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The ability to enhance mechanical and oxidation properties for severe environmental applications has led to substantial academic interest in multiphase ultra-high temperature ceramics (UHTC). The purpose of this work is to study the in-situ solid solution formation of (Zr,Ti)B2 from ZrB2 and TiO2 in a ZrB2-SiC composite using hot pressing reaction sintering. For this, a mixture of 10, 20, and 30 % vol% SiC with ZrB2 was mixed with 2.0 wt% TiO2. Hot pressing sintering was performed with a load of 20 MPa at a final temperature of 1850 °C/30 min in an argon atmosphere. The microstructures, crystalline phases, densities, mechanical properties, and oxidation resistance of the composites were examined and compared with ZrB2-SiC samples lacking TiO2. In samples where TiO2 was added, the matrix grain size slightly decreased, the fracture mode was mainly intergranular, and the SiC grain morphology changed the aspect ratio to be more equiaxed. The solid solution (Zr,Ti)B2 was produced, and it was demonstrated by EDS elemental map images and the XRD analysis that Ti atoms incorporate into the ZrB2 crystalline structure. The development of solid solutions showed no impact on relative densities or Vickers hardness. However, the solid solution formation favored an improvement in fracture toughness, probably owing to the smaller matrix grain size and intergranular fracture mode. Samples exhibiting (Zr,Ti)B2 formation presented lower oxidation resistance than undoped samples in the same oxidizing condition.

Al–Si-based alloys are widely used in the automobile and aerospace industries, whereas high entropy alloys have emerged with many attractive properties. In this study, AlCoCrFeNi high entropy alloy (HEA) is employed to improve the properties of AlSi10Mg alloy through a metal matrix composite approach. Metal matrix composite powder mixture was sintered at 500°C using a hot press at a pressure of 50 MPa. HEA phase was found to be distributed uniformly. An increase of 20 and 40% in hardness and compressive strength were observed by reinforcing HEA in AlSi10Mg alloy. [ABSTRACT FROM AUTHOR]

Traditional studies on boride cermet have rarely considered the effects of the synergistic interactions among their multiple components on their microstructure and properties. In this study, FeCrNiCo-boride cermet is prepared for the first time via hot-press sintering. The microstructure evolution and corrosion resistance of the cermet are investigated for sintering temperatures in the range of 1000–1300 °C. The results show that the phase comprises Mo 2 FeB 2 , MoB 2 , and FCC phases (including that of FeCrNiCo or various intermetallic solid solutions formed by FeCrNiCo decomposition). Owing to its low Gibbs free energy, Mo 2 FeB 2 occurs in the hard phase. Cr atoms dissolve into the crystal lattice and stabilise the Mo 2 FeB 2 crystals. A certain amount of MoB 2 is also present in the hard phase. The bond phase is formed by alloying elements and solid solutions. The cermet sintered at 1100 °C exhibits the least structural defects, highest cermet content, and best corrosion resistance; the porosity is 9.94 % and phase ratio of cermet is 48.9 %. The cermet phase has the smallest grain size of 5.96 μm. The equilibrium potential (E corr) is −0.52 V, corrosion current density (I corr) is 2.07 × 10−6 A/cm2, and open-circuit potential (OCP) in a 3.5 % NaCl solution is −0.34 V. [ABSTRACT FROM AUTHOR]

Boron carbide (B4C) is an essential material in various high-performance applications due to its light weight and hardness. In this work, B4C-based composites were fabricated via a powder route consisting of powder mixing, precursor preparation, and hot-pressing under vacuum. The composites' mechanical properties and microstructure were analyzed to investigate the effect of adding minor second-phase particles. In addition to homogenizing the grain size, the addition of SiC (≤10 wt%) to B4C increased its strength and improved its fracture toughness, with values reaching 551 MPa and 3.22 MPa m1/2, respectively. Meanwhile, the addition of TiB2 (≤10 wt%) significantly improved the strength and fracture toughness only, with values reaching 548 MPa and 3.92 MPa m1/2, respectively, with only a minimal decrease in hardness. Microstructural analysis revealed that the second-phase particles were uniformly distributed and reduced the average grain size, contributing to the increase in strength. Additionally, the TiB2 particles impeded crack propagation and induced crack deflection at the interface, indicating the formation of an intergranular fracture mode. On the contrary, the addition of SiC primarily resulted in transgranular fracture behavior, though it still improved the toughness of the B4C. These results suggest that small amounts of SiC and TiB2 can effectively enhance the mechanical properties of B4C ceramics while maintaining the lightweight characteristics critical for military and aerospace applications. [ABSTRACT FROM AUTHOR]

Scanning Electron Microscope (SEM) is a crucial tool for studying microstructures of ceramic materials. However, the current practice heavily relies on manual efforts to extract porosity from SEM images. To address this issue, we propose PSTNet (Pyramid Segmentation Transformer Net) for grain and pore segmentation in SEM images, which merges multi-scale feature maps through operations like recombination and upsampling to predict and generate segmentation maps. These maps are used to predict the corresponding porosity at ceramic grain boundaries. To increase segmentation accuracy and minimize loss, we employ several strategies. (1) We train the micro-pore detection and segmentation model using publicly available Al2O3 and custom Y2O3 ceramic SEM images. We calculate the pixel percentage of segmented pores in SEM images to determine the surface porosity at the corresponding locations. (2) Utilizing high-temperature hot pressing sintering, we prepared and captured scanning electron microscope images of Y2O3 ceramics, with which a Y2O3 ceramic dataset was constructed through preprocessing and annotation. (3) We employed segmentation penalty cross-entropy loss, smooth L1 loss, and structural similarity (SSIM) loss as the constituent terms of a joint loss function. The segmentation penalty cross-entropy loss helps suppress segmentation loss bias, smooth L1 loss is utilized to reduce noise in images, and incorporating structural similarity into the loss function computation guides the model to better learn structural features of images, significantly improving the accuracy and robustness of semantic segmentation. (4) In the decoder stage, we utilized an improved version of the multi-head attention mechanism (MHA) for feature fusion, leading to a significant enhancement in model performance. Our model training is based on publicly available laser-sintered Al2O3 ceramic datasets and self-made high-temperature hot-pressed sintered Y2O3 ceramic datasets, and validation has been completed. Our Pix Acc score improves over the baseline by 12.2%, 86.52 vs. 76.01, and the mIoU score improves from by 25.5%, 69.10 vs. 51.49. The average relative errors on datasets Y2O3 and Al2O3 were 6.9% and 6.36%, respectively. [ABSTRACT FROM AUTHOR]

The anisotropic material behavior of continuous-fiber-reinforced composites that is evident in their mechanical properties should also be considered in their processing. An important step in the processing of thermoplastic unidirectional (UD) fiber-reinforced tapes is consolidation, where a layup consisting of locally welded UD tape layers is firmly bonded. Compression of the molten thermoplastic matrix material during consolidation leads to a squeeze flow, the direction of which is determined by the fibers. This work presents a model that describes the influence of fiber direction on compression and flow behavior, implemented in the computational fluid dynamics (CFD) software tool OpenFOAM®. To validate the simulation results, we performed experiments in a laboratory consolidation unit, capturing the squeeze flow with cameras and then quantifying it by gray-scale analysis. The specimens used were UD polycarbonate tapes (44% carbon fibers by volume) of various sizes and with various fiber directions. The simulation allows prediction of the changes in specimen geometry during consolidation and is a first step towards optimizing the process by avoiding extensive squeeze flow. [ABSTRACT FROM AUTHOR]

In this study, wet ball milling and hot press methods were used to prepare nanocomposite from ultra-high molecular weight polyethylene (UHMWPE) as a matrix, and modified multi wall carbon nanotubes (MWCNTs) as reinforcement nano-additives. Two batches of MWCNTs were used (Pristine-MWCNTs-B1, and Pristine-MWCNTs-B2). First, the MWCNTs were oxidized (oxide-MWCNTs) by wet chemistry using strong acids, then further functionalized with an amide group (A-MWCNTs). Fourier-transform infrared spectroscopy (FTIR), and Thermal gravimetric analysis (TGA) results confirm the functionalization of the MWCNT with the amide group. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the surface morphology and crystalline behavior of MWCNT after functionalization. Ball milling was used to mix the UHMWPE with pristine MWCNT (1.5% wt), Oxide-MWCNT (1.5% wt), and A-MWCNTs (0.5–2% wt). Then, hot press melting was used to prepare the nanocomposite sheets. Fourier transform infrared spectroscopy (FTIR) confirmed the impact of the balls milling process with time factor on UHMWPE crystallinity and the interaction of the functionalization MWCNT with the UHMWPE matrix. The structure (crystallinity, crystal size) was validated using X-ray diffraction (XRD) patterns. Thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC), and universal testing machine (UTM) were utilized to analyze the structural, thermal, and mechanical properties of the nanocomposites, respectively. The results showed that UHMWPE crystallinity increased after 2 h of ball milling, while crystallinity decreased when pristine-MWCNT, oxide-MWCNTs, and A-MWCNTs (0.5–2 wt%) were added without affecting the crystal structure of UHMWPE. The results showed that adding 1.5 wt% A-MWCNTs-(B1, B2)/UHMWPE increased thermal stability by 16 °C and elongation at the break by up to 74% when used 1.5 wt% A-MWCNT-B1 and 2 wt% A-MWCNT-B2. This shows that the ball milling methods and amide group improved the dispersion and interface interaction between MWCNTs and UHMWPE matrix. [ABSTRACT FROM AUTHOR]

In this paper, the effect of the laser-ablated pattern designs on the bonding performance of single-lap dissimilar joints between Polyamide 6 (PA6) composite reinforced with 15% short glass fibers (PA6-15GF) and 7075 aluminium (Al) alloy in O-temper condition, manufactured through hot-pressing technique, is studied by tensile-shear testing. From the optical microscopy (OM) and scanning electron microscopy (SEM) observations, it is found that laser ablation can create a favorable surface morphology for the adhesiveless joints. This is proved by obtaining a significant improvement in the lap-shear strength of the treated samples which can be up to 36%. According to the X-ray photoelectron spectroscopy (XPS) results, the surface chemistry is altered by generating an active oxide layer which is a more suitable condition for the PA6-Al direct bonding. Moreover, achieving favourable surface characteristics is shown by the static contact angle (SCA) findings with the acquired increase in surface wettability after the laser ablation. It is observed that the SCA can be decreased from 83 ± 2 (for as-received Al) by approximately more than 65%. The results gained from the experiments demonstrate that the shape of the laser-induced surface pretreatment markedly affects the strength of metal/composite single-lap joints (SLJs). [ABSTRACT FROM AUTHOR]

Unidirectional fiber‐reinforced composite laminates have limited resistance to out‐of‐plane impact and are prone to structural integrity damage during service due to low‐velocity impact (LVI). In this study, the hot‐press fusion method was employed to repair the impact‐damaged unidirectional carbon fiber‐reinforced poly‐ether‐ether‐ketone (CF/PEEK) thermoplastic composites. No delamination or matrix cracking induced by impact was observed in the repaired specimens, as confirmed by ultrasonic scanning and digital microscope. In addition, the hot pressing treatment enables the fibers to be covered again by the resin matrix, which eliminates fiber pull‐out and fiber/matrix debonding. Afterward, typical responses of CF/PEEK composite laminates to re‐impact and post‐repair compression are presented in a comprehensive and detailed manner, and compared with the initial impact response and compression after impact (CAI) behavior. The effects of three impact energies and two stacking sequences are considered. The results indicate that quasi‐isotropic laminates are more susceptible to localized fracture damage upon re‐impact as the impact energy increases, due to initial fiber breakage, compared to orthotropic laminates. The hot‐press treatment enhances the compression residual strength of the specimen by 20%–30% compared to its state before repair. These studies offer technical insights into the application of the hot‐press fusion method to enhance the mechanical properties of composite laminates post impact damage. [ABSTRACT FROM AUTHOR]

In this study, Its the influence of according to press, particleboards produced in two different press types which were multiday and continuous hot press, the thickness, density, bending strength, modulus of elasticity, internal bond, surface soundness, withdrawal of screw resistance, moisture, thickness swelling, water absorption, formaldehyde emission content were researched. 18 mm x 2100 mm x 2800 mm size particleboards were manufactured on the production line which was using urea-formaldehyde (F:U;1,07 moles), and 30 % pine, 40 % oak, 20 % beech and 10 % poplar waste mixture of the wood materials. According to results of the tests performed after the multiday and continuous hot press production of the boards; thickness (0,63 %), bending strength (1,27 %), moisture content (0,47 %), thickness swelling (37 %), and water absorption (39,9 %), modulus of elasticity (11,35 %), internal bond (7,22 %) were increased according to multiday hot press while density (2,7 %), surface soundness (18,81 %), withdrawal of screw resistance (14 %) and formaldehyde (57,12 %) decreased. Formaldehyde content, surface soundness, withdrawal of screw resistance are the most prominent properties influenced by continuous hot press. [ABSTRACT FROM AUTHOR]

Nb-Si based ultrahigh-temperature alloys with the composition of Nb-22Ti-15Si-5Cr-3Al (atomic percentage, at. %) were prepared by hot press sintering (HPS) at 1250, 1350, 1400, 1450 and 1500 °C. The effects of HPS temperatures on the microstructure, room temperature fracture toughness, hardness and isothermal oxidation behavior of the alloys were investigated. The results showed that the microstructures of the alloys prepared by HPS at different temperatures were composed of Nbss, βTiss and γ(Nb,X)5Si3 phases. When the HPS temperature was 1450 °C, the microstructure was fine and nearly equiaxed. When the HPS temperature was lower than 1450 °C, the supersaturated Nbss with insufficient diffusion reaction still existed. When the HPS temperature exceeded 1450 °C, the microstructure coarsened obviously. Both the room temperature fracture toughness and Vickers hardness of the alloys prepared by HPS at 1450 °C were the highest. The alloy prepared by HPS at 1450 °C exhibited the lowest mass gain upon oxidation at 1250 °C for 20 h. The oxide film was mainly composed of Nb2O5, TiNb2O7, TiO2 and a small amount of amorphous silicate. The formation mechanism of oxide film is concluded as follows: TiO2 forms by the preferential reaction of βTiss and O in the alloy; after that, a stable oxide film composed of TiO2 and Nb2O5 forms; then, TiNb2O7 is formed by the reaction of TiO2 and Nb2O5. [ABSTRACT FROM AUTHOR]

The hot press bend process of the 5A06 aluminum alloy high-stiffener integral panels was studied by FEM simulations and experiments. The high-temperature deformation behaviors and microstructures were tested by the high-temperature uniaxial tensile tests and the electron backscatter diffraction (EBSD), respectively. A set of physically-based constitutive equations and its VUMAT user subroutine, including dislocation density, grain size, and deformation damage, were established. The effects of forming parameters and blank size on the forming quality of the high-stiffener integral panel were studied. The main typical defects were the surface groove, side face curvature and inclination, springback, and wrinkle of the stiffener. The high-stiffener integral panels should be bent above 350 °C and kept for more than 20 min under a pressure of 8 MPa. [ABSTRACT FROM AUTHOR]

Even though BiFeO3–BaTiO3 (BF–BT) with high Curie temperature and excellent piezoelectric properties is very suitable for high‐temperature applications, its rapid reduction in resistivity with temperature limits its further application. So far, there is no effective method to improve the resistivity of BF–BT at a high‐temperature state. In this work, hot‐press sintering combined with an oxygen atmosphere was used to prepare (1 − x)BF–xBT (x = 0.2–0.33) ceramics for the first time, which reduced the sintering temperature from 1000 to 920°C. The controllable grain size can be achieved by adjusting the sintering temperature and the applied pressure. The X‐ray photoelectron spectroscopy results confirmed that using hot‐press sintering effectively avoided the generation of heterovalent Fe ions, and the resistivity of BF–BT ceramics at the high‐temperature stage was improved by two orders of magnitude. It was found that hot‐press sintering can cause the oriented growth of the sample along the (1 1 0) direction, and further refined X‐ray diffraction was used to accurately analyze the changes in the lattice structure. The hot‐press sintered samples obtained larger polarization strength, especially the electro‐induced strain showed excellent temperature stability in the wide temperature range of 30–170°C. Hot‐pressing sintering combined with an oxygen atmosphere is more suitable for preparing high insulation and electrical breakdown resistance ceramics. [ABSTRACT FROM AUTHOR]

Mn, Si in high-strength automotive steels caused intergranular oxidation during hot-rolled coiling, which decreased pickling efficiency and caused surface cracking in the subsequent cold rolling. In current study, the sealed tube heating and soaking was used to simulate the hot rolled coiling. The external oxide layer transformation and intergranular oxidation mechanisms of 2000 MPa hot press hardening steel with different hot rolled coiling temperatures were studied, as well as the effect of micro-additions of Sb element on the internal oxidation. The results showed that when the coiling temperature was higher than 570 °C, the ambient oxygen pressure would decrease below the dissociative oxygen pressure of FeO due to the decarburization reaction and selective oxidation of Mn and Si, thus the FeO in the external oxide layer dissociates to form Fe2+ and O2−. Then Fe2+ combined with each other forming a layer of metallic iron on the surface of the external oxide layer, and O2− diffused inwards as the oxygen source of the internal oxidation. Adding minor tramp element Sb in experimental steel can inhibit intergranular oxidation during hot rolled coiling. The intergranular oxidation depth would decrease with the increase of Sb content. • Simulation of coiling oxidation environment by Sealing tube heating and soaking. • The coiling oxidation mechanism of 2000 MPa hot press hardening steel was studied. • Sb can inhibit intergranular oxidation of 2000 MPa hot press hardening steel. [ABSTRACT FROM AUTHOR]

The frictional properties between the continuous hot pressing machine board, steel strip, steel strip, and hot press plate, as well as steel strip and sealing strip, were investigated in this paper. Friction coefficient tests were conducted using a friction coefficient tester to determine the friction coefficients between wood materials and polyethylene plastic, steel strip, polytetrafluoroethylene, polyethylene engineering plastic, and steel strip. Factors influencing the friction coefficients of various friction pairs were analyzed with the aim of providing reference for the design and manufacturing of the continuous hot press for laminating artificial boards with pressure air-float veneers. The experimental results indicated that the static friction coefficient between polytetrafluoroethylene and steel at room temperature was 0.10, and the dynamic friction coefficient was 0.01. The static friction coefficient between polytetrafluoroethylene plate and steel plate decreased initially and then increased with the increasing of temperature, while the dynamic friction coefficient continued to increase. In the direction perpendicular to the wood grain, the static friction coefficient was maximum when moving along the polyethylene plastic film, with the value of 0.62. In the friction pair of artificial board and polyethylene plastic, the static friction coefficient of mediumdensity fiberboard ranged between 0.61 and 0.69, while that of particleboard ranged between 0.56 and 0.71. [ABSTRACT FROM AUTHOR]

In the study, the bonding strength of phenol-formaldehyde (PF) adhesive on plywood under different hot press temperature and time was evaluated. A mechanical mathematical model was established to analyze the curing process of PF adhesive, in which the parameters of model could be used to predict the bonding strength and change rate of plywood. The thermal curing degree of the adhesive was determined by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) as well as Nuclear magnetic resonance (NMR) were used to analyze the chemical structure of adhesives with different curing degree. The results show that higher of hot press temperature, the shorter of time to reach the target temperature. The changed rate constant of bonding strength and the maximum bonding strength of plywood could be calculated by the mechanical mathematical model accurately, and the temperature at 130°C was the optimal temperature for plywood manufacture in the study. FTIR analysis indicated that the primary reaction of PF adhesive in the alkaline medium was the condensation occurring between hydroxymethyl groups and residual active position of other phenolic rings. NMR data presented that the ratio of -CH2- (34.5–35.1 ppm)/CH2-OH (62.4–63.1 ppm) could be used to evaluate the curing degree of PF adhesive. [ABSTRACT FROM AUTHOR]

In this paper, BNNSs/Al 2 O 3 composite powder was prepared by in-situ reaction using borate nitridation method and BNNSs/Al 2 O 3 composite ceramics were prepared by hot-pressing sintering. This method achieves uniform mixing of BNNSs and Al 2 O 3 ceramic matrix and reduces the introduction of impurities in the processing process. The BNNSs/Al 2 O 3 composite ceramics have excellent bending strength (549.4 MPa), fracture toughness (5.18 MPa m1/2) and hardness (21.3 GPa). The high hardness of composite ceramics is attributed to high grain boundary strength and density. The reinforcing mechanisms of ceramics include BNNSs pull-out, BNNSs bridging, crack deflection as well as the transgranular fracture and intergranular fracture of Al 2 O 3 matrix. [ABSTRACT FROM AUTHOR]

In this research, the silk web was hot-pressed for various times, the effect of press time on the structure and mechanical properties of silk non-woven fabric was also investigated. The yellowing appeared in the silk non-woven fabric and became more apparent as press time was increased. The crystallinity of silk was decreased by the hot press treatment and it did not change significantly with an increase of hot press time. The porosity of silk non-woven fabric was constantly decreased until 120 s and it did not change much after that. The thickness of silk non-woven fabric was significantly decreased by a press time of 10 s and slightly decreased with a further increase of hot press time. The hot press treatment increased the maximum stress and elongation of silk non-woven fabrics. The press time had a significant impact on the mechanical properties of silk non-woven fabric, with 90 s being the optimum condition for the best work of rupture of silk non-woven fabric. [ABSTRACT FROM AUTHOR]

Impact by hailstone, volcanic rock, bird strike, or also dropping tools can cause damage to aircraft materials. For maximum safety, the goal is to increase Charpy impact strength (auc) of a carbon-fiber-reinforced thermoplastic polyphenylene sulfide polymer (CFRTP-PPS) composite for potential application to commercial aircraft parts. The layup was three cross-weave CF plies alternating between four PPS plies, [PPS-CF-PPS-CF-PPS-CF-PPS], designated [PPS]4[CF]3. To strengthen, a new process for CFRP-PPS was employed applying homogeneous low voltage electron beam irradiation (HLEBI) to both sides of PPS plies prior to lamination assembly with untreated CF, followed by hot press under 4.0 MPa at 573 K for 8 min. Experimental results showed a 5 kGy HLEBI dose was at or near optimum, increasing auc at each accumulative probability, Pf. Optical microscopy of 5 kGy sample showed a reduction in main crack width with significantly reduced CF separation and pull-out; while, scanning electron microscopy (SEM) and electron dispersive X-ray (EDS) mapping showed PPS adhering to CF. Electron spin resonance (ESR) of a 5 kGy sample indicated lengthening of PPS chains as evidenced by a reduction in dangling bond peak. It Is assumed that 5 kGy HLEBI creates strong bonds at the interface while strengthening the PPS bulk. A model is proposed to illustrate the possible strengthening mechanism. [ABSTRACT FROM AUTHOR]

An isotactic polypropylene/aluminum alloy hybrid was fabricated by a self-made ultrasonic-assisted hot press molding (UAHPM) technology, and the properties and structure at the plastic-metal interface were explored. The surface of aluminum alloy was chemically etched and anodized to form micro- and nano- pore structures. The field emission scanning electron microscopy (FE-SEM) was used to observe the strong micro-nano two-scale mechanical interlocking structures formed at the interface of PP/aluminum hybrid. The element diffusion at the plastic-metal interface was detected by the energy dispersive spectrum. The results showed the stronger isotactic polypropylene/aluminum hybrids were manufactured by the UAHPM technology compared with the traditional press-molded samples. The maximal tensile shear strength of the UAHPMed hybrid reached up to 18.96 MPa, compared with 9.77 MPa for the conventional hybrid. The bonding layer between isotactic polypropylene and the aluminum alloy was 3.7um prepared by the UAHPM technique against 6.2 um for the conventional press molding technology. The thermal property of polypropylene was examined by differential scanning calorimetry (DSC), and crystal structure was characterized by X-ray diffraction (XRD), and the β-crystal of PP existence at the PMH's interface contributes to the excellent plasticity and strong bonding strength. [ABSTRACT FROM AUTHOR]

Nanocellulose (NC) has been spotlighted as a new building block of future materials since it has many advantages, such as being lightweight and environment-friendly and having high mechanical properties and heat resistance. However, the use of NC requires an upscale manufacturing process to maintain its advantageous properties. Herein, the process of assembling NC into a macro-scale bulk material was developed through a combination of steam treatment and hot press molding. The steam treatment was applied to an NC paste to energize the hydroxyl groups in the cellulose, followed by two stages of hot press molding, which helped in the self-assembly of NC without adhesives. Cellulose nanocrystals were used as the NC, and circular disk shape specimens were prepared. The mechanical properties of the prepared bulk material were higher than typical engineering plastics. In addition, an end mill machining test of the NC bulk material showed its machinability. This paper showed the processing feasibility of NC bulk material, which can substitute plastics.

Bi 4 Ti 3 O 12 (BIT) ceramic has great potential in high-temperature environment due to its high Curie temperature T C ~ 675 °C. In this work, hot press sintering (HPS) is applied on the 0.01 mol Ce and Nb/Cr co-doped BIT (BCTNC) ceramics to enhancing the low piezoelectric coefficient (d 33 < 7 pC/N) and resistivity. Extremely high d 33 (~39 pC/N) together with high T C (~672 °C) and high dc resistivity ρ (~1.49 ×107 Ω ∙cm at 500 °C) are obtained in HPS samples. The enhancement of piezoelectricity benefits from high density of domain and high poling electric field. Moreover, outstanding thermal stability of piezoelectric constant (d 33 ~ 35 pC/N after annealing at 650 °C) and low dielectric loss (tan δ ~ 3.8% at 500 °C) are observed as well. These findings are instrumental in understanding HPS and provide a possible manipulation of crystallized mechanism and domains growing kinetics to enhance piezoelectric performances of BIT based ceramics. [ABSTRACT FROM AUTHOR]

This study was carried out to improve the surface of the AA7075 alloy, which does not resist wear. Therefore Al–SiC composite layer on the surface of AA 7075 material was coated with Al+5vol.%SiC powders under 600°C and 100, 120, 140 MPa pressure by the hot pressing sintering method. The microstructure of the transition zone between the coating and the substrate material was analyzed by using optical microscopy (OM), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM) techniques. In addition, XRD measurement and microhardness of the coating layer were obtained. Coating surface was also subject to linear reciprocating wear test and coefficient of friction (COF), wear volume, and mass loss were detected. The results have shown that micro-pores between Al and SiC powders reduced by increasing the pressing pressure. However, although there was a reduction in wear volume and mass loss, microhardness values dramatically increased. Wear test was modeled in ANSYS 2021 R2 package program depending on Archard's law and numerical analysis was conducted. As a result of the experimental results and numerical analysis, the volume loss values occurring in the coating area were found to be compatible with each other. [ABSTRACT FROM AUTHOR]

By regulating preheating time, effects of water/moisture immigration and distribution in wood on sandwich compression formation were investigated in this study. Kiln-dried poplar wood was first immersed in water to result in high moisture content (MC) layers on wood surfaces. These wood specimens were then conditioned at room temperature in sealed plastic bags and preheated with hot press platens at 180 °C to drive water/moisture into wood. Wood preheated for 10–600 s contained one to two high MC layers all the time. Extended preheating time moved the high MC layers from wood surfaces to the center. Mechanical pressure on preheated wood specimens resulted in sandwich compressed wood with the compressed layer(s) position(s) consistent to that of the high MC layer(s) before compression. The positions of compressed layer(s) and MC peak(s) both increased exponentially as a function of the logarithm of preheating time. Wood preheating by platens led to water/moisture migration and therefore controlled water/moisture distribution, thus promoting the softening of specific wood layer(s), which is mainly responsible for sandwich compression. A logarithmical model that can be used for predicting the position(s) of the compressed layer(s) was developed. [ABSTRACT FROM AUTHOR]

The prevalent issue of poor ductility in titanium matrix composites severely restricts the development and application of these materials. In this work, the laminated titanium matrix composites consisting of ductile Ti-6Al-4V layer and (TiC+TiB)/Ti composite layer were successfully designed and fabricated by vacuum hot pressing plus hot rolling. A systematic investigation of the microstructural evolution, mechanical properties, strengthening and fracture mechanisms of the laminated composites has been conducted. The results indicate that the composite possesses a laminated structure, with the interfaces being free from delamination, porosity, and other defects, achieving a firm interfacial bonding. And the tensile testing results indicate that the composite shows superior strength-toughness synergistic properties due to the configuration design of laminated structure, with tensile strength and fracture strain reaching 1103.69 MPa and 13.04 %, respectively, which represent an enhancement of 11.67 % and 86.02 % over the (TiC+TiB)/Ti composite. The increase of strength was mainly attributed to grain refinement strengthening, second-phase strengthening and heterogeneous structure strengthening. Fractographic analysis reveals that crack deflection and the elongation of the crack propagation path are the primary causes for the increase in fracture strain. This work provides a new approach to the forming and manufacturing of high-quality laminated titanium matrix composites with synergy of strength and ductility. • The laminated titanium matrix composites with strong interface bonding were prepared by hot pressing-hot rolling method. • The synergistic enhancement of strength and ductility of the laminated composites was accomplished through the grain refinement, second-phase strengthening and heterogeneous structure strengthening. • The design of the laminated structure is capable of altering the crack propagation direction and lengthening its path, thereby improving the laminated composites' ductility. [ABSTRACT FROM AUTHOR]

In this study, commercially 1060 aluminum powders with median particle sizes of 20 μm, 25 μm, 50 μm and 100 μm are utilized as the matrix material to fabricate anodic samples of aluminum-air batteries through hot pressing sintering technique. This research explores the effect of grain size on battery discharge performance. The experimental outcomes indicate that the anode's discharge capacity diminishes progressively as grain size increases. At 25°C, the peak power density of the battery model declines from 257 mW/cm2 at 20 μm to 195 mW/cm2 at 100 μm. The constant current discharge tests exhibit that the discharge energy density and energy efficiency of the anodes increase as the current density increases from 60 mA/cm2 to 150 mA/cm2. The highest energy efficiency of 33.15% appears at 150 mA/cm2 for the anode of 20 μm particle size while the lowest energy efficiency of 17.32% occurs at 60 mA/cm2 for the anode of 100 μm particle size. Interestingly, the rates of hydrogen evolution and self-corrosion first decreased and then increased, with a notable transition at 50 μm. Microscopic observations revealed that the number of grain boundaries per unit area escalated with decreasing grain size, offering enhanced pathways for electrochemical and discharge reactions. The corrosion morphology varied from uniform pitting at smaller grain sizes to heterogeneous delamination at larger sizes. • Commercial aluminum powders are prepared for anode of AAB by hot pressing sintering. • Grain boundaries are the sites of electrochemical and discharge reactions. • Discharge performance decreases with increasing grain size. • Corrosion changes from uniform pitting to uneven peeling with increasing grain size. [ABSTRACT FROM AUTHOR]

Copper and its alloys are widely used in the preparation of metal matrix composites due to their thermal and electrical conductivity. This study aims to improve the mechanical, tribological and electrical conductivity properties of copper (Cu) matrix powders by adding certain amounts (10 wt%) of reduced graphene oxide (rGO) nanopowder, boron (B), nitrogen (N) and silicon (Si) reinforced rGO nanopowder. Hybrid composites were produced by powder metallurgy production methods. The samples were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX) and Fourier‐transform infrared spectroscopy (FT‐IR) analysis for reinforcement, homogeneity and phase identification. The mechanical and tribological properties of the hybrid composites were investigated by hardness, wear tests and temperature dependent electrical conductivity tests to determine the effect of the reinforcement materials on the Cu matrix structure. The maximum hardness value was obtained from the (Cu–rGO–Si–B–N) hybrid composite with an increase of 193% compared to the pure Cu sample. When the coefficient of friction values of RGO and reinforced rGO hybrid composites were examined, a 219.12% lower coefficient of friction value was observed in the (Cu–rGO–Si–B–N) sample compared to the pure Cu sample. The highest value was observed in the temperature dependent electrical resistance analysis in the rGO reinforced sample. [ABSTRACT FROM AUTHOR]

In this paper, the effects of hot pressing and cold pressing on the superconducting properties of pyrene (C16H10) added bulk MgB2 were compared. For this aim, the polycrystalline disk-shaped MgB2 samples with addition of 4 wt % C16H10 powder were fabricated by a pellet/closed tube method at 850 °C, after hot pressing at 200 °C and cold pressing. The XRD and SEM results showed that although a-lattice parameters reduce for both C16H10 added samples, the average crystallite size increases after cold pressing because of the accumulation and inhomogeneous distribution of C in the MgB2 structure while it reduces for the C16H10 added hot pressed sample. The resistivity measurements showed that the increment of electron scattering is higher for the C16H10 added cold pressed sample than that of the C16H10 added hot pressed one which shows relatively better grain connectivity, and the Tc values of the samples are not appreciably affected by the pressing conditions. From the magnetisation measurements the in-field Jc values at 10 K and 5.5 T were obtained as 8.41 × 103 A/cm2, 1.62 × 104 A/cm2, 6.90 × 103 A/cm2 and the Hirr values while Jc = 100 A/cm2 at 20 K were obtained as 5.99 T, 6.55 T and 6.19 T for the pure sample and the C16H10 added hot and cold pressed samples, respectively. The higher Jc and Hirr values obtained for the C16H10 added hot pressed sample is because of the homogenous C substitution into MgB2 grains, as compatible with its lower Δρ value, and thus increased flux pinning ability. [ABSTRACT FROM AUTHOR]

In this current study, the impact of manganese addition to 93 W-4.9Ni-2.1Cu-xMn (where x = 1, 2, 3, and 4 Wt%) on the microstructure, texture development, and grain boundary character distribution of tungsten heavy alloy (WHAs) was examined. The samples were produced through a vacuum hot press sintering, with parameters 50 MPa pressure, 10 °C/min heating rate, and 1450 °C sintering temperature for 20 min holding duration. To study the influence of manganese on the texture development and microstructure in conventional WHAs, electron backscatter diffraction (EBSD) was employed. The important findings from the EBSD analysis reveal that fibre texture (001) 〈111〉 and a higher fraction of low-angle grain boundaries in the Mn unalloyed compact resulted from extensive atomic jumps between the particles at elevated temperatures. Further texture analysis on the Mn-added compacts reveals that manganese oxide (MnO) formation during liquid phase sintering led to lower densification and randomized weak fibre texture development in manganese-alloyed compacts. In addition, the texture degradation in Mn-added compacts is mainly caused by recrystallization followed by sub-structural recovery during liquid phase sintering. This study indicates that increasing manganese content in WHAs stoichiometry led to a heterogeneous distribution of binder matrix (Ni Cu) in the sintered compact. As a result, W-4.9Ni-2.1Cu-4Mn alloy revealed decreased relative density (90.70%), microhardness (389.5 HV 0.5), and electrical conductivity (15.74% of IACS). [Display omitted] • The formation of manganese oxide in Mn-added WHAs leads to a reduction in density and properties. • The addition of Mn into WHAs induces alterations in the texture orientation of Ʃ3 CSL and HAGBs. • The {111} 〈001〉 texture became weaker as the manganese stoichiometry in WHAs increased. • Hardness and conductivity showed the W-Ni-Cu alloy does not benefit from Mn. [ABSTRACT FROM AUTHOR]

In the present study, dissimilar metal joints of SS321 and Ti–5Al-2.5Sn (α-Ti alloy) are produced by diffusion bonding at temperatures of 850, 900, and 950 °C under 10 MPa pressure for 30 min duration using a vacuum hot press (VHP). The interface of the joints was characterized through scanning electron microscopy coupled with energy dispersive spectroscopy and electron backscattered diffraction analysis for examining microstructure, morphology, and microchemistry across the interface. The effect of change in the heating process during diffusion bonding on the growth kinetics of interface layers was investigated. The interface of the joints comprised of intermetallic phases of σ phase, χ phase, (Fe,Cr) 2 Ti, FeTi and β-Ti. The joint produced at 900 °C has exhibited a maximum tensile strength of 315 MPa, 253 MPa, and 208 MPa at the test temperatures of −196 °C (77 K), room temperature (300 K), and 500 °C (773 K), respectively. Reduction in joint strength was noticed at test temperatures of RT and −196 °C for the samples bonded at a higher temperature of 950 °C due to the increased widths of the intermetallic phases at the interface. The effect of the bonding temperature on the tensile strength of the joints at an elevated test temperature of 500 °C was found to be negligible; however, the joints displayed good retention of strength along with substantial strain hardening followed by ductility at 500 °C. Fracture surfaces of RT and −196 °C tested samples showed the mixed mode of featureless smooth and cleavage fracture, whereas the 500 °C tested sample displayed planar interface failure. The zone of failure of the joints was noted to be around the interphase layer made of (Fe,Cr) 2 Ti + FeTi intermetallics. • SS321/Ti–5Al-2.5Sn joints produced by diffusion bonding using a vacuum hot press. • Tensile properties evaluated in the test temperature range of −196 °C–500 °C. • The joints displayed retention of strength along with strain hardening at 500 °C. • The interphase layer(s) (Fe,Cr) 2 Ti and FeTi influenced the failure of the joints. [ABSTRACT FROM AUTHOR]

Dense lead-free ceramics K 0.5 Na 0.5 NbO 3 were prepared via hot-press sintering in a relatively wide temperature window. Mean grain sizes of the ceramics increase from 160 nm to 720 nm due to changing the sintering parameters. All ceramics exhibit single orthorhombic phase, different domain sizes and domain morphology. Microstructure, dielectric, ferroelectric, and piezoelectric properties of the ceramics were studied systematically. For the ceramics with the mean grain size of 160 nm, the highest maximum polarization (P m) of 30.8 μC/cm2, dielectric constant (ϵ r) of 7119, piezoelectric constant (d 33) of 151 pC/N, and converse piezoelectric constant (d 33 *) of 291 p.m./V under the very low measurement electric field of 30 kV/cm were obtained. The excellent electrical properties are related to nano-scale fine domain configuration in fine-grained ceramics. [ABSTRACT FROM AUTHOR]

Hot press forming of Zn coated 22MnB5 is an effective way of producing ultrahigh strength structural parts for automobiles. The austenization process in hot press forming was investigated in our work. The results showed that the interfacial Fe 2 Al 5 inhibition layer in coated steel plays a critical role in diffusion during the austenization process. We proposed three stages of diffusion based on the level of stability of the inhibition layer (i.e. , the non-diffusion, inhomogeneous diffusion and homogeneous diffusion stages). The progression of diffusion in the coating through the three diffusion stages was discussed using Fe–Zn binary phase diagram and the Zn liquid +α-Fe(Zn) region was considered as the susceptible area to cracking. The penetration of liquid Zn into the substrate through grain boundary (GB) diffusion was observed after the breakdown of the interfacial Fe 2 Al 5 inhibition layer. In addition, we identified a transition diffusion layer at the interface which we assumed to be a result of the relatively long-term bulk diffusion of liquid Zn. The transition diffusion layer was analyzed following hot tensile tests. The structure of the layer was identified as body-centered cubic (BCC) α-Fe with large amounts of dissolved Zn. Although GB diffusion of liquid Zn into substrate was not observed because of the presence of the transition diffusion layer at the interface, the liquid metal induced embrittlement (LMIE) was not avoided for the Zn coated 22MnB5 in the hot tensile test. The results suggest that the BCC α-Fe phase is also sensitive to liquid Zn. • Interdiffusion between coating and substrate is controlled by the Fe 2 Al 5 inhibition layer. • Three diffusion modes (non-diffusion, inhomogeneous diffusion and homogeneous diffusion) are proposed. • The initial penetration of liquid Zinc through GB is observable. • Crack behavior is investigated using hot tensile test to determine mechanism of liquid Zinc induced embrittlement. [ABSTRACT FROM AUTHOR]

Abstract We investigated he thermoelectric (TE) properties and microstructures of Na-doped PbTe compounds, synthesized by various milling and sintering processes. It has been generally accepted that spark plasma sintering (SPS) inhibits grain growth due to the short sintering time, which is beneficial to the nano bulk composite. In contrast, we observed abnormal grain growth for SPS, unlike hot press (HP) sintering. Considering the Gibbs free energy change during sintering, the HP sintering increases internal energy while the SPS increases entropy energy, which causes the abnormal grain growth. Lattice strain and Fourier transform analyses of the transmission electron microscope images showed that the SPS sintered samples had more significant lattice strains and defects than the HP sintered samples. The low thermal conductivity of the SPS sintered samples was not from grain boundary phonon scattering but from phonon scattering by lattice strains and defects. The lattice strains and defects decreased electrical conductivity as well, resulting in deterioration of the power factor and thermoelectric performance. This suggests that the lattice strains and defects are more critical factors for enhancing thermoelectric performance than particle and grain size control. Highlights • Abnormal grain growth driven by entropy energy change is significant in spark plasma sintering. • SPS sintered samples have more significant lattice strains and defects than those of hot press. • Phonon scattering by lattice strains and defects decreases lattice thermal conductivity in SPS. • The lattice strains and defects decreases electrical conductivity as well. [ABSTRACT FROM AUTHOR]

Boron nitride-barium aluminosilicate (BN-BAS) composite ceramics were fabricated by the sol-gel method and hot-pressed sintering. The effects of the introduction method of BAS and sintering temperature on the phase assemblage, density, apparent porosity, mechanical properties and microstructures of the h-BN composite ceramics were investigated. The following two introduction methods were adopted: (A) BAS gel powder was prepared by the sol-gel method and then mixed with h-BN for hot pressing sintering, and (B) the BN-BAS composite powder was first prepared by the sol-gel method and then hot-pressed and sintered. The results indicate that the density, bending strength and fracture toughness of the latter are higher than those of the former when other conditions are the same. In the gel step of Group B, BAS has been coated on the surface of BN particles in dots, chemical bonding has existed, the distribution of BAS is more uniform, and it can better serve as a sintering aid. The BN-BAS composites prepared by both methods achieved the maximum mechanical properties at a sintering temperature of 1700 °C, and the density, apparent porosity, bending strength and fracture toughness of Group A were 2.40 g/cm3, 1.82%, 132.8 MPa and 2.3 MPa m1/2, while those of Group B were 2.42 g/cm3, 1.45%, 162.9 MPa and 2.7 MP m1/2. [ABSTRACT FROM AUTHOR]

In this study, the effects of rhenium on the evolution of microstructure and texture in hot press sintered tungsten heavy alloy (93W-4.9Ni-2.1Cu) is examined. Rhenium is added (i.e., increased rhenium from 0 to 1 wt % with interval of 0.25 wt %) to a conventional tungsten heavy alloy while maintaining a constant Ni: Cu (7:3) ratio. The samples were prepared using a vacuum hot press sintering method with parameters including 50 MPa pressure, 10 °C/min heating rate, and 1450 °C temperature for a 20-min holding time. The impact of rhenium on densification, crystallographic texture development, and grain boundary features of Re alloyed WHA was studied using electron backscattered diffraction (EBSD). The development of grain boundary texture was the result of a Ʃ3 CSL increase in sintered compact. The base alloy exhibits fibre texture in the (001) plane with the <111> direction and a higher proportion of low-angle grain boundaries. Reduced kinetics of grain growth during sintering led to a higher degree of densification and randomised weak fibre texture in rhenium-alloyed samples. The deterioration of texture in the (001) <111> direction in rhenium-added alloys was caused by recrystallization following recovery during sintering. Metallographic studies reveal that an increase in rhenium in the WHA's stoichiometry resulted in particle refinement during sintering, thereby enhancing the WHA's properties. Maximum micro-hardness (432 HV 0.5), electrical conductivity (23.74 % of IACS), and relative density (99.90 %) were observed in a 93W-4.9Ni-2.1Cu (Re 1 wt% alloy). • A close theoretical density of the 92W-4.9Ni-2.1Cu-1Re alloy was obtained. • An increase in the Ʃ3 CSL boundary impacts the grain boundary's texture. • Increasing rhenium stoichiometry in WHA resulted in a (111) 001> texture that is weaker. • Hardness and conductivity showed Re is an effective reinforcement for WHA. [ABSTRACT FROM AUTHOR]

Different stoichiometries of lead-free BaZr 0.2 Ti 0.8 O 3 –Ba 0.7 Ca 0.3 TiO 3 (BCZT) prepared by mechanosynthesis and sintered by either conventional sintering (CS) or hot pressing (HP) techniques were studied to establish the dependence of piezoelectric and dielectric properties on sintering parameters and microstructure. All synthesized stoichiometries showed a pseudocubic perovskite phase with homogeneously distributed A- and B-cations in the structure. The BCZT retained the pseudocubic symmetry after sintering and an average grain size <1.8 µm was obtained in all cases. HP sintering hindered the secondary phase segregation observed in the CS ceramics and increased the relative density. Piezoelectric coefficients (d 33) ranging from 5.1 to 21 pC/N and from 10.0 to 88.0 pC/N were obtained for CS and HP ceramics, respectively, despite the pseudocubic symmetry and the fine grain size. The higher d 33 values for the HP ceramics are a consequence of the higher density, better chemical homogeneity and lower sintering temperature and time required for the mechanosynthesized BCZT powders with high sintering activity. • BCZT were successfully formed by high-energy mechanosynthesis after 120 min. • Fine-grained BCZT were obtained by either conventional sintering or hot pressing. • HP sintering favored the presence of different crystal structures and higher density. • d 33 values ranged from 5.1 to 88.0 pC/N, depending on stoichiometry and sintering. [ABSTRACT FROM AUTHOR]

Graphite/copper composites have great potential for tribological applications because of their high thermal and abrasion resistance. In this study, we successfully manufactured graphite/copper composites that demonstrated superior thermal conductivity and wear resistance by employing microwave hot press sintering (MHPS). The results demonstrated an enhancement in the density and hardness of the composites as the graphite particle size increased, owing to the influence of MHPS. Meanwhile, the graphite/copper composite with a graphite particle size of 300 µm has excellent thermal conductivity and friction properties, with a thermal conductivity of up to 679.5 W/mK and a wear rate of only 3.019 10−6 cm3/(N · m). The work is expected to provide a new route for the developing highly thermally conductive and abrasion-resistant materials. [ABSTRACT FROM AUTHOR]

The bending angle at the peak load is regarded as the most important parameter for evaluating bending properties of hot-press-forming (HPF) steels. However, it is not a mechanics-based parameter for the bending criterion, and the data interpretation is difficult because bending criteria in relation with microstructures and associated bending mechanisms have not been verified yet. In this study, effects of coating and baking treatments on bending angles at the peak load of three kinds of 1470 MPa-grade HPF steels were investigated by interrupted three-point bending tests coupled with direct microstructural observation. According to direct observations of sequential cracking processes of V-shaped crack (V-crack), bending procedures were classified into four stages: (1) formation of small V-crack, (2) increase in number and size of V-cracks, (3) initiation of shear-crack propagation from the V-crack tip, and (4) further propagation and opening of the shear crack. The minimum bending angle required for initiating the shear-crack propagation from the V-crack tip was defined as a critical angle, which meant the boundary between the 2nd and 3rd stages. The present bending behavior related with critical bending angle and V-cracking could be interpreted similarly by the fracture-mechanics concept, i.e., the initiation of shear-crack propagation. [ABSTRACT FROM AUTHOR]

Transparent Lanthanum-modified lead zirconate titanate ceramics (PLZT 7.4/70/30) with low content of excess lead oxide (PbO) were successfully prepared by a novel vacuum/oxygen hot press sintering process. The phase structure, microstructure, electrical properties and electro-optic scattering performance of PLZT ceramics as a function of excess PbO in the starting powders have been studied and analyzed. As a result, these ceramics exhibited an ultra-high optical transmittance (>69.4% at 1064 nm; thickness 1 mm) from visible to near-infrared wavelength. Herein, we significantly reduce the use of PbO as an auxiliary agent for sintering. This puts forward a good route to meet the objectives of environmental protection and sustainable development. [ABSTRACT FROM AUTHOR]

A novel method based on hot press sintering was proposed to fabricate the Al/Ti laminated composite, and the effects of sintering parameters on microstructure, interfacial structure, and mechanical properties were thoughtful examined. The results showed that insufficient sintering caused obvious voids and cracks at Al/Ti interface. With the increase of temperature or holding time, a good metallurgical bonding without defects was achieved, and both the recrystallization fraction and grain size of α phase in Ti layer increased, accompanied by the transformation of α to β phase and growth of intermetallic phase. The microstructure variation of Al layer is not evident with changing the sintering parameters. Due to the relatively low formation energy, the nanoscale TiAl 3 phase with massive stacking faults formed at Al/Ti interface, and lots of dislocations existed at Al layer near the interface. The voids and cracks formed at Al/Ti interface led to the premature failure of laminate. On the basis of the metallurgical bonding and small TiAl 3 phase, the high fraction and texture intensity of α phase were the dominated strengthening factors. Moreover, the back stress generated at Al/Ti interface contributes to an extra strengthening. The superior mechanical properties of Al/Ti laminate with a tensile strength of 670.9 MPa and a fracture strain of 0.33 were obtained with the sintering temperature of 600 °C and holding time of 2 h. [Display omitted] • A superior combination of strength and fracture strain of Al/Ti laminate was obtained by hot press sintering. • Grain size, recrystallization fraction, and texture intensity of α phase were sensitive to sintering parameters. • Nanoscale TiAl 3 phase with massive stacking faults formed toward Al layer at Al/Ti interface. • Achieving metallurgical bonding and minimizing the size of TiAl 3 facilitate a strong strengthening effect. [ABSTRACT FROM AUTHOR]