TiC Addition Research Articles

Effect of heat treatment temperature on the microstructure and microhardness of TiC/Ti6Al4V composite manufactured with laser metal deposition

This study presented the investigation of the influence of post heat treatment temperature on the microstructure and hardness of TiC/Ti6Al4V composite manufactured with laser metal deposition. Heat treatment was performed to improve the microstructural homogeneity. It was found that the addition of TiC into Ti6Al4V results in the formation of a Widmanstätten microstructure with different grain sizes on the matrix. Heat treatment of the TiC/Ti6Al4V promoted phase transformations from acicular in the as built to lamella (α + β) and equiaxial phases in the heat-treated samples. The 900°C heat treated sample showed a uniform distribution of α and β phases, and 1100°C showed an increase in β phases, which resulted in an equiaxial microstructure. Moreover, Heat treatment at 1100°C resulted in the highest microhardness of 665±13HV.

Obrada struganjem kaljenih čelika alatima od PcBN

The paper discusses the results of the experimental investigation of the performance of several grades of PcBN cutting composites in conditions of the interrupted machining of hardened steel. Both BH and BL types of PcBN indexable inserts with additions of Si3N4, TiC, and TiCN were tested, and cutting speed varied to assess the possibility of applying these cutting tools in different conditions. It has been shown that BL PcBN can be utilized for turning with shock loads in case of high cutting speed and low depth of cut (0,2 mm). While in the range of comparatively low cutting speeds BL cutting tools are actually inoperable, and because of microchipping of polycrystalline fragments and brittle destruction of the cutting edge, an increase of the cutting speed to 210 m/min changes wear pattern and formation of the wear land. As well as this, measurement of the form and values of the cutting forces impulses revealed the effect of their peak growth by up to 40%. The danger of shock impulses was analyzed by FEM modeling, and it was demonstrated that during impacts, the maximal value of the third Principal stress exceeds the average level of compressive stresses during continuous cutting by 1.6 times, which can cause damage to the cutting tool. The data on the estimation of tool fracture probability depending on loading conditions are presented, and the possibility of reducing such probability is shown.

Comparative evaluation of TiC and/or WC addition on microstructure, mechanical properties, thermal residual stress and reciprocating wear behaviour of ZrB2–20SiC composites

Comparative evaluation of TiC and/or WC addition on microstructure, mechanical properties, thermal residual stress and reciprocating wear behaviour of ZrB2–20SiC composites

Effect of TiC on the microstructure of GTD-111 superalloy processed by laser powder bed fusion

• TiC particles cause heterogeneous nucleation by altering the diffusion field in LPBF. • GBs liquation and GBs cracking is the most important LPBF problem in GTD-111. • The addition of TiC to GTD-111 causes the formation of equiaxed grains and zigzag of GB. • The favorable thermal conductivity of TiC prevents crystal formation in the GTD-111 matrix. • GTD-111 composite with TiC reduces the tendency of GB cracking by increasing C-GBLD. In this study, the microstructure of specimens made of GTD-111 superalloy was modified by laser powder bed fusion with TiC nanoparticles. The results showed that TiC particles acted as heterogeneous nucleation for solidification and caused grain refinement, equiaxed grain formation, grain boundary length reduction, increase of large angle grain boundaries, zigzagging of grain boundary, reduction of cracks and porosity and also reduces the segregation of elements sensitive to melting cracks. The combination of the above factors reduced the grain size by adding TiC by 40%.

Experimental analysis, statistical modeling, and parametric optimization of quinary-(CoCrFeMnNi)100 –x/TiCx high-entropy-alloy (HEA) manufactured by laser additive manufacturing

For additional strength increase, 5, 10, and 15% TiC was added to the quinary CoCrFeMnNi high entropy alloy (HEA) at laser powers of 100, 400, and 700 watts while selective laser melting method was engaged in the fabrication. Microstructure, porosity, density, yield and tensile strengths, elongation, and microhardness are among the parameters analyzed. As TiC appreciated from 5 to 15%, the microstructure revealed that the particles were dispersed within the matrix. Also, the addition ensued grain size refinement with increasing particle proportion. Meanwhile, 15% caused an increase in porosity, 0–10% TiC dosage and 100–700 watts laser power led to a decrease in porosity. The same dosage of TiC resulted in a linear improvement in microhardness even as 0–15% TiC ensued gradual reductions in density and elongation Increases in laser power between 100 and 700 watts were detrimental to elongation but beneficial to density and microhardness enhancement. For composites produced at 100–700 watts laser power, 5–10% TiC increased yield and ultimate tensile strengths whereas 15% TiC decreased strength. For every TiC addition, laser power 100 - 400 watts generally showed an improvement in strength and microhardness, whereas 700 watts depicted a decrease in strength and microhardness. The optimal input combination was predicted by the developed models to be 15% TiC and 504 watts laser power. Since the deviation between anticipated outcome and validation values for the responses is < 0.05, the models are certified for future prediction of the responses. In conclusion, with 504 watt laser power, the entropy alloy's optimum composition is (CoCrFeMnNi)85/TiC15.

Comparative study on process-structure-property relationships of TiC/Ti6Al4V and Ti6Al4V by selective laser melting

Titanium matrix composites (TMCs) have gained tremendous attention due to their excellent mechanical properties by combining the advantages of Ti6Al4V matrix and ceramic reinforcement. In current study, the selective laser melting (SLM) technique is applied to manufacture TiC/Ti6Al4V and Ti6Al4V. Systematic characterization and analysis are conducted to reveal and compare their process-structure-property relationships. The results reveal that the near fully dense parts could be manufactured by process optimization upon the systematic investigation on their densification behaviors. The addition of TiC effectively refines the matrix grain and changes the microstructures. The SLM-manufactured (SLM-ed) Ti6Al4V exhibits typical coarse columnar grains with ultrafine lamellar α+β microstructures distributed inside (average α-lath thickness: 282 nm). Nevertheless, the SLM-ed TMCs possess a peculiar molten pool morphology, in which the sub-columnar grains grow upward along the direction of the steepest temperature gradient. The acicular nanoscale TiC is dispersed inside the sub-columnar grains, while the chain-like TiC is distributed along the boundary. Meanwhile, an evolution process is proposed to describe the microstructure evolution of the SLM-ed TMCs. The interrelationships between energy density and resulting microstructures are also identified, based on which, strong and ductile Ti6Al4V specimens (tensile strength: 1390 MPa, elongation: 9.66%) and ultra-strong TMCs specimens (tensile strength: 1538 MPa) are manufactured. The strengthening effects are mainly attributed to the Hall-Petch strengthening and load-bearing transformation. Fracture analysis indicates that the failure of the SLM-ed Ti6Al4V is caused by the micro-voids nucleation and coalescence at the interface of α and β phases, whereas the premature fracture of the SLM-ed TMCs is originated from the chain-like TiC.

Directed energy deposition of AA7075 - Effect of TiC nanoparticles on microstructure

AA7075 alloy is a high-strength aluminum alloy with properties enhanced by heat treatments. However, like most high-strength aluminum alloys, AA7075 is non-weldable, as it suffers from hot cracking when it is welded or additively manufactured with fusion techniques. A proposed way to reduce the hot cracking tendency is by refining the microstructure by adding nucleation enhancers. In this study, AA7075 powder feedstock was functionalized with 1.7 and 3.4 vol% TiC nanoparticles, printed with laser-directed energy deposition (DED), subjected to T6 heat treatment, and characterized with optical and electron microscopy, electron backscatter diffraction (EBSD), and hardness measurements. Although TiC was not homogeneously distributed in the aluminum matrix, the addition of TiC successfully suppressed hot cracking by inhibiting dendritic growth produced by increased and more uniform nucleation, which resulted in refined equiaxed grains, and thus enhanced the printability of the material.

Microstructures and mechanical properties of TiB2 composite ceramics with co-addition of Ti and TiC fabricated by SPS

TiB2 composite ceramics containing different amounts of Ti and TiC were fabricated via spark plasma sintering (SPS), and effects of their addition contents on the microstructure and mechanical properties were discussed. The newly formed phases of TiB with a cubic lattice structure in the composite ceramics were observed. At a relatively low temperature of 1510 °C, pressure of 50 MPa, and holding time of 5 min, the TiB2 composite ceramic with 30 wt% TiC and 10 wt% Ti additions acquired an excellent strength of 727 MPa and a high toughness of 7.62 MPa m1/2. The improvement in strength and toughness was attributed to the mixed fracture mode, second phase strengthening, and increased energy consumption for crack propagation caused by the newly formed phases and fine TiC particles. In addition, the significant effects of the Ti and TiC addition contents on the densification temperature and mechanical properties of the composite ceramics were determined using analysis of variance (ANOVA).

High temperature performance of 316L steel reinforced by particle inoculation and processed by laser powder bed fusion

Grade 316 L is one of the most versatile austenitic stainless-steel products whose potential in laser powder bed fusion has been recently evaluated. A way of improving its properties is to add reinforcements, such as TiC nanoparticles, to promote dispersion hardening. However, it is often difficult to assess microstructure-mechanical property relationships, since particle inoculation promotes heterogeneous nucleation of equiaxed grains during rapid solidification. In this work, two 316 L samples were manufactured by laser powder bed fusion, where the powder of one of them was inoculated with TiC nanoparticles. The effect of inoculants on the microstructure and its high temperature behavior was assessed. Electron Probe Micro Analyzer proved that inoculants did not get dissolved during the printing process and they predominately lay in the intercellular regions, which were solute enriched. Advanced characterization proved that inoculation did not affect the solidification structure, which remained cellular and with a similar size, or the grain size, although it did modify the bulk texture. Finally, the effect of dispersion hardening on the behavior at high temperature of a 316 L steel was evaluated by small punch tests, which proved that the addition of TiC improves all, ductility, yield strength and ultimate tensile strength at high temperature. Moreover, samples processed by LPBF showed high temperature behavior and superior strength and ductility, as compared to the ones obtained in a reference annealed steel, even though the grain size obtained in the former case was at least 50 times larger than the one obtained for the reference condition.

Nano-TiC reinforced [Cr–Fe4Co4Ni4]Cr3 high-entropy-alloy composite coating fabricated by laser cladding

The agitator blade made by 904 L stainless steel was subjected to serious corrosion-wear due to its low hardness in phosphoric acid reactors. In this aspect, various nano-TiC reinforced [Cr–Fe4Co4Ni4]Cr3 HEA composite coatings were designed using the cluster-plus-glue-atom model and fabricated on 904 L stainless steel by laser cladding. The phase structure of the composite coatings was composed of FCC solid solution and TiC phase. The microstructure observation detected that tiny TiC particles widely distributed along the inter-dendrites of FCC matrix. Also, the particle dimensions and volumes rapidly enhanced with the addition of TiC. Whereas, excessive TiC contents (≥12.5vol%) led to the generation of microcracks. The TEM results further confirmed that TiC particles did not decompose during laser cladding. With the addition of TiC, the microhardness, wear and corrosion resistance of the composite coatings gradually increased. Especially, the microhardness of [Cr–Fe4Co4Ni4]Cr3-15vol%TiC composite coating reached the peak value of 357.4 HV0.2, approximately twice higher than that of the substrate. It's specific wear rate (3.974 mm3 N−1 m−1) was lower than that of the substrate (5.545 mm3 N−1 m−1). Compared with 904 L stainless steel, the corrosion current density of [Cr–Fe4Co4Ni4]Cr3-15vol%TiC composite coating reduced by nearly an order of magnitude, the impedance increased by 3.5 times.

Selective Laser Melting of Inconel 718/TiC Composite: Effect of TiC Particle Size

In this article, we present the results of a study of the effect of TiC particle size on the microstructure and properties of a composite material based on the heat-resistant nickel alloy Inconel 718. Composite materials with the addition of 1% mass of micron- or nano-sized TiC particles were successfully manufactured by selective laser melting. Hot isostatic pressing and heat treatment were applied to manufactured samples. Increasing hardness with the addition of TiC particles by about 20% without dependence on TiC size was determined. The addition of nano-sized TiC leads to a greater increase in strength characteristics at room temperature and elevated temperature of 700 °C in comparison with pure Inconel 718 and the addition of micron-sized TiC particles, but also leads to decreasing elongation.

Effect of Ti and TiC additions on the microstructure and wear resistance of high chromium white irons produced by laser directed energy deposition

Laser directed energy deposition (L-DED) is an additive technology that offers a rapid solution for repairing mining components made of High Chromium White Iron (HCWI) on site. However, the refined carbide morphology from the rapid cooling in L-DED is detrimental to the wear resistance of the repairs. In this study, two types of powder (Ti powder and TiC powder) were added to improve the wear resistance of L-DED HCWI. The Ti powder addition promoted the formation of in-situ TiC while the TiC powder addition resulted in coarse ex-situ TiC and fine in-situ TiC in the as-deposited microstructure. The addition of both powders destabilised the austenitic matrix (γ-Fe). The wear resistance was investigated by a high stress abrasion test using silica sand (softer than M7C3) and a pin-on-disk wear test using a ruby pin (significantly harder than M7C3). The best wear results were achieved with 6.55 wt% Ti powder addition. This destabilised γ-Fe in the as-deposited microstructure which underwent strain-induced martensite formation during the high stress abrasion wear testing, improving the wear resistance of the alloy. The addition of TiC powder improved the wear resistance in the high stress abrasion test due to the increase in the fraction of carbide. In the pin-on-disk wear test, the alloys with TiC powder addition performed better than the cast sample because a greater amount of γ-Fe matrix in the microstructure provided a better combination of hardness and ductility.

Prospects and State of the Glass Industry in Saudi Arabia and a preliminary assessment of the quality of Glass and Glass-Ceramics Fabrication

Although the economic value of glass products and its importance to the Saudi National Economy is vast, not much information is available about the current state of the art of the industry. Likewise little information is available about the geography, potential sites for mining sand as well as the evaluation of sand quality. This paper attempts to bridge this gap by presenting a feasibility study of fabricating normal glass and glass ceramics from Saudi Arabia’s domestically available raw materials. It discusses the current status of glass industry in Saudi Arabia and the Middle East region. It also gives a brief explanation about the sand topography in Saudi Arabia. In order to determine the feasibility of fabricating glass using these raw materials, experimental data on the fabrication of normal glass and glass-ceramics from indigenously available raw materials was obtained and reported as part of the findings of this paper Firstly, normal transparent glass were able to be fabricated without any apparent large defects using sand collected from Ar-Rayis region in Saudi Arabia. Four nano-sized crystallization catalysts, namely VC, WC, TiC and Y&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, were added to the constituents of the glass in 3 wt.%. For VC, the crystallization process was limited. The glass ceramics of WC consisted of multi-dimensional edges crystals which covered all the matrix. Gray crystalline whiskers were obtained by addition of TiC. The Y&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;- glass ceramics consisted of multi-directionally rosette crystals. Finally, the microhardness values of the added crystallization catalysts glass ceramics were obtained and found to be much higher compared to normal glass. The results show that glass of high quality can be produced specifically for Ar—Rayis region which would be of interest to researchers, glass industry personnel and potential investors

Improvement of mechanical properties and corrosion resistance for wire arc additive manufactured nickel alloy 690 by adding TiC particles

Nickel alloy 690 (Ni690) were fabricated by wire arc additive manufacturing (WAAM) with three kinds of TiC particles adding contents (no TiC addition, 0.5 wt% TiC, 1.0 wt% TiC) based on cold metal transfer (CMT) technology. The effects of TiC particles adding content on the microstructure, mechanical properties and corrosion resistance were investigated. After adding 1.0 wt% TiC particles, the average length of the γ grains decreased from 301 ± 61 µm to 114 ± 15 µm and the structure of grains changed from columnar dendrite into equiaxed dendritic at the top of each layer, which is results of the heterogeneous nucleation and increase of constitutional supercooling caused by TiC particles. The difference between horizontal and vertical mechanical properties of WAAM Ni690 component disappeared because the heterogeneous nucleation caused by TiC particles prevented the epitaxial growth. The ultimate tensile strength of the WAAM 1.0TiC-Ni690 component reached 590 MPa in both directions, which increased 10 % compared with no TiC addition. The improvement of mechanical properties was owing to the grain refinement and the formation of reinforcing TiC/(Ti, Nb)C second-phase particles. The potentiodynamic polarization tests showed that the improved corrosion resistance with the increased content of TiC particles. The electrochemical impedance spectroscopy (EIS) tests results showed that due to the refined γ columnar grains providing more nucleation sites, a denser and thicker passive film was formed, which improved the corrosion resistance. The composition of the passive film was analyzed by X-ray photoelectron spectroscopy (XPS). The results reflected the more content of oxides and hydroxides of Cr in the passive film of WAAM 1.0TiC-Ni690 sample represented the denser passive film and better corrosion resistance.

Influence of TiC addition on ablation and thermal shock behaviour of microwave sintered ZrB2–SiC–TiC composites

Ultra-high temperature ceramics should possess excellent ablation and thermal shock resistance in order to endure severe temperatures for ultra-high temperature space applications. The study reports the effect of TiC (5–10 vol. %) addition on ablation and thermal shock resistance of microwave sintered ZrB2-25 SiC (vol. %) composites. The ablation and thermal shock resistance improved with TiC addition due to the formation of TiO2 and ZrO2.TiO2 layers on the surface of oxidized composites. The composites retained up to 91.95% of maximum hardness and 91.61% of maximum fracture toughness after ablation. Crack deflection and crack bridging were observed as the primary toughening mechanisms after ablation. The thermal shock resistance also improved with TiC addition. The analytically estimated thermal shock parameters as well as the experimentally measured critical temperature difference increased with TiC addition. The enhancement in thermal shock resistance was ascribed to the higher flexural strength and fracture toughness of developed composites.

Effect of recycled TiC addition in the compaction and sintering behavior of Al-Mg-Cu-Zn + r-TiC powder metallurgy composites

The radical increase in daily use of metal matrix composites with ceramic reinforcements tangibly increases scrap, which contains valuable ceramic materials. As hard ceramic materials are cost-intensive, there is a significant necessity for their recovery and recycling at all times. This work attempts to recover valuable titanium carbide particles from a scrap of in-situ synthesized AA7075-TiC composites for reuse as reinforcements. The TiC particles were recovered by the corrosive chemical extraction method and analyzed for morphologies, such as shape, phase, and size using scanning electron microscopy, x-ray diffraction, and dynamic light scattering techniques. Further, Al-Mg-Cu-Zn powder was blended with various percentages of the recovered TiC particles to investigate the characteristics of the blends. The compressibility behavior of various blends is correlated with linear and non-linear models, which identified that the Kawakita and modified Cooper-Eaton models showed better fitness in the experimental results, which also explained the mechanisms of compressibility behavior. The extent of the effective percentage addition of recovered TiC as reinforcement in the Al-Mg-Cu-Zn alloy was identified based on the green strength obtained using the diametrical compression test. The best suitable sintering temperature was also determined using thermogravimetric analysis or differential scanning calorimetry and the estimated sinterability index.

Effect of TiC on microstructures and mechanical behaviors of low-density Nb-Ti-Al alloys fabricated by laser solid forming

Ultra-high temperature Nb alloys are prospective for practical applications as aircraft materials. Sufficient efforts must be made to improve their manufacturing technologies and properties. The Nb-Ti-Al alloys with TiC addition were fabricated by laser solid forming (LSF) in this work. LSFed Nb-Ti-Al-TiC alloys which were composed of Nbss and (Nb,Ti)C had excellent formability and metallurgical quality. There were columnar and equiaxed Nbss grains in Nb-37Ti-10Al-3TiC and Nb-37Ti-10Al-5TiC while there were entire equiaxed Nbss grains in Nb-37Ti-10Al-8TiC. Expectant columnar-to-equiaxed transition was realized by the addition of TiC. Moreover, the grain sizes gradually decreased from the addition of 3TiC to 8TiC, and the average grain size of Nb-37Ti-10Al-8TiC decreased to 22.08 μm. The strip-like and particle-like (Nb,Ti)C precipitation coexisted in Nb-37Ti-10Al-3TiC and Nb-37Ti-10Al-5TiC, but only particle-like (Nb,Ti)C formed in Nb-37Ti-10Al-8TiC. The tensile strength, compression strength and fracture toughness of all Nb-Ti-Al-TiC alloys increased with the increase of TiC content. For Nb-37Ti-10Al-8TiC, the maximum tensile strength of 754.14 ± 3.84 MPa, compression strength of 3310.0 ± 55.28 MPa and fracture toughness of 34.96 MPa·m1/2 were obtained. The simultaneous increase of strength and fracture toughness was mainly attributed to fine grain strengthening by TiC addition. Compared with Nb alloy with the addition of Ta, W, Mo and Hf, the LSFed Nb-Ti-Al-TiC alloy had considerably high strength and was of low density. This confirmed the feasibility of preparing Nb alloy by LSF technology and adjusting the microstructure and property.

TiC strengthened CoCrNi medium entropy alloy: Dissolution and precipitation of TiC and its effect on microstructure and performance

In order to improve the strength and corrosion resistance of CoCrNi medium entropy alloy, TiC strengthened CoCrNi medium entropy alloy (CoCrNi/(TiC)x (x=0.1, 0.2, 0.4)) was designed by addition of different amounts of TiC. The effects of TiC content on the microstructure, mechanical properties, and corrosion resistance of the alloy were investigated. It was found that the precipitation morphologies of TiC changed from lamellar eutectic to needle structure with the increase of TiC content, and finally formed mixed needled and bulk TiC particles. TiC appears as a dissolution−precipitation phenomenon in the CoCrNi alloy, which is important for the mechanical properties and corrosion resistance of the CoCrNi/(TiC)x alloy. The strength of alloy was enhanced obviously after the addition of TiC. The compressive yield strength of CoCrNi/(TiC)0.4 alloy reached 746 MPa, much larger than that of the CoCrNi medium entropy alloy, 108 MPa. Additionally, the addition of TiC was found to improve the corrosion resistance of CoCrNi medium entropy alloy in the salt solution.

Microstructure and Mechanical Properties of (Ti, Nb)C Ceramic-Reinforced 316L Stainless Steel Coating by Laser Cladding

The poor wear resistance of 316L stainless steel restricts further practical application. In this study, to improve its microhardness and wear resistance, the TiC and NbC ceramic particles were introduced to 316L powder fabricate (Ti, Nb)C ceramics-reinforced composite coatings by laser cladding. The effects of ceramics addition on the phase composition, microstructure, microhardness, and wear properties of the composite coating were investigated with an X-ray diffractometer, optical microscopy, scanning electron microscopy, a Vickers hardness tester, and a multi-functional surface performance tester. Results indicate that the TiC and NbC ceramic particles were distributed at the grain boundaries, effectively inhibiting the grain growth and refining the microstructure. The addition of ceramic particles could have decreased the temperature gradient and promoted the transformation from columnar crystals to equiaxed crystals. In addition, the microhardness was improved due to fine grain strengthening and solid solution strengthening. The friction coefficient and cross-sectional area of the composite coating were 0.381 and 8164.732 μm2, which was 0.846 and 0.603 times that of the 316L coating, respectively. Moreover, severe adhesive wear and plastic deformation was transformed into slight adhesive wear and abrasive wear due to the addition of TiC and NbC particles. This study provides new approaches to improving the wear resistance of 316L stainless steel and broadens its application.

The Effect of TiC and Zr Additions on the Microstructure and Mechanical Properties of Ti-30Mo Alloy

In this study, Ti-30Mo-nTiC (0, 0.5 wt.%) and Ti-30Mo-0.5TiC-xZr (0, 4, 8, 12 wt.%) alloys were prepared using the powder metallurgy process with the addition of Zr at different rates. The effect of TiC and Zr additions on the microstructure and mechanical properties of the Ti-30Mo alloys were investigated, respectively. The results demonstrated that the addition of 0.5 wt.% TiC significantly improved the density, tensile strength and elastic modulus. The ultimate tensile strength, elongation and elastic modulus of the Ti-30Mo-0.5TiC alloy were determined to be 825 MPa, 7.3% and 112 GPa, respectively. For Ti-30Mo-0.5TiC-xZr alloys, the addition of Zr (8 wt.% or less) results in alloys having a high relative density (&gt;98%), with the density of the alloy decreasing significantly when the Zr content is 12 wt.%. As the Zr content increases, the β phase lattice constant also increases along with the amount of carbide aggregation. This leads to a decrease in the alloy strength, with an increase in the alloy hardness. During high temperature tensile testing at 600 °C, the Ti-30Mo-0.5TiC alloy still had suitable mechanical properties, with its ultimate tensile strength and elongation being 472 MPa and 12.8%, respectively.