Pub Date : 2026-08-01Epub Date: 2026-01-22DOI: 10.1016/j.ijrmhm.2026.107691
Ruochong Wang , Yunan Fan , Zihan Yang , Weiwei He , Li Wang , Bin Liu , Yang Lu , Yong Liu
The influences of printing process on metallurgical quality and wear resistance of NiCu-diamond composites were quantitatively analyzed. The NiCu-diamond composite with low porosity (∼1.6 vol%) and low loss of diamond particles (only 0.5 vol%) was successfully fabricated, at an electron beam current of 2.4 mA, and a scanning rate of 1 m·s−1. The wear rate of the NiCu-diamond composite was as low as 5.0 × 10−7 mm3·N−1·m−1, and coefficients of friction (COFs) within 0.02–0.05. These values represent a substantial reduction compared to the corresponding values of 43.7 × 10−7 mm3·N−1·m−1 and 0.18–0.28. The dense tribofilm formed during wet friction (in 3.5 wt% NaCl solution) hinders further wear of the substrate, leading to lower COFs and wear rates than those of dry friction. The PBF-ed NiCu-diamond composites show excellent wet friction and wear properties with COFs lower than 0.04 and a wear rate of 1.6 × 10−7 mm3·N−1·m−1.
{"title":"Friction and wear behavior of NiCu-diamond composites fabricated by defect-controlled powder bed fusion (PBF) process","authors":"Ruochong Wang , Yunan Fan , Zihan Yang , Weiwei He , Li Wang , Bin Liu , Yang Lu , Yong Liu","doi":"10.1016/j.ijrmhm.2026.107691","DOIUrl":"10.1016/j.ijrmhm.2026.107691","url":null,"abstract":"<div><div>The influences of printing process on metallurgical quality and wear resistance of NiCu-diamond composites were quantitatively analyzed. The NiCu-diamond composite with low porosity (∼1.6 vol%) and low loss of diamond particles (only 0.5 vol%) was successfully fabricated, at an electron beam current of 2.4 mA, and a scanning rate of 1 m·s<sup>−1</sup>. The wear rate of the NiCu-diamond composite was as low as 5.0 × 10<sup>−7</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>, and coefficients of friction (COFs) within 0.02–0.05. These values represent a substantial reduction compared to the corresponding values of 43.7 × 10<sup>−7</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup> and 0.18–0.28. The dense tribofilm formed during wet friction (in 3.5 wt% NaCl solution) hinders further wear of the substrate, leading to lower COFs and wear rates than those of dry friction. The PBF-ed NiCu-diamond composites show excellent wet friction and wear properties with COFs lower than 0.04 and a wear rate of 1.6 × 10<sup>−7</sup> mm<sup>3</sup>·N<sup>−1</sup>·m<sup>−1</sup>.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"138 ","pages":"Article 107691"},"PeriodicalIF":4.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146032957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-10DOI: 10.1016/j.jeurceramsoc.2026.118227
Zerong Zhang , Yanan Wang , Zhan Gao , Xin Liu , Lei Wang , Qiuliang Wang
In this work, five different RE123 samples were prepared via solid-state sintering in flowing air, including (Eu0.2Gd0.2Y0.2Er0.2Yb0.2)BCO, (Eu0.25Gd0.25Y0.25Er0.25)BCO, (Eu0.33Gd0.33Y0.33)BCO, (Nd0.25Eu0.25Gd0.25Y0.25)BCO and (La0.2Nd0.2Y0.2Er0.2Yb0.2)BCO. Their phase constituents, phase stabilities, superconducting properties and microstructures were systematically investigated. Results indicated that RE123 samples with almost pure superconducting phase could be prepared; the superconducting transition temperature (Tc) of each sample was > 90.0 K. The lattice parameters and peritectic decomposition temperature (TP) increased with the average ionic radius of RE3 + at the RE site in RE123 samples. The critical current density (Jc) was considerably affected by the constituent elements at the RE site. Specifically, of all samples, (Eu0.25Gd0.25Y0.25Er0.25)BCO exhibited the highest self-field Jc of 373 kA/cm2 at 4.2 K; this remarkable superconducting performance could be mainly attributed to its higher superconducting volume fraction, but meanwhile, the configuration entropy at the RE site also have contributed to its high Jc value due to the formation of nanoscale SFs.
{"title":"Synthesis and characterization of REBa2Cu3O7-y superconductors with multiple rare earth elements","authors":"Zerong Zhang , Yanan Wang , Zhan Gao , Xin Liu , Lei Wang , Qiuliang Wang","doi":"10.1016/j.jeurceramsoc.2026.118227","DOIUrl":"10.1016/j.jeurceramsoc.2026.118227","url":null,"abstract":"<div><div>In this work, five different RE123 samples were prepared via solid-state sintering in flowing air, including (Eu<sub>0.2</sub>Gd<sub>0.2</sub>Y<sub>0.2</sub>Er<sub>0.2</sub>Yb<sub>0.2</sub>)BCO, (Eu<sub>0.25</sub>Gd<sub>0.25</sub>Y<sub>0.25</sub>Er<sub>0.25</sub>)BCO, (Eu<sub>0.33</sub>Gd<sub>0.33</sub>Y<sub>0.33</sub>)BCO, (Nd<sub>0.25</sub>Eu<sub>0.25</sub>Gd<sub>0.25</sub>Y<sub>0.25</sub>)BCO and (La<sub>0.2</sub>Nd<sub>0.2</sub>Y<sub>0.2</sub>Er<sub>0.2</sub>Yb<sub>0.2</sub>)BCO. Their phase constituents, phase stabilities, superconducting properties and microstructures were systematically investigated. Results indicated that RE123 samples with almost pure superconducting phase could be prepared; the superconducting transition temperature (T<sub>c</sub>) of each sample was > 90.0 K. The lattice parameters and peritectic decomposition temperature (T<sub>P</sub>) increased with the average ionic radius of RE<sup>3 +</sup> at the RE site in RE123 samples. The critical current density (J<sub>c</sub>) was considerably affected by the constituent elements at the RE site. Specifically, of all samples, (Eu<sub>0.25</sub>Gd<sub>0.25</sub>Y<sub>0.25</sub>Er<sub>0.25</sub>)BCO exhibited the highest self-field J<sub>c</sub> of 373 kA/<sub>c</sub>m<sup>2</sup> at 4.2 K; this remarkable superconducting performance could be mainly attributed to its higher superconducting volume fraction, but meanwhile, the configuration entropy at the RE site also have contributed to its high J<sub>c</sub> value due to the formation of nanoscale SFs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118227"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-04DOI: 10.1016/j.jeurceramsoc.2026.118211
Jiawen Song , Haoran Wei , Zhengyuan Shen , Qiang Yang , Ling Xu , Jiahong Niu
In response to the demands for the intelligent thermal structure of aircraft, on-line health monitoring based on high-temperature resistance measurement of ceramic matrix composites (CMCs) can effectively identify the damage state of CMCs. However, highly reliable interconnects between CMCs and metal electrodes remain a major challenge, requiring high temperature resistance, high interface strength and excellent electrical stability. High-performance interconnects were realized by the diffusion reaction of a novel hybrid solder (polysilazane and Ag-Cu-Ti) between Mo electrodes and Cf/SiC composites. Highly conductive and temperature resistant Ti(C,N) and (Ti,Mo)5Si3 were formed on the Cf/SiC and Mo electrode side respectively, and a mixed metal/ ceramic structure Ag(C)/Cu/Ti(C,N) were formed in the hybrid solder matrix. The high-performance interconnects exhibit high interface strength of 14.97–19.07 MPa. The resistance measurement can be conducted stably up to 1200 ℃ in an argon atmosphere and 825 ℃ in air with excellent resistance stability and repeatability.
{"title":"High-performance interconnects for high-temperature resistance measurement toward on-line health monitoring of Cf/SiC composites","authors":"Jiawen Song , Haoran Wei , Zhengyuan Shen , Qiang Yang , Ling Xu , Jiahong Niu","doi":"10.1016/j.jeurceramsoc.2026.118211","DOIUrl":"10.1016/j.jeurceramsoc.2026.118211","url":null,"abstract":"<div><div>In response to the demands for the intelligent thermal structure of aircraft, on-line health monitoring based on high-temperature resistance measurement of ceramic matrix composites (CMCs) can effectively identify the damage state of CMCs. However, highly reliable interconnects between CMCs and metal electrodes remain a major challenge, requiring high temperature resistance, high interface strength and excellent electrical stability. High-performance interconnects were realized by the diffusion reaction of a novel hybrid solder (polysilazane and Ag-Cu-Ti) between Mo electrodes and C<sub>f</sub>/SiC composites. Highly conductive and temperature resistant Ti(C,N) and (Ti,Mo)<sub>5</sub>Si<sub>3</sub> were formed on the C<sub>f</sub>/SiC and Mo electrode side respectively, and a mixed metal/ ceramic structure Ag(C)/Cu/Ti(C,N) were formed in the hybrid solder matrix. The high-performance interconnects exhibit high interface strength of 14.97–19.07 MPa. The resistance measurement can be conducted stably up to 1200 ℃ in an argon atmosphere and 825 ℃ in air with excellent resistance stability and repeatability.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118211"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-01-31DOI: 10.1016/j.jeurceramsoc.2026.118182
Min-Soo Nam , Sahn Nahm , Seongwon Kim
Environmental barrier coatings (EBCs) are essential for protecting SiCf/SiC ceramic matrix composites from water vapor recession and calcia-magnesia-aluminosilicate (CMAS) corrosion in gas turbines. In this study, (YbxSc1−x)2Si2O7 solid solutions with varying Yb/Sc ratios are evaluated as CMAS-resistant EBC topcoat candidates. Five compositions are synthesized and tested at 1500 °C. Corrosion resistance improves as the optical basicity of the disilicate matches that of CMAS, minimizing chemical reactions and apatite formation; Sc-containing compositions exhibit the best performance. Increasing Sc content decreases the ionic radius and lattice parameters, further inhibiting Ca2+ –to–RE3+ substitution. Microstructural analysis shows Yb-rich samples retain surface CMAS, whereas Sc-rich samples experience rapid grain-boundary infiltration with less reaction. Thermophysical measurements confirm low, stable thermal conductivity and coefficient of thermal expansion compatibility with SiCf/SiC substrates. These results indicate that (YbxSc1−x)2Si2O7 solid solutions offer a balanced combination of CMAS corrosion resistance, thermal compatibility, and low thermal conductivity for robust EBCs.
{"title":"Reaction-controlled effects of (YbxSc1-x)2Si2O7 solid solution against molten calcia-magnesia-aluminosilicate (CMAS) corrosion for environmental barrier coating application","authors":"Min-Soo Nam , Sahn Nahm , Seongwon Kim","doi":"10.1016/j.jeurceramsoc.2026.118182","DOIUrl":"10.1016/j.jeurceramsoc.2026.118182","url":null,"abstract":"<div><div>Environmental barrier coatings (EBCs) are essential for protecting SiC<sub>f</sub>/SiC ceramic matrix composites from water vapor recession and calcia-magnesia-aluminosilicate (CMAS) corrosion in gas turbines. In this study, (Yb<sub>x</sub>Sc<sub>1−x</sub>)<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> solid solutions with varying Yb/Sc ratios are evaluated as CMAS-resistant EBC topcoat candidates. Five compositions are synthesized and tested at 1500 °C. Corrosion resistance improves as the optical basicity of the disilicate matches that of CMAS, minimizing chemical reactions and apatite formation; Sc-containing compositions exhibit the best performance. Increasing Sc content decreases the ionic radius and lattice parameters, further inhibiting Ca<sup>2</sup><sup>+</sup> –to–RE<sup>3+</sup> substitution. Microstructural analysis shows Yb-rich samples retain surface CMAS, whereas Sc-rich samples experience rapid grain-boundary infiltration with less reaction. Thermophysical measurements confirm low, stable thermal conductivity and coefficient of thermal expansion compatibility with SiC<sub>f</sub>/SiC substrates. These results indicate that (Yb<sub>x</sub>Sc<sub>1−x</sub>)<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> solid solutions offer a balanced combination of CMAS corrosion resistance, thermal compatibility, and low thermal conductivity for robust EBCs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118182"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-01-26DOI: 10.1016/j.jeurceramsoc.2026.118174
Haoyuan Li , Mohsen Asle Zaeem
This work investigates the role of oxygen vacancies at grain boundaries in governing the ferroelastic behavior of tetragonal prime yttria-stabilized zirconia (t’-YSZ). Using molecular dynamics simulations, ferroelastic domains are induced via quenching and subsequently subjected to mechanical deformation to assess the effects of oxygen vacancy concentration and spatial distribution on domain switching. A Buckingham interatomic potential is employed to capture both t’-YSZ phase formation and ferroelastic domain switching. The results reveal that oxygen vacancy accumulation inhibits domain formation and suppresses ferroelastic reorientation via pinning effects, particularly near grain boundaries. These findings show that grain boundaries act as major sites of oxygen vacancy accumulation, with their structural geometry controlling how vacancies redistribute under compression and tension, thereby directly shaping the ferroelastic switching behavior of t’-YSZ.
{"title":"Effect of oxygen vacancies at grain boundaries on ferroelastic behavior of yttria stabilized zirconia","authors":"Haoyuan Li , Mohsen Asle Zaeem","doi":"10.1016/j.jeurceramsoc.2026.118174","DOIUrl":"10.1016/j.jeurceramsoc.2026.118174","url":null,"abstract":"<div><div>This work investigates the role of oxygen vacancies at grain boundaries in governing the ferroelastic behavior of tetragonal prime yttria-stabilized zirconia (t’-YSZ). Using molecular dynamics simulations, ferroelastic domains are induced via quenching and subsequently subjected to mechanical deformation to assess the effects of oxygen vacancy concentration and spatial distribution on domain switching. A Buckingham interatomic potential is employed to capture both t’-YSZ phase formation and ferroelastic domain switching. The results reveal that oxygen vacancy accumulation inhibits domain formation and suppresses ferroelastic reorientation via pinning effects, particularly near grain boundaries. These findings show that grain boundaries act as major sites of oxygen vacancy accumulation, with their structural geometry controlling how vacancies redistribute under compression and tension, thereby directly shaping the ferroelastic switching behavior of t’-YSZ.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118174"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118205
Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang
Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O6] octahedral site while preserving the rigid [GaO4] tetrahedral backbone in gallium-based olivine A2GaO4. A series of CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔSconfig) and ionic-size disorder (δR) drive a reversible Pnma → Pmnb symmetry switch, suppress phase separation, and expand the lattice. At x = 0.8, the high-entropy single-phase olivine exhibits εr = 9.2 ± 0.2, Q×f = 151,025 ± 400 GHz, and τf = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔSconfig, δR, and packing fraction. A C-band dielectric resonator antenna fabricated from the x = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.
{"title":"Entropy-driven design of ultra-low loss olivine CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 microwave dielectric ceramics for 5 G dielectric resonator antennas","authors":"Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang","doi":"10.1016/j.jeurceramsoc.2026.118205","DOIUrl":"10.1016/j.jeurceramsoc.2026.118205","url":null,"abstract":"<div><div>Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O<sub>6</sub>] octahedral site while preserving the rigid [GaO<sub>4</sub>] tetrahedral backbone in gallium-based olivine A<sub>2</sub>GaO<sub>4</sub>. A series of CaY<sub>1–<em>x</em></sub>(Nd<sub>0.25</sub>Sm<sub>0.25</sub>Eu<sub>0.25</sub>Yb<sub>0.25</sub>)<sub><em>x</em></sub>GaO<sub>4</sub> ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔS<sub>config</sub>) and ionic-size disorder (<em>δ</em><sub>R</sub>) drive a reversible <em>Pnma</em> → <em>Pmnb</em> symmetry switch, suppress phase separation, and expand the lattice. At <em>x</em> = 0.8, the high-entropy single-phase olivine exhibits <em>ε</em><sub><em>r</em></sub> = 9.2 ± 0.2, <em>Q×f</em> = 151,025 ± 400 GHz, and <em>τ</em><sub><em>f</em></sub> = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔS<sub>config</sub>, <em>δ</em><sub>R</sub>, and packing fraction. A C-band dielectric resonator antenna fabricated from the <em>x</em> = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118205"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-11DOI: 10.1016/j.ijrmhm.2026.107730
Xinu Tan , Yushun Liu , Risheng Qiu , Xuan Zhang , Liang Zhang , Jiateng Ma , Wangrui Ren , Feitao Li
Two types of orientation relationship (OR) Burgers and Potter can be observed during the phase transformation between the α and β phases in Zr alloys. In this work, electron back scatter diffraction and high-resolution transmission electron microscopy were carried out to characterize Potter OR in the solution-treated and subsequently annealed Zr alloys. Our results reveal the presence of Potter OR between parent β-Zr and {101}α twinning Martensite, elucidating the unique variant selection of {101} twins with in a single α-Zr grain in solution-treated samples. Significantly, a novel, non-stress induced, twinning mechanism was proposed via direct phase transformation based on Potter OR in Martensite. Upon annealing, the OR between β-Zr within the twinning Martensite and α-Zr retains Potter OR, independent of the element segregation at twin boundary. The occurrence of Potter OR instead of Burgers OR is attributed to the lower formation energy of Potter OR upon twinning based on our calculation. These results demonstrate an intrinsic association between Potter OR and the formation of {101} twins, shedding light on the designing of novel high-performance Zr alloys.
{"title":"Potter orientation relationship: The key to the origin of {101¯1} α martensitic twinning and the unusual β precipitation in Zr alloys","authors":"Xinu Tan , Yushun Liu , Risheng Qiu , Xuan Zhang , Liang Zhang , Jiateng Ma , Wangrui Ren , Feitao Li","doi":"10.1016/j.ijrmhm.2026.107730","DOIUrl":"10.1016/j.ijrmhm.2026.107730","url":null,"abstract":"<div><div>Two types of orientation relationship (OR) Burgers and Potter can be observed during the phase transformation between the α and β phases in Zr alloys. In this work, electron back scatter diffraction and high-resolution transmission electron microscopy were carried out to characterize Potter OR in the solution-treated and subsequently annealed Zr alloys. Our results reveal the presence of Potter OR between parent β-Zr and {10<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>1}<sub>α</sub> twinning Martensite, elucidating the unique variant selection of {10<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>1} twins with in a single α-Zr grain in solution-treated samples. Significantly, a novel, non-stress induced, twinning mechanism was proposed via direct phase transformation based on Potter OR in Martensite. Upon annealing, the OR between β-Zr within the twinning Martensite and α-Zr retains Potter OR, independent of the element segregation at twin boundary. The occurrence of Potter OR instead of Burgers OR is attributed to the lower formation energy of Potter OR upon twinning based on our calculation. These results demonstrate an intrinsic association between Potter OR and the formation of {10<span><math><mover><mn>1</mn><mo>¯</mo></mover></math></span>1} twins, shedding light on the designing of novel high-performance Zr alloys.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"138 ","pages":"Article 107730"},"PeriodicalIF":4.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146152749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-05DOI: 10.1016/j.ijrmhm.2026.107722
Tomila M. Vidyuk , Dina V. Dudina , Alexander I. Gavrilov , Arina V. Ukhina , Vladislav S. Shikalov , Igor S. Batraev , Sergey Yu. Usynin , Boris B. Bokhonov
In this study, in situ WC–Cu–based composites containing graphite were fabricated from a mixture of W, C(graphite) and Cu powders by high-energy mechanical milling and subsequent reactive spark plasma sintering (SPS). The synthesis of the carbides occurred during the SPS stage. In order to investigate the effect of graphite concentration on the structure and properties of the composites, the W–C(graphite)–Cu mixtures with three different molar ratios of elements (1:1:3, 1:1.3:3 and 1:1.7:3) were prepared. The graphite not converted into carbides remained unreacted in the sintered compacts. The combination of mechanical milling and SPS resulted in the formation of unconventional microstructures. The Cu-rich regions of re-solidified material are located between the composite areas, in which the WC and W2C particles are distributed uniformly. As the concentration of graphite was increased, the hardness and electrical conductivity of the composites decreased. The concentration of graphite in the composites influenced the morphology of the worn surfaces formed under dry sliding conditions. The WC–W2C–Cu-graphite composite (processing conditions: W–C(graphite)–3Cu mixture, 15 min of milling, SPS at 980 °C) shows an attractive combination of properties: a hardness of 250 HV, an electrical conductivity of 25% of the International Annealed Copper Standard, a residual porosity of less than 5%, a coefficient of friction of 0.58 in a pair with a WC-6Co ball, and a specific wear rate of 0.6 × 10−5 mm3 N−1 m−1.
{"title":"Microstructure and properties of spark plasma sintered WC–Cu–based in situ composites containing graphite","authors":"Tomila M. Vidyuk , Dina V. Dudina , Alexander I. Gavrilov , Arina V. Ukhina , Vladislav S. Shikalov , Igor S. Batraev , Sergey Yu. Usynin , Boris B. Bokhonov","doi":"10.1016/j.ijrmhm.2026.107722","DOIUrl":"10.1016/j.ijrmhm.2026.107722","url":null,"abstract":"<div><div>In this study, in situ WC–Cu–based composites containing graphite were fabricated from a mixture of W, C(graphite) and Cu powders by high-energy mechanical milling and subsequent reactive spark plasma sintering (SPS). The synthesis of the carbides occurred during the SPS stage. In order to investigate the effect of graphite concentration on the structure and properties of the composites, the W–C(graphite)–Cu mixtures with three different molar ratios of elements (1:1:3, 1:1.3:3 and 1:1.7:3) were prepared. The graphite not converted into carbides remained unreacted in the sintered compacts. The combination of mechanical milling and SPS resulted in the formation of unconventional microstructures. The Cu-rich regions of re-solidified material are located between the composite areas, in which the WC and W<sub>2</sub>C particles are distributed uniformly. As the concentration of graphite was increased, the hardness and electrical conductivity of the composites decreased. The concentration of graphite in the composites influenced the morphology of the worn surfaces formed under dry sliding conditions. The WC–W<sub>2</sub>C–Cu-graphite composite (processing conditions: W–C(graphite)–3Cu mixture, 15 min of milling, SPS at 980 °C) shows an attractive combination of properties: a hardness of 250 HV, an electrical conductivity of 25% of the International Annealed Copper Standard, a residual porosity of less than 5%, a coefficient of friction of 0.58 in a pair with a WC-6Co ball, and a specific wear rate of 0.6 × 10<sup>−5</sup> mm<sup>3</sup> N<sup>−1</sup> m<sup>−1</sup>.</div></div>","PeriodicalId":14216,"journal":{"name":"International Journal of Refractory Metals & Hard Materials","volume":"138 ","pages":"Article 107722"},"PeriodicalIF":4.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-03DOI: 10.1016/j.jeurceramsoc.2026.118207
Min-Soo Nam , Jin-Kwon Kim , Sahn Nahm , Seongwon Kim
Integrated Gasification Combined Cycle (IGCC) technology offers efficient and cleaner coal-based power generation but introduces corrosion challenges associated with high temperatures and molten slag. This study examines the corrosion behavior of ytterbium monosilicate (Yb₂SiO₅) and its composites containing 5 and 10 wt% Al₂O₃ under IGCC slag conditions. The addition of Al₂O₃ promotes the formation of garnet phases with higher thermal expansion, improving compatibility with the substrate. Samples exposed to molten slag were evaluated for microstructural evolution, thermal expansion, conductivity, and slag resistance. Yb₂SiO₅ exhibited high thermal stability and formed dense protective layers that limited slag infiltration. The composites enhanced thermal compatibility with carbon steel, increasing the coefficient of thermal expansion (CTE) to 9.8 × 10⁻⁶ and 10.9 × 10⁻⁶ K⁻¹ , respectively. The formation of a protective Yb₂Si₂O₇ layer underscores the potential of ytterbium silicates as effective high-temperature coatings for IGCC applications.
{"title":"Corrosion resistance of Yb-silicate materials to molten slag for protective coating applications","authors":"Min-Soo Nam , Jin-Kwon Kim , Sahn Nahm , Seongwon Kim","doi":"10.1016/j.jeurceramsoc.2026.118207","DOIUrl":"10.1016/j.jeurceramsoc.2026.118207","url":null,"abstract":"<div><div>Integrated Gasification Combined Cycle (IGCC) technology offers efficient and cleaner coal-based power generation but introduces corrosion challenges associated with high temperatures and molten slag. This study examines the corrosion behavior of ytterbium monosilicate (Yb₂SiO₅) and its composites containing 5 and 10 wt% Al₂O₃ under IGCC slag conditions. The addition of Al₂O₃ promotes the formation of garnet phases with higher thermal expansion, improving compatibility with the substrate. Samples exposed to molten slag were evaluated for microstructural evolution, thermal expansion, conductivity, and slag resistance. Yb₂SiO₅ exhibited high thermal stability and formed dense protective layers that limited slag infiltration. The composites enhanced thermal compatibility with carbon steel, increasing the coefficient of thermal expansion (CTE) to 9.8 × 10⁻⁶ and 10.9 × 10⁻⁶ K⁻¹ , respectively. The formation of a protective Yb₂Si₂O₇ layer underscores the potential of ytterbium silicates as effective high-temperature coatings for IGCC applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118207"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-08-01Epub Date: 2026-02-05DOI: 10.1016/j.jeurceramsoc.2026.118217
Yang Li , Yueming Li , Xintao Zhang , Xiujuan Chen , Li Tian , Jingjun Xu , Guorui Zhao
The durability of hypersonic structures is limited by catastrophic oxidation of conventional ultra-high temperature ceramics. Here, we investigate the oxidation of a novel high-entropy carbide, (5RE1/5)Al3C3, between 900 and 1300 °C, and reveal a multi-stage protection–failure mechanism that outperforms benchmark carbides. Oxidation begins with a transient amorphous RE–Al–C–O layer, which crystallizes into an ultra-dense nanocrystalline (5RE1/5)3Al5O12/Al2O3 scale, forming a robust diffusion barrier. Exceptional stability arises from a dual high-entropy effect: high configurational entropy in both the carbide and its oxide suppresses cation diffusion and arrests grain growth, maintaining protection up to 1200 °C. Even at 1300 °C, a dual-layer scale persists, with eventual linear-kinetic degradation governed by localized destabilization of the amorphous interlayer leading to microporosity, not catastrophic cracking. This work provides the first mechanistic evidence for dual high-entropy protection, establishing a new design principle for oxidation-resistant ceramics.
{"title":"Designing extreme-environment ceramics via a dual high-entropy protection strategy","authors":"Yang Li , Yueming Li , Xintao Zhang , Xiujuan Chen , Li Tian , Jingjun Xu , Guorui Zhao","doi":"10.1016/j.jeurceramsoc.2026.118217","DOIUrl":"10.1016/j.jeurceramsoc.2026.118217","url":null,"abstract":"<div><div>The durability of hypersonic structures is limited by catastrophic oxidation of conventional ultra-high temperature ceramics. Here, we investigate the oxidation of a novel high-entropy carbide, (5RE<sub>1/5</sub>)Al<sub>3</sub>C<sub>3</sub>, between 900 and 1300 °C, and reveal a multi-stage protection–failure mechanism that outperforms benchmark carbides. Oxidation begins with a transient amorphous RE–Al–C–O layer, which crystallizes into an ultra-dense nanocrystalline (5RE<sub>1/5</sub>)<sub>3</sub>Al<sub>5</sub>O<sub>12</sub>/Al<sub>2</sub>O<sub>3</sub> scale, forming a robust diffusion barrier. Exceptional stability arises from a dual high-entropy effect: high configurational entropy in both the carbide and its oxide suppresses cation diffusion and arrests grain growth, maintaining protection up to 1200 °C. Even at 1300 °C, a dual-layer scale persists, with eventual linear-kinetic degradation governed by localized destabilization of the amorphous interlayer leading to microporosity, not catastrophic cracking. This work provides the first mechanistic evidence for dual high-entropy protection, establishing a new design principle for oxidation-resistant ceramics.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118217"},"PeriodicalIF":6.2,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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