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In order to clarify the asymmetric basal texture effects on the stretchability and the microstructure variations of magnesium alloy sheet, two kinds of stretch forming samples were extracted along the rolling direction (RD) and the transverse direction (TD) from ZK60 magnesium alloy sheet with asymmetric basal texture. Their variations involving the microstructure and the stretch formability were investigated using a visco-plastic self-consistent model, along with the three-dimensional finite element method. The experimental and simulated results together showed that the plastic deformation during stretch forming was concentrated in the central region of the stretch sample. Such plastic deformation was more easily propagated into the surrounding area in the TD sample, making its stretch formability higher by nearly 50.7 % than the RD sample. This was attributed to the weak basal texture in the TD sample which activated more basal slip and tension twinning and consequently increased its hardenability. Additionally, with the variation of the stretch forming behavior, the activation of basal slip narrowed the spread angle of the basal pole for the TD sample, while only increased the basal texture intensity for the RD sample. Moreover, activation of the prismatic slip rotated the <10−10> crystal direction toward the major strain direction (LD), promoting the development of <10−10>//LD-type texture in both samples. These results indicated that the comprehensive stretchability improvement of magnesium alloy sheet required weakening the basal texture symmetrically instead of asymmetrically. • The stretch plastic deformation was concentrated in the central region of stretch sample. • The stretchability of the sample with weak basal texture direction was higher by 50.7 %. • Different stretch behaviors arose from the different contributions of each deformation mode. • Weakening the basal texture symmetrically could improve the stretchability comprehensively. [ABSTRACT FROM AUTHOR]

• C70250 plate with columnar grains along casting direction were produced by HCCM continuous casting. • Solid-liquid interface location is a key factor to control precipitate content in columnar grains. • Columnar grain plate had better plasticity than equiaxed grain plate due to grain orientation. C70250 (Cu-2.6 wt%Ni-0.5 wt%Si) alloy plates with straight columnar grains, inclined columnar grains and equiaxed grains were produced by a heating-cooling combined mold (HCCM) horizontal continuous casting, respectively, and the influences of microstructure on the mechanical properties of the alloy were studied. The results showed that, when the casting speed was 30 mm/min, the straight columnar grains along the casting direction formed in the C70250 alloy plate and the precipitate content was relatively high, ～ 10%. When the casting speed was 50 mm/min and 80 mm/min, inclined columnar grains and equiaxed grains formed, respectively, with a low precipitate content of 6%. The high casting speed made the solid-liquid interface at the entrance of the cold mold and the solidified plate was cooled rapidly due to strong cooling effect, which suppressed formation of precipitated phase. The yield strength of the alloy plate with equiaxed grains were 219 MPa and the elongation to failure was 36%. For the plate with inclined columnar grains, its yield strength (76 MPa) were obviously lower than that of the other two plates and the elongation reached 45%. Compared with the equiaxed grain plate, the columnar grain plate had smaller grain orientation difference, better intergranular deformation compatibility and intergranular deformation uniformity, which was mainly responsible for its better plasticity. [ABSTRACT FROM AUTHOR]

CoCrFeMnNi HEA coatings incorporating WC ceramic particles with varying contents (0%, 10%, 20%, 30%, and 40%) are synthesized by laser cladding in this study. The phase evolution, strengthening mechanisms, and dry sliding wear behavior are investigated. The microstructure analysis revealed that coatings with WC content up to 20% consist of a single FCC phase, while those with WC content exceeding 30% exhibit a combination of FCC and polymorphic M 3 W 3 C phases. The microhardness increases from 169HV to 517HV with the content of WC varies from 0% to 40%. The contributions of precipitation strengthening and dislocation strengthening are the primary factors driving hardness increment. The presence of M3W3C further contributes to precipitation strengthening, resulting in enhanced hardness with increasing WC content. Moreover, the coating with 30% WC particles exhibits the most superior wear resistance, with a significantly reduced volume wear rate of 2.37 × 10−6 mm3/(N·m), which is merely 0.7% in comparison to the WC-free coating. With increased WC content, the wear mechanism of the coatings shifts from adhesive wear to oxidation wear, attributed to the hierarchical interfaces between the FCC matrix and the WC/M 3 W 3 C phase. This study offers valuable insights for enhancing the durability and performance of advanced coatings. [Display omitted] • CoCrFeMnNi high entropy alloy coatings incorporating WC ceramic particles were synthesized successfully by laser cladding. • The formation mechanism of carbides with different morphologies was revealed. • The effect of W-atom and C-atom content in the melt pool on the phase composition was investigated. • The contribution of each strengthening mechanism to the microhardness was quantitatively analyzed. [ABSTRACT FROM AUTHOR]

• This paper clarifies the effect of billet microstructure and deformation on austenite grain growth in forging heating. • This paper provides important guidance for rolling process of medium-carbon microalloyed steel billets for hot forging. • This paper provides a new insight into the control and prediction of austenite grain growth. [Display omitted] We prepared samples with different ferrite-pearlite characteristics and deformation by heat treatment and Gleeble thermocompression respectively. Then, the different samples are rapidly heated to 1200 °C for 60 s to study the austenite grain growth. The study results show that the ferrite-pearlite characteristics has little effect on austenite grain growth. With the mean austenite grain size (MAGS) of billet microstructure increasing from 14 µm to 56 µm, the MAGS after heating only increases from 47 µm to 56 µm. With the cooling rate of billet samples increasing from 0.1 °C/s to 1.0 °C/s, the MAGS after heating has basically no change. However, the deformation of billet samples has significant effect on the austenite grain growth. With the deformation at 1150 °C increasing from 10% to 50%, the MAGS after heating decreases from 63 µm to 31 µm. In the meanwhile, the mean distance between element segregation bands decreases from 115 µm to 33 µm, and the mean width of element segregation bands decreases from 70 µm to 20 µm. Electron probe microanalysis shows that the segregation region has higher Si, Cr, Mn and V contents, which generate stronger solute drag effect on austenite grain boundaries. Deformation can crush the as-cast grains and make the segregation bands fine and dispersed, further refining the austenite grains after heating. [ABSTRACT FROM AUTHOR]

Abstract Heating-cooling combined mold (HCCM) horizontal continuous casting was used to produce Ф70 mm × 3.5 mm CuNi10Fe1.8Mn1 alloy tubes. The as-cast tube had good surface quality, strong axial columnar grains and high elongation to failure of 45%, and can be directly drawn without surface treatment. The maximum cumulative cold deformation amount reached 94%. For the small deformation amount (<46%), dislocation sliding was main deformation mechanism, numerous dislocation cells formed and microregion crystal rotation in grains happened. When the deformation amount was 76%, shear deformation extent increased and many parallel shear bands formed in gains. With increasing the deformation amount to 92%, a large number of shear bands in different directions formed and the intersecting of shear bands induced displacement of 100–200 nm themselves, which formed wave-shaped deformation structures. With increasing the deformation amount, the tensile strength and hardness of the tube increased from 235 MPa and 86 HV of the as-cast tube to 585 MPa and 168 HV of 94% deformation amount, but the elongation to failure reduced to 6.6%. The process of HCCM horizontal continuous casting→drawing can work as a new compact method to produce thin-walled cupronickel alloy tube. Graphical abstract Image 1 Highlights • CuNi10Fe1.8Mn1 casting tube was drawn by a reduction of 94% without intermediate annealing. • With an increase of deformation amount, deformation mechanism was dislocation sliding and shear successively. • HCCM horizontal continuous casting.→drawing works as a compact method to produce cupronickel alloy tube [ABSTRACT FROM AUTHOR]

The refinement of grains to the size of ∼ 600 nm is observed in a nano-scaled Al 2 O 3 dispersion-strengthened (ODS) Cu alloy under compression distortion. The plastic deformation mechanism of the ODS Cu alloy is studied by the observation and analysis of the evolution of grain size, dislocation density and distribution, and texture orientation during compression process. The deformation process can be divided into four stages, i.e., leaner deformation stage, plastic-strengthening transition stage, relative steady state stage and softening stage under ∼ 90 % compression, according to the stress-strain curves. The grains are found split into refined sub-grains by the net-like entangled dislocations due to the pinning effect of nano-scaled Al 2 O 3 particles. The dislocation density of ODS Cu is found increasing within 30 % compression, and then remaining to a plateau under ∼ 30 %−60 % compression, but then under ∼ 60 %−80 % and ∼ 80 %−90 % compression, the dislocation density increases firstly and then decreases. The crystal orientation is transformed from the Goss texture {110}< 001 > to the inhomogeneous Shear texture {001}< 110 > during the compression process, due to the rotation of grains. This study provides a further understanding of the strengthening mechanism and a guidance for the design of ODS Cu alloys, which is significant for the prospective future structural applications. • The stress-strain curve of oxide dispersion strengthened copper (ODS) alloy was divided into four stages including leaner deformation stage, plastic-strengthening transition stage, relative steady state stage and softening stage. • The well fitted piecewise function model was used to describe the four stages. • The matrix grains are splitted into refined sub-grains with size of ∼ 600 nm by the net-like entangled dislocations due to the pinning effect of nanometer scaled Al 2 O 3 particles. • Through the analysis of microstructure evolution, the grain refinement, texture evolution, the four stages plastic deformation and softening mechanism of ODS copper alloy were clarified. [ABSTRACT FROM AUTHOR]

Electrochemical nitrogen reduction reaction has recently received increasing attention due to its ability to synthesize ammonia under ambient conditions. However, the low ammonia yields and Faradaic efficiency hinder its further development, which necessitates the use of high-performance catalysts. Hence, in this study, a self-supporting carbon mat with FeNi-doped Co catalysts (Fe 1 Ni 0.2 Co 145) fabricated by electrospinning was used as an electrode (FeNi-Co@CM) for electrochemical ammonia synthesis. The electrochemical performance of the FeNi-Co@CM electrode is evaluated in a three-electrode setup with FeNi-Co@CM as working electrode, a platinum mesh as counter electrode, and a Ag/AgCl electrode as reference electrode. The experimental investigations produce an ammonia yield rate of 27.9 μg h−1 mg−1 and a Faradaic efficiency of 1.52 % in 1.0 M KOH, which is higher than most of the reported data where iron-group-based electrocatalysts were employed. The verification results from multiple sets of control experiments indicated that the ammonia detected is generated by the nitrogen reduction reaction rather than the contaminants in the surrounding environment. In addition, the results of the stability test show that the FeNi-Co@CM electrode can maintain a high level of ammonia production for more than ten cycles. The working mechanism of nitrogen reduction reaction based on FeNi-Co@CM electrode is also discussed at various scales, including the electrode scale, the catalyst scale, and the atomic scale. This study therefore provides an in-depth understanding of the nitrogen reduction reaction from various perspectives, such as mass transport, reaction interfaces, and reaction intermediates. [Display omitted] • Achieving an ammonia yield rate of 27.9 μg h−1 mg−1 and a Faradaic efficiency of 1.52 %. • Demonstrating good stability for 10 cycles by the FeNi-Co@CM electrode. • Revealing the reaction mechanism of NRR from various scales. [ABSTRACT FROM AUTHOR]

Lithium metal has garnered increasing attention, and is considered to be the most promising anode material for the next-generation rechargeable batteries with higher energy density such as lithium-sulfur, lithium-air and solid-state batteries. However, several serious challenges limit the commercial application of lithium metal batteries, including uncontrolled lithium dendrite growth, inherent volume expansion, and low Coulombic efficiency. Here, a nitrogen-doped porous nanofiber scaffold decorated with FeNi alloy nanoparticles with high lithophilicity is proposed by the electrospinning technique. The porous structure and the doping of FeNi alloy can expose more lithium nucleation active sites, and effectively reduce the nucleation overpotential of lithium metal to guide the uniform deposition of lithium. The porous structure formed by the sublimation of polymethyl methacrylate can effectively relieve the volume expansion and structural stress during the cycling process. As a result, excellent cycle stability and outstanding rate performance are observed in the tests of symmetric cells, highlighting the feasibility of the designed bimetallic doped carbon fiber scaffold for developing high-performance lithium metal anodes. The present work provides new strategies to solve the formation of lithium dendrites and brings new inspiration for the design and construction of high-efficiency lithium anodes and other secondary batteries anodes. [Display omitted] • Porous carbon scaffold decorated with FeNi alloy is designed by electrospinning. • The porous structure and the doping of FeNi alloy can expose more active sites. • The 3D porous host can relieve the volume expansion during the cycling process. • Excellent cycle stability and outstanding rate performance can be observed. [ABSTRACT FROM AUTHOR]

A Cu-3.0 wt% Ti alloy is fabricated by a novel non-vacuum short-process based on heating-cooling combined mold (HCCM) continuous casting in this study. Similar properties including tensile strength, hardness and electrical conductivity are obtained by this newly developed process, compared to its counterpart alloy prepared by conventional vacuum smelting. The tensile strength, total elongation and conductivity of the HCCM prepared Cu-3 wt% Ti alloy were 895 MPa, 13% and 13.00% IACS, respectively, after 95% deformation and aging treatment at 450 °C for 1 h. The cast materials fabricated by HCCM method can be directly cold rolled and aged after solution treatment without hot deformation such as hot forging. Through the HCCM continuous casting method, not only the Cu-Ti alloy can be fabricated under non-vacuum conditions, but also the fabrication process can apparently shortened by shortening the solid solution treatment time. Similar precipitation process is also found in the Cu-3.0 wt% Ti alloy prepared by this method. The precipitation of the ordered, metastable and coherent β'- Cu 4 Ti phase with body-centered tetragonal (bct) structure are formed in the early stage of aging treatment, which is transformed into stable β- Cu 3 Ti with an orthogonal structure in the over-aging stage. The precipitation hardening of β'- Cu 4 Ti phase, i.e., Orowan strengthening effect, is believed to be the leading strengthening mechanism in this alloy. [Display omitted] • Cu-3 wt% Ti alloy with high properties was prepared without vacuum for the first time. • New process without hot deformation was developed to improve yield and economy. • Solid solution time was significantly shortened by HCCM continuous casting. [ABSTRACT FROM AUTHOR]

• Effect of homogenization on HCCM continuous casting tube billets is clarified. • HCCM continuous casting improves homogenization effectiveness significantly. • Peculiar interlaced Mg 2 Si and Al 6 (Fe,Mn) phases are obtained by HCCM continuous casting. AA 5052 aluminum alloy tube billets were prepared by HCCM vertical continuous casting to study the effect of homogenization temperature and time on the second phases and mechanical properties. The volume fraction of constituent, length of constituent colonies, number density and volume fraction of dispersoids were examined in different homogenization conditions. Optimized homogenization can be obtained at 560 °C for 20 h, and the elongation of the HCCM continuous casting billet increases from 25.5% (as-cast) to 35.5%, while that of the semicontinuous casting billets only increases from 21.5% (as-cast) to 23.5%. In particular, fine and interlaced Mg 2 Si and Al 6 (Fe,Mn) phases are obtained after HCCM continuous casting, which is different from the separated distribution phases after traditional semicontinuous casting and improves the effectiveness of homogenization treatment. [ABSTRACT FROM AUTHOR]