear debris and worn surfaces of both NAT and Si3N4 ball. The results showed that the friction coefficients decreased and wear rates increased with increase in load, whereas they both decreased with increase in sliding speed. The transition in the wear mode from mild to severe wear was strongly influenced by the sliding speed and load.

Effect of sintering temperature on the preparation of Cu–Ti3SiC2 metal matrix composite

Ti3SiC2 has the potential to replace graphite as reinforcing particles in Cu matrix composites for applications in brush, electrical contacts and electrode materials. In this paper the fabrication of Cu–Ti3SiC2 metal matrix composites prepared by warm compaction powder metallurgy forming and spark plasma sintering (SPS) was studied. The stability of Ti3SiC2 at different sintering temperatures was also studied. The present experimental results indicate that the reinforcing particles in Cu–Ti3SiC2 composites are not stable at and above 800°C. The decomposition of Ti3SiC2 will lead to the formation of TiC and/or other carbides and TiSi2. If purity is the major concern, the processing and servicing temperatures of the Cu–Ti3SiC2 composite should be limited to 750°C or lower. The composites prepared by warm compaction forming and SPS sintering at 750°C have lower density when compared with the composites prepared by SPS sintering at 950°C, but their electrical resistivity values are very close to each other and even lower.