Addition Of Ti Research Articles

Enhanced Mechanical Properties Via the Incorporation of Ti in Cu Alloys

The influence of Ti addition on the microstructure, mechanical properties and electrical conductivity of Cu-14Fe alloy is studied. Great emphasis has been laid on the second phase, texture and mechanical properties. No new phase other than α-Fe phase could be found in Cu-14Fe-0.1Ti alloy using XRD and SEM. With 0.1Ti addition, the distribution of α-Fe phase strip is slightly heterogeneous. Cube, s and brass texture components are largely strengthened in Cu matrix with Ti addition, while copper and goss texture components are rare in Cu matrix of both alloys. In α-Fe phases, α fiber and goss texture components are highly strengthened with Ti addition. It is found that enhanced mechanical properties are achieved in Cu-14Fe-0.1Ti alloy. In detail, with Ti addition, the yield strength and ultimate tension strength increase from 538 and 561 MPa to 580 and 583 MPa, respectively, while maintaining a high value of elongation to failure (6.5%). A lower equivalent grain size and a higher KAM value mainly contributes to the higher yield strengthening effect in Cu-14Fe-0.1Ti alloy. The lower equivalent grain size is derived from the small size distribution range and the small size of Cu matrix in Cu-14Fe-0.1Ti alloy. The dissolution of Ti and formation of nano second phases also improve mechanical properties. However, texture hardly plays a role in the strengthening effect. 0.1Ti addition hardly reduces the electrical conductivity of Cu-14Fe alloy, maintaining a value of 33.43% IACS. The results in this work could provide guidance in texture evolution and property evaluation in Cu-Fe alloys.

Effect of Ti addition on the microstructure and corrosion behavior of laser cladding AlCoCrFeNi high-entropy alloy coatings

AlCoCrFeNi high-entropy alloys (HEAs) has higher strength and wear resistance but poorer corrosion resistance. In the present investigation, the AlCoCrFeNi HEAs containing titanium(Ti) were fabricated via laser cladding to enhance the corrosion resistance properties of the coating and the influence of the Ti content on the microstructure of the coatings was investigated. The results show that the microstructure of the coating changed from a single BCC phase to a BCC+B2 phase with the addition of Ti. The Laves phases appeared within the coating when the Ti content was beyond 0.5 mol ratio. As an excellent corrosion-resistant element, Ti promoted the formation of a passive film and enhanced the corrosion resistance of the HEAs coating. The corrosion resistance of the coating first increased and then decreased with the addition of Ti, and the AlCoCrFeNiTi0.5 coating exhibited optimal corrosion resistance.

Improving strength and elongation of laser directed energy deposited Cu-Nb alloy via Ti addition

The Ti element was designed to optimize the Cu/Nb interface structure. The Cu-Nb and Cu-Nb-Ti alloys were successfully prepared by laser directed energy deposition. Results show that the introduction of Ti can change the incoherent Cu/Nb interface into the semi-coherent Cu/β-Cu3Ti/Nb interface. The Cu/Nb interfaces are easily sheared, producing an attractive force on the dislocations, and the dislocations pile up at the incoherent Cu/Nb interfaces. As a consequence, the Cu-Nb deposited alloy exhibits a relatively low total elongation of 7.7 ± 1.1%. Instead, semi-coherent Cu/β-Cu3Ti/Nb interfaces change the movement of dislocations, making it easier for dislocations to transmit across the interface, thus relieving the stress concentration at the interface, which endows the Cu-Nb-Ti deposited alloy the higher total elongation of 13.4 ± 0.2%. In addition, due to the precipitation strengthening and solid solution strengthening, the Cu-Nb-Ti deposited alloy exhibits higher strength of 795 ± 7MPa.

Microstructure and properties of self-propagating high-temperature synthesized (Ti, W)C carbides

Refractory metal carbides play a critical role in numerous applications due to their exceptional hardness, excellent wear resistance and high-temperature stability. This study successfully synthesizes (Ti, W)C powders by using the self-propagating high-temperature synthesis (SHS) method. The results indicate that the phase structure, morphology, microstructure of (Ti, W)C carbides differ significantly from those of WC carbide synthesized using the similar technique. The (Ti, W)C carbides exhibit angular grain morphology with refined grain sizes due to the addition of Ti. Furthermore, the influence of the Ti/W ratio on the nanohardness of (Ti, W)C was examined, with the (Ti0.6, W0.4)C sample achieving the highest hardness of 35.7 GPa ± 2.8 GPa.

High-Temperature Oxidation Study in a Multi-Oxidant Environment Using 18O Tracer

The goal of this study was to use 18O-enriched water to better understand the role of H2O in high-temperature oxidation. Seven model and three commercial M-Cr and M-Cr-Al alloys were studied in air with 10% of H2O at 800 °C for 5 h. Oxygen from water vapor was more reactive than oxygen from the air and 18O enriched at the outermost layers of the formed Cr- and Al-rich oxides. Alloys with Al and/or Ti additions showed signs of internal oxidation but 18O was not enriched inside the alloy in locations with internal oxidation. Depending on the alloy Al content, the oxide went from Al oxidation beneath a chromia scale to external alumina scale formation.

Effects of Ti Addition on Microstructure, Mechanical Properties and Corrosion Resistance of the Cu-Zn-Ni Alloy

Effects of Ti Addition on Microstructure, Mechanical Properties and Corrosion Resistance of the Cu-Zn-Ni Alloy

Effects of Cu and Ti Addition on the Corrosion Characteristics of Super-Duplex Stainless Steel

Effects of Cu and Ti Addition on the Corrosion Characteristics of Super-Duplex Stainless Steel

Effect of SiC particles on microstructure and mechanical properties of SiCp/AZ91 magnesium matrix composite brazed joint

The impact of SiC particles on the microstructure, mechanical properties, and fracture morphology of magnesium alloy brazed joints was investigated. The brazing experiments of AZ91+AZ91, AZ91+SiCp/AZ91, and SiCp/AZ91+SiCp/AZ91 were carried out under the same technological conditions by using the self-designed special filler metal for magnesium matrix composites. The impact of SiC particles on the microstructure and mechanical properties of brazed joints was analyzed. The addition of Ti can effectively enhance the wettability of filler metal on SiC particles. The shear strength of SiCp/AZ91+SiCp/AZ91 joints is 76.0MPa. The shear strength of the joint is 43.4% higher than that of AZ91+ AZ91.

Study on the impact toughness and crack propagation behavior of Ti microalloyed weathering steel laser-MAG hybrid welded joints

In this work, the effect of Ti microalloying on the impact toughness of weathering steel laser-MAG hybrid welded joints was investigated and the corresponding crack initiation and propagation mechanisms were revealed. The results show that the impact toughness of heat affect zone (HAZ) increased by 39.4% and weld metal (WM) by 70.9% compared to Ti-free weathering steel welded joints. The degree of improvement in impact toughness gradually increases with the direction from BM (base metal) to WM. In the WM, Ti element can refine the precipitations and reduce the shape and size of M−A constituents. Furthermore, the microstructure in the WM exhibits the obvious preferred orientations, i.e., the maximum IPF intensity value are concentrated around the [111] pole (the slip direction of BCC structure), which is more prone to slip under external forces. In the HAZ, the addition of Ti mainly plays a role in decreasing the size of precipitations, inducing AF precipitation and increasing the homogeneity of grain size. Therefore, the impact toughness of WM and HAZ for Ti microalloyed weathering steel welded joints is improved by hindering the crack propagation. In addition, in the WM, the main crack path is flatter and the number of secondary cracks is more than that in the HAZ, indicating that the impact toughness of WM is poorer.

Microstructure, mechanical, and magnetic properties of powder metallurgy FeCoNiSi–Cu, FeCoNiSi–Mn, and FeCoNiSi-Ti equiatomic HEAs manufactured by spark plasma sintering

FeCoNiSi–Cu, FeCoNiSi–Mn, and FeCoNiSi–Ti equiatomic high entropy alloys (HEAs) were designed and produced via powder technology using spark plasma sintering (SPS). Metallurgical analysis tools, including SEM, XRD, EBSD, were used to investigate the crystal structure and the distribution of the formed phases for the prepared HEAs. The formation of a ductile FCC phase for all the prepared HEAs was observed, while the brittle BCC phase was formed only for FeCoNiSi–Mn HEA. By comparing the results with thermodynamic parameters, it is found that there is a strong agreement for the results with the valence electron concentration rule. FeCoNiSi–Cu and FeCoNiSi–Mn HEAs show 100% relative density, whereas FeCoNiSi–Ti HEA shows only 95%. All the prepared HEAs with Cu, Mn, and Ti additions show high hardness values of 507, 710, and 495 Hv, respectively. Both FeCoNiSi–Cu and FeCoNiSi–Mn HEAs have high compressive strength and yielding strength of 1854 MPa,1390 MPa for FeCoNiSi–Cu HEA and 1565 MPa, 1482 MPa) for FeCoNiSi–Mn HEA, respectively. Although having finer grains, FeCoNiSi–Ti HEA shows the lowest compressive strength and yield strength values. This is due to the tendency of the alloy to form intermetallic compounds and the presence of pores that act as nuclei for crack initiation and propagation. In addition, due to the presence of non-ferromagnetic elements in equiatomic ratio with other ferromagnetic elements (FeCoNi), FeCoNiSi–Cu HEA shows only 59.4 emu/gm for magnetization saturation, but the magnetic properties for both FeCoNiSi–Mn and FeCoNiSi–Ti HEAs nearly disappeared.The electrical resistivity for all the prepared HEAs is very high.

Influence of Ti addition on the structure, thermal stability of SiTiOC ceramics and pyrolysis behavior of SiTiOC xerogel

Ti doping SiTiOC ceramics were prepared by sol-gel method with tetrabutyl titanate (TBT) as modifier. The thermal stability of SiTiOC ceramics with various Ti contents was studied. Meanwhile, the influence of Ti addition on the pyrolysis behavior of SiTiOC xerogel and the structure evolution of SiTiOC ceramics were investigated. The ceramic yield of SiTiOC xerogels were improved greatly by introducing TBT, while the improvement of ceramic yield had an upper limit, for the simultaneous increase of volatile CH3O(CH2)3OH. At 900 °C pyrolysis, SiTiOC ceramics were amorphous, and Ti existed by oxides. At 1200 °C and 1400 °C pyrolysis, the crystallinity of SiTiOC ceramics increased, TiC phase appeared in ceramics due to the carbothermal reduction of titanium oxides. With increased Ti contents, TiC contents increased in ceramics attributed to the preferentially carbothermal reduction of titanium oxides. The addition of Ti improved the thermal stability of SiOC ceramic system, but such an improvement was sensitive to the Ti contents. 0.05Ti-1400 ceramic exhibited the highest thermal stability with the mass change of 6.51%. Because the oxide scale of 0.05Ti-1400 ceramic was complete and dense, with lowest thermal stress and oxygen diffusion rate for the least TiO2 formed in the oxide scale. Concurrently, the TiO2 particles formed with long rod-like which distributed uniformly in oxide scale that can toughen the oxide scale. While for 0.1Ti-1400 and 0.2Ti-1400 ceramics, the increase of Ti outward diffusion degree damaged the oxide scale and accelerated the oxidation of free carbon.

Improving flexural performance of repaired C/C composites through Ti addition: Mechanism analysis

Ti-doped Ni-based solder was used as the repair agent to recover the flexural performance of the damaged carbon/carbon (C/C) composites. The effects of the contents of Ti on the microstructure, chemical compositions, and flexural strength were investigated. The thermal stress distribution and repair mechanism was studied by finite element analysis methods. The addition of an appropriate amount of Ti enhanced the wetting performance of the repair agent on the surface of C/C composites. Besides, the TiC hard particles formed at the interface provided strengthen effect, and form a gradient structure of coefficient of thermal expansion (CTE), thereby enhancing the interface bonding ability and improving the flexural performance of the repaired C/C composites. The flexural strength was the highest with a recovery rate of 92.6 % when the content of Ti was 5 wt%. This work provides a strategy for the engineering application and improving the damage repair of C/C composites.

Microstructure and mechanical properties of an elevated temperature L12-type Ni-Co-Cr-Al-Ti-V-B-based high-entropy intermetallic

In this study, a novel L12-type Ni46.6Co23.3Cr10Al9Ti6V5B0.1 high-entropy intermetallic (HEI) with the excellent strength-ductility combination at 25 ℃ and 800 ℃ was prepared by vacuum arc melting. An ultrahigh volume fraction of cubical L12-type nanoparticles (∼81 %) was formed uniformly inside the grains after annealing. The intragranular L12 phase, FCC nanolayers, and intergranular blocky FCC precipitations constituted the heterogeneous structure. The annealed HEI exhibits high room-temperature yield strength (∼711 MPa) and ultimate tensile strength (∼937 MPa) with large tensile elongation (∼17 %). The room-temperature plasticity is superior to that of many other simple ordered intermetallics. The yield strength can still be maintained at ∼740 MPa with a total strain of about 6.7 % when tested at 800°C, and its strength is higher than many L12 nanoparticle-strengthened high-entropy alloys. High strength is primarily attributed to the elevated volume fraction of L12 nanoparticles and the significant increase in the antiphase boundary energy caused by the addition of Ti and V elements. The stacking-fault (SF) networks, L-C locks, and K-W locks provide sustained work-hardening capacity, resulting in excellent yield strengths at 25 ℃ and 800 ℃. In addition, the favorable ductility is due to the formation of intragranular disordered FCC nanolayers and grain boundary FCC precipitations, which can avoid premature intergranular fracture.

Microstructure and properties behavior of in situ synthesized with high content (Ti, W) C reinforced In625 by two step-laser direct energy deposition

The formation of sensitive interface cracks and the difficulty in processing high-concentration Ni-based ceramic coatings via direct energy deposition (LDED) present major engineering challenges. To address these, high-quality In625/ceramic coatings with various mass contents of Ti, nickel-coated graphite (Ni3C), and WC were fabricated on QT250 using two-step laser directed energy deposition (TsLDED). The influence of the Ti/C: WC molar mass ratio on the bonding interface, microstructure, phase composition, and mechanical properties of the coatings was analyzed. The results indicated that grains at the In625/ceramic coating interface formed epitaxial growth, ensuring a robust bond. In situ synthesis of (Ti, W) C, WCx (WC and W2C), M23C6, and other precipitated phases were uniformly distributed, enhancing nucleation, refining microstructure, and improving mechanical properties. The addition of Ti facilitated the transformation of WCx to (Ti, W) C. High Ti and C concentrations promoted eutectic structure formation in the matrix phase, enhancing performance. The In625 + 56 % Ti – 14 % Ni3C – 30 % WC composite coating exhibited the highest microhardness and the lowest friction coefficient, with microhardness 5.61 and 3.6 times that of QT250 and In625 coatings, respectively, and a friction coefficient 0.3 times that of In625. Variations in the Ti/C: WC molar mass ratio directly affected the content, proportion, and type of (Ti, W) C, WCx, γ-Ni, and eutectic structures comprising M23C6, NiTix, Ni2W4C, Cr2Ti, and γ-Ni, influencing microstructure evolution and mechanical properties. The TsLDED process thus enables the preparation of In625/ceramic reinforced coatings with improved mechanical properties.

Inhomogeneous distribution of oxides in various 9Cr ODS alloys and their mechanical performance at room temperature and 650 °C

Oxide dispersion strengthened (ODS) steels have been considered as promising structural materials for fusion reactors. In fabricating ODS steels, homogenous distribution of nano-sized oxides is always expected. In this work, Ti and C were respectively added into the 9Cr alloy with 2 wt% Mn, and the effects of individual Ti addition on microstructure and mechanical performance of ODS alloys are studied. Regularly distributed oxides were revealed in the 9Cr alloys fabricated by hot isostatic pressing (HIP), irrespective of alloying compositions, which indicates the strong interaction between oxides and phase interface. Alloying elements within the matrix can be incorporated into these regularly distributed oxides. Oxide nanoparticles will affect the phase transformation behaviors and the microstructure of as-HIPed 9Cr alloys without oxides is different from that of 9Cr ODS alloys. By performing post-HIP heat treatments, the matrix conditions of 9Cr ODS alloys can be adjusted, and ferritic and martensitic 9Cr ODS alloys are respectively obtained. With tensile tests at room temperature and 650 °C, effects of oxides and matrix conditions on 9Cr alloys were evaluated. It is found that individual Ti addition has a softening effect on the 9Cr alloys, despite that whether oxides are added. Simultaneous addition of Ti and C can improve the strength of 9Cr alloys evidently. Poor ductility at 650 °C is a critical issue for 9Cr ODS alloys, while the 9Cr alloys without oxides have favorable combination of strength and ductility at both room temperature and 650 °C.

Effect of Nb and Ti additions on microstructure, hardness and wear properties of AlCoCrFeNi high-entropy alloy

The use of Nb and Ti in the development of high-performance alloys is strategically important for technological advancement. The effect of Nb and Ti additions on the microstructure, hardness and tribological properties of the High Entropy Alloy (HEA) AlCoCrFeNi was evaluated. The addition of 0.6 mol of Nb led to the formation of Laves phase, resulting in a B2/Laves type hypoeutectic microstructure. Conversely, increasing Ti concentration led to the formation of a dendritic microstructure, with interdendritic region composed of Cr-rich BCC-A2 and Fe-Ti rich Laves phase. The average hardness values obtained were 790 HV, 597 HV and 731 HV for AlCoCrFeNiNb0.6, AlCoCrFeNiTi0.5 and AlCoCrFeNiTi1.2 HEAs, respectively. The high hardness was attributed to the formation of the Laves phase and Cr-rich phases, in addition to solid solution hardening, as confirmed by the increase in the lattice parameter calculated by Rietveld refinement method for both B2 and BCC-A2 phases. While the three compositions exhibited comparable friction coefficient, the alloy containing Nb showed superior wear behavior. This was evidenced by the lower volume of material loss and the lower wear rate, which can be attributed to the fine and homogeneous hypoeutectic microstructure observed in the ingot’s cross section. The wear mechanisms were studied, characteristics features of abrasion and adhesion wear were observed.

Relations of magnetic and electrochemical anti-corrosion properties of (Zr, Ti)-doped NdCeFeB magnets with Ti content

Zr and Ti were co-doped into NdCeFeB sintered magnets to improve the magnetic and electrochemical anti-corrosion properties. Both performance are found closely associated with Ti content. At 0.15 wt%Ti, the sample shows higher coercivity without energy product loss compared to the Ti-free sample and other Ti additions, due to the matrix-phases refinement and optimized distribution of RE-rich phases. For this sample, its corrosion current density and charge transfer resistance are 1.94 μA/cm2 and 1734 Ω•cm2 in NaCl solution respectively, which exhibits obviously improved corrosion resistance in comparison with the Ti-free magnet. The charge transfer resistance has been increased by 45.6 %. The apparently improved corrosion resistance is mainly attributed to the decreased amount of active reaction channels and the enhanced protective effect of TiO2, arising from the increment of Ti-rich precipitates. When the content of Ti dopant exceeds 0.5 wt%, the beneficial effects of Ti are overshadowed by the harmful effect of the density reduction on anti-corrosion performance, and the charge transfer resistance decreased with further increasing the dopant content. The new findings provide a theoretical basis for improving physicochemical properties of NdCeFeB magnet.

Analyzing the Influence of Titanium Content in 5087 Aluminum Filler Wires on Metal Inert Gas Welding Joints of AA5083 Alloy

As the demand for lightweight structures in the transportation industry continues to rise, AA5083 aluminum alloy has become increasingly prominent due to its superior corrosion resistance and weldability. To facilitate the production of high-quality, intricate AA5083 components, 5087 aluminum filler wire is commonly utilized in metal inert gas (MIG) welding processes for industrial applications. The optimization of filler wire composition is critical to enhancing the mechanical properties of AA5083 MIG-welded joints. This study investigates the effects of modifying 5087 aluminum filler wires with different titanium (Ti) contents on the microstructure and weldability of AA5083 alloy plates using MIG welding. The influence of Ti contents was systematically analyzed through comprehensive characterization techniques. The findings reveal that the constitutional supercooling induced by the Ti element and the formation of Al3Ti facilitate the heterogeneous nucleation of α(Al), thereby promoting grain refinement. When the Ti content of 5087 filler wire is 0.1 wt.%, the grain size of the weld center was 78.48 μm. This microstructural enhancement results in the improved ductility of the AA5083 MIG-welded joints, with a maximum elongation of 16.64% achieved at 0.1 wt.% Ti addition. The hardness of the joints was the lowest in the weld center zone. This study provides critical insights into the role of Ti content in MIG welding and contributes to the advancement of high-performance filler wire formulations.

The microstructure and mechanical property of W-TiC/Ti composites via chemical-mechanical milling method

Carbide dispersion strengthened W(CDS-W) has attracted much attention as a plasma-facing material (PFM). However, the carbide tends to segregate at W grain boundaries and has poor interface properties with W due to the large difference in the bond structure. In this work, nanometer Ti was added to improve the performance of the W/TiC interface, and nanoscaled W-TiC-x%Ti (x = 0.1,0.5 and 1.0) composites were prepared by chemical-mechanical milling and ordinary sintering method. The effects of Ti on powder morphology, phase composition, microstructure and mechanical properties were systematically investigated using XRD, SEM, EDS, TEM and HADDF technologies. Simultaneously, the existence form and distribution of Ti elements, and W/TiC interface characteristics of powders and composites were analyzed. Moreover, the microstructure evolution and strengthening mechanism were preliminarily discussed. Results show that the W-TiC/Ti powder has an obvious core-shell multilayer structure with a particle size range of 50–120 nm. The addition of Ti exists in the forms of TiC, Ti, and TiO2, and has no effect on the morphology and phase composition. Besides, the phase transformation and solution-precipitation of the Ti-added occurs during the sintering process. Part of Ti precipitates on the W/TiC surface to form Ti rich region, which significantly promotes the dispersion of TiC and improves the W/TiC interface, as well as prevents the growth of W grains, and the average grain size is 2.90 μm. Moreover, the orientation relationship of [013](2‾ 00)TiCFCC||[1‾ 13](1‾1‾ 0)WBCC exists at the W/TiC interface, especially the coherent phase interface is formed. The tensile strength and microhardness at room temperature are 520 MPa and 850 HV0.2, respectively, which is attributed to the synergistic effect of fine-grained strengthening, dispersion strengthening and interface strengthening. This work can provide a new strategy and direction for preparing high-performance CDS-W materials.

Mechanical Properties, Microstructure, Degradation Behavior, and Biocompatibility of Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg Guided Bone Regeneration Barrier Membranes Prepared Using a Powder Metallurgy Method.

Pure zinc exhibits low mechanical properties, making it unsuitable for use in guided bone regeneration (GBR) membranes. The present study focused on the preparation of Zn alloy GBR films using powder metallurgy, resulting in Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg alloy GBR films. The tensile strength of the pure Zn GBR film measured 85.9 MPa, while an elongation at break was 13.5%. In contrast, Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg alloy GBR films demonstrated significantly higher tensile strengths of 145.3 and 164.4 MPa, respectively, whereas elongations at break were 30.2% and 19.3%. The addition of Ti, Fe, and Mg substantially enhanced the mechanical properties of the zinc alloys. Corrosion analysis revealed that Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg alloy GBR membranes exhibited corrosion potentials of -1.298 and -1.316 V, respectively, with corresponding corrosion current densities of 12.11 and 13.32 μA/cm2. These values were translated to corrosion rates of 0.181 and 0.199 mm/year, indicating faster corrosion rates compared to pure Zn GBR membranes, which displayed a corrosion rate of 0.108 mm/year. Notably, both Zn-based alloy GBR membranes demonstrated excellent cytocompatibility, with a cytotoxicity rating of 0-1 in 25% leachate. Additionally, these membranes exhibited favorable osteogenic ability, as evidenced by the quantitative bone volume/tissue volume ratios (BV/TV) of new bone formation, which reached 30.3 ± 1.4% and 65.5 ± 1.8% for the Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg alloy GBR membranes, respectively, after 12 weeks of implantation. These results highlighted the significant potential for facilitating new bone growth. The proposed Zn-0.5Ti-0.5Fe and Zn-0.5Ti-0.5Mg alloy GBR membranes showed promise as viable biodegradable materials for future clinical studies.