Pub Date : 2025-12-26DOI: 10.1016/j.matlet.2025.140008
D.I. Jimenez Remache, G. Abrosimova, A. Aronin
The phase transformations of the Co67Si12B9Fe7Nb5 amorphous alloy upon heating were studied by means of X-ray diffraction, and transmission electron microscopy. Upon annealing, a bcc Co-based phase was formed within the amorphous matrix. With increasing annealing temperature, stable phases such as Co16Nb6Si7, fcc Co, Co23B6, and Co2Si were found. The lattice parameter of the bcc Co-based phase was found to decrease with rising annealing temperature. An analysis based on Vegard's law indicates that the reduction in the lattice parameter of the bcc phase could be related to a temperature-dependent decrease in niobium concentration in a saturated solid solution containing cobalt, iron, and silicon.
{"title":"Phase transformations upon heating of amorphous Co67Si12B9Fe7Nb5 alloy","authors":"D.I. Jimenez Remache, G. Abrosimova, A. Aronin","doi":"10.1016/j.matlet.2025.140008","DOIUrl":"10.1016/j.matlet.2025.140008","url":null,"abstract":"<div><div>The phase transformations of the Co<sub>67</sub>Si<sub>12</sub>B<sub>9</sub>Fe<sub>7</sub>Nb<sub>5</sub> amorphous alloy upon heating were studied by means of X-ray diffraction, and transmission electron microscopy. Upon annealing, a bcc Co-based phase was formed within the amorphous matrix. With increasing annealing temperature, stable phases such as Co<sub>16</sub>Nb<sub>6</sub>Si<sub>7</sub>, fcc Co, Co<sub>23</sub>B<sub>6</sub>, and Co<sub>2</sub>Si were found. The lattice parameter of the bcc Co-based phase was found to decrease with rising annealing temperature. An analysis based on Vegard's law indicates that the reduction in the lattice parameter of the bcc phase could be related to a temperature-dependent decrease in niobium concentration in a saturated solid solution containing cobalt, iron, and silicon.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"407 ","pages":"Article 140008"},"PeriodicalIF":2.7,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Owing to the excellent mechanical, thermal, electrical properties and high specific surface area, porous copper (PCu)-based composite solder have attracted growing interest in third-generation semiconductor packaging. This paper proposed a method for preparing PCu based on high-temperature reduction and powder sintering. The prepared PCu featured a unique dual-continuous pore-ligament structure and excellent wettability for Sn96.5Ag0.3Cu0.5 (SAC305) solder to form P-Cu/SAC305 composite solder. After 30,000 power cycles at a constant junction temperature difference of 80 °C, the turn-on voltage of the SiC device packaged by P-Cu/SAC305 remained stable, and the thermal resistance of the device increased only from 2.40 K/W to 3.04 K/W.
{"title":"A novel method for fabricating dual-continuous pore-ligament porous copper and application in power device packaging","authors":"Jiahao Liu , Lijin Qiu , Jixi Huang , Dongyang Tian , Hongtao Chen , Hao Zhao","doi":"10.1016/j.matlet.2025.140005","DOIUrl":"10.1016/j.matlet.2025.140005","url":null,"abstract":"<div><div>Owing to the excellent mechanical, thermal, electrical properties and high specific surface area, porous copper (P<img>Cu)-based composite solder have attracted growing interest in third-generation semiconductor packaging. This paper proposed a method for preparing P<img>Cu based on high-temperature reduction and powder sintering. The prepared P<img>Cu featured a unique dual-continuous pore-ligament structure and excellent wettability for Sn<sub>96.5</sub>Ag<sub>0.3</sub>Cu<sub>0.5</sub> (SAC305) solder to form P-Cu/SAC305 composite solder. After 30,000 power cycles at a constant junction temperature difference of 80 °C, the turn-on voltage of the SiC device packaged by P-Cu/SAC305 remained stable, and the thermal resistance of the device increased only from 2.40 K/W to 3.04 K/W.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"407 ","pages":"Article 140005"},"PeriodicalIF":2.7,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145847541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-20DOI: 10.1016/j.matlet.2025.139993
Ju Hyang Park , Taeyeong Yun , Woo Seok Yang , Jun Young Ahn , Hyun Soo Ahn , Sungyeol Do , Juyoung Youn , Hyunjeong Han , Jun Sik Son
Researchers are extensively investigating chemical sensors that visually show acidic-gas exposure. Among various forms, fiber-type materials are highly versatile due to their wearability and flexibility. However, fibers manufactured by mixing halochromic dyes and polymers exhibit low mechanical strength owing to poor dye-polymer interaction. In this study, sheath/core(S/C)-structured fibers are fabricated, and their mechanical properties were evaluated based on the presence and location of the dye, along with their potential application as chemical sensors. While adding dye generally reduces mechanical strength, fibers with dye confined to the sheath show minimal deterioration. Moreover, compared with fibers containing dye throughout, sheath-dye fibers exhibit sufficient color change to visually indicate acid-gas exposure.
{"title":"Mechanical strength of sheath/core fibers containing halochromic dye and their use as colorimetric textile sensors exposed on acidic conditions","authors":"Ju Hyang Park , Taeyeong Yun , Woo Seok Yang , Jun Young Ahn , Hyun Soo Ahn , Sungyeol Do , Juyoung Youn , Hyunjeong Han , Jun Sik Son","doi":"10.1016/j.matlet.2025.139993","DOIUrl":"10.1016/j.matlet.2025.139993","url":null,"abstract":"<div><div>Researchers are extensively investigating chemical sensors that visually show acidic-gas exposure. Among various forms, fiber-type materials are highly versatile due to their wearability and flexibility. However, fibers manufactured by mixing halochromic dyes and polymers exhibit low mechanical strength owing to poor dye-polymer interaction. In this study, sheath/core(S/C)-structured fibers are fabricated, and their mechanical properties were evaluated based on the presence and location of the dye, along with their potential application as chemical sensors. While adding dye generally reduces mechanical strength, fibers with dye confined to the sheath show minimal deterioration. Moreover, compared with fibers containing dye throughout, sheath-dye fibers exhibit sufficient color change to visually indicate acid-gas exposure.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139993"},"PeriodicalIF":2.7,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-18DOI: 10.1016/j.matlet.2025.139982
Li-xin Xiang , De Dong , Yu-peng Lu , Guo-chao Gu , Hong-liang Zheng
To investigate the influence of Si content on the transition Sc-containing phases in AlSi alloys. Al-xSi-Mg-Sc-Zr-Ti alloys with varying Si contents (0–6.0 wt%) were prepared. The results demonstrate that a minor Si addition (0.5 wt%) promotes an increase in the number density of granular (Al, Si)3(Sc, Zr, Ti) precipitates within the Al matrix. Concurrently, the transformation of granular (Al, Si)3(Sc, Zr, Ti) particles into needle-shaped AlSi2(Sc, Zr, Ti)2 phases initiates at this composition and is completed upon the addition of 1.0 wt% Si. With further increasing Si content, the growth of the needle-shaped AlSi2(Sc, Zr, Ti)2 precipitates is markedly suppressed, resulting in a gradual reduction in their average size from ∼7.6 μm (1 wt% Si) to ∼2.7 μm (6.0 wt% Si). For mechanical property, as the Si content increases from 0 to 6.0 wt%, the ultimate tensile strength of the alloys significantly improves from 156 MPa to 423 MPa, the elongation decreases from 17.3 % to 7.4 %. This study reveals that Si additions not only facilitate the phase transformation of Sc-containing precipitates but also effectively enhance the mechanical strength of the alloys.
{"title":"Effect of Si content on the transformation of Sc-containing phases and mechanical properties in Al-xSi-Mg-Sc-Zr-Ti alloys","authors":"Li-xin Xiang , De Dong , Yu-peng Lu , Guo-chao Gu , Hong-liang Zheng","doi":"10.1016/j.matlet.2025.139982","DOIUrl":"10.1016/j.matlet.2025.139982","url":null,"abstract":"<div><div>To investigate the influence of Si content on the transition Sc-containing phases in Al<img>Si alloys. Al-xSi-Mg-Sc-Zr-Ti alloys with varying Si contents (0–6.0 wt%) were prepared. The results demonstrate that a minor Si addition (0.5 wt%) promotes an increase in the number density of granular (Al, Si)<sub>3</sub>(Sc, Zr, Ti) precipitates within the Al matrix. Concurrently, the transformation of granular (Al, Si)<sub>3</sub>(Sc, Zr, Ti) particles into needle-shaped AlSi<sub>2</sub>(Sc, Zr, Ti)<sub>2</sub> phases initiates at this composition and is completed upon the addition of 1.0 wt% Si. With further increasing Si content, the growth of the needle-shaped AlSi<sub>2</sub>(Sc, Zr, Ti)<sub>2</sub> precipitates is markedly suppressed, resulting in a gradual reduction in their average size from ∼7.6 μm (1 wt% Si) to ∼2.7 μm (6.0 wt% Si). For mechanical property, as the Si content increases from 0 to 6.0 wt%, the ultimate tensile strength of the alloys significantly improves from 156 MPa to 423 MPa, the elongation decreases from 17.3 % to 7.4 %. This study reveals that Si additions not only facilitate the phase transformation of Sc-containing precipitates but also effectively enhance the mechanical strength of the alloys.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139982"},"PeriodicalIF":2.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-17DOI: 10.1016/j.matlet.2025.139984
Sijie Zhang, Jiale Tian, Yinbao Tian, Jian Han
We present a rapid, cost-effective composition-screening strategy for WAAM-processed duplex stainless steels. By co-feeding ER2594 and Ni during GTAW-WAAM, we constructed an in-situ compositional gradient within a single 2594 DSS wall, enabling direct comparison of Ni levels under identical thermal histories. Joint electrochemical and microhardness measurements identify +4 wt% Ni as the best combined condition, with Icorr = 4.605 × 10−8 A·cm−2, Rct = 2.340 × 105 Ω·cm2, ΔEcorr = −0.175 V, and microhardness = 399 ± 38 HV0.2. These results demonstrate that this in-process gradient screen can rapidly delineate an optimal composition window without constructing multiple walls.
{"title":"Rapid screening of Ni addition in 2594 duplex stainless steel via in-situ gradient GTAW-WAAM","authors":"Sijie Zhang, Jiale Tian, Yinbao Tian, Jian Han","doi":"10.1016/j.matlet.2025.139984","DOIUrl":"10.1016/j.matlet.2025.139984","url":null,"abstract":"<div><div>We present a rapid, cost-effective composition-screening strategy for WAAM-processed duplex stainless steels. By co-feeding ER2594 and Ni during GTAW-WAAM, we constructed an in-situ compositional gradient within a single 2594 DSS wall, enabling direct comparison of Ni levels under identical thermal histories. Joint electrochemical and microhardness measurements identify +4 wt% Ni as the best combined condition, with I<sub>corr</sub> = 4.605 × 10<sup>−8</sup> A·cm<sup>−2</sup>, R<sub>ct</sub> = 2.340 × 10<sup>5</sup> Ω·cm<sup>2</sup>, ΔE<sub>corr</sub> = −0.175 V, and microhardness = 399 ± 38 HV<sub>0.2</sub>. These results demonstrate that this in-process gradient screen can rapidly delineate an optimal composition window without constructing multiple walls.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139984"},"PeriodicalIF":2.7,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study elucidates the microstructural evolution of the Co-free Al0.75CrFeNi1.5Cu0.5 high-entropy alloy (HEA) under four hot compression conditions via electron backscatter diffraction (EBSD). The results demonstrate a dual-phase (FCC + BCC) structure, with higher deformation temperatures promoting the transformation of BCC to FCC. At 1050 °C, the recrystallized grains were significantly refined to ∼1 μm. Continuous dynamic recrystallization (CDRX) was identified as the dominant recrystallization mechanism, accompanied by localized discontinuous dynamic recrystallization (DDRX). A novel finding is the superior recrystallization capacity of the BCC phase over the FCC phase under high temperature and high strain rate, a phenomenon seldom reported previously. Furthermore, a composite texture consisting of 〈1 0 0〉 and 〈1 1 1〉 developed at 1050 °C. These findings provide valuable guidance for the thermomechanical processing and property optimization of Al–Cr–Cu–Fe–Ni HEAs.
{"title":"Microstructural characteristics of Al0.75CrFeNi1.5Cu0.5 high-entropy alloy processed by hot compression","authors":"Yueran Jin , Chenhao Qian , Hengrui Shao , Xiangqian Zhu , Yulong Huang , Chaoyang Zhang","doi":"10.1016/j.matlet.2025.139975","DOIUrl":"10.1016/j.matlet.2025.139975","url":null,"abstract":"<div><div>This study elucidates the microstructural evolution of the Co-free Al<sub>0.75</sub>CrFeNi<sub>1.5</sub>Cu<sub>0.5</sub> high-entropy alloy (HEA) under four hot compression conditions via electron backscatter diffraction (EBSD). The results demonstrate a dual-phase (FCC + BCC) structure, with higher deformation temperatures promoting the transformation of BCC to FCC. At 1050 °C, the recrystallized grains were significantly refined to ∼1 μm. Continuous dynamic recrystallization (CDRX) was identified as the dominant recrystallization mechanism, accompanied by localized discontinuous dynamic recrystallization (DDRX). A novel finding is the superior recrystallization capacity of the BCC phase over the FCC phase under high temperature and high strain rate, a phenomenon seldom reported previously. Furthermore, a composite texture consisting of 〈1 0 0〉 and 〈1 1 1〉 developed at 1050 °C. These findings provide valuable guidance for the thermomechanical processing and property optimization of Al–Cr–Cu–Fe–Ni HEAs.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139975"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-16DOI: 10.1016/j.matlet.2025.139974
Vishnuvardhan Reddy Chappidi, Rajendra Kumar Challa, Sai Santosh Kumar Raavi
Perovskite solar cells (PSCs) are of significant interest due to their high efficiency and tunable optoelectronic properties, making them suitable for both outdoor and indoor applications. Here, we present a comparative analysis of PSC performance under AM 1.5G and compact fluorescent lamp (CFL) illumination, with a focus on the mechanisms governing device efficiency. While the external quantum efficiency (EQE) remains unchanged, the excess bandgap losses and recombination losses are significantly higher under CFL compared to AM 1.5G illumination. A pronounced decline in power conversion efficiency (PCE) is observed when the perovskite defect density exceeds 1 × 1015 cm−3, under both light sources. A device with the architecture ITO/SnO₂/Cs0.08(MA0.17FA0.83)0.92Pb(I0.83Br0.17)3/Spiro-OMeTAD/Ag demonstrates a PCE of 17.29 % under AM 1.5G and 29.9 % under CFL (3 W/m2). These findings offer key insights into the operational behaviour of PSCs under AM1.5G and CFL illumination.
{"title":"Comparative performance assessment of perovskite solar cells under AM 1.5G and CFL lighting conditions","authors":"Vishnuvardhan Reddy Chappidi, Rajendra Kumar Challa, Sai Santosh Kumar Raavi","doi":"10.1016/j.matlet.2025.139974","DOIUrl":"10.1016/j.matlet.2025.139974","url":null,"abstract":"<div><div>Perovskite solar cells (PSCs) are of significant interest due to their high efficiency and tunable optoelectronic properties, making them suitable for both outdoor and indoor applications. Here, we present a comparative analysis of PSC performance under AM 1.5G and compact fluorescent lamp (CFL) illumination, with a focus on the mechanisms governing device efficiency. While the external quantum efficiency (EQE) remains unchanged, the excess bandgap losses and recombination losses are significantly higher under CFL compared to AM 1.5G illumination. A pronounced decline in power conversion efficiency (PCE) is observed when the perovskite defect density exceeds 1 × 10<sup>15</sup> cm<sup>−3</sup>, under both light sources. A device with the architecture ITO/SnO₂/Cs<sub>0.08</sub>(MA<sub>0.17</sub>FA<sub>0.83</sub>)<sub>0.92</sub>Pb(I<sub>0.83</sub>Br<sub>0.17</sub>)<sub>3</sub>/Spiro-OMeTAD/Ag demonstrates a PCE of 17.29 % under AM 1.5G and 29.9 % under CFL (3 W/m<sup>2</sup>). These findings offer key insights into the operational behaviour of PSCs under AM1.5G and CFL illumination.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139974"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-16DOI: 10.1016/j.matlet.2025.139981
Yongqi Li , Yang Liu , Yifan Wang , Chengui Zhang , Jinlong Cui , Zhenxi Wang , Jinlu Zhu , Yalong Li , Qiang Wang
Copper submicronparticles have outstanding electrical and thermal conductivity, excellent weldability and relatively low cost. The two-step reduction method was adopted to systematically investigate the influencing factors, such as the type of copper source, and dispersants. Copper submicronparticles were characterized by UV–Vis, EDX, SEM, XRD, FTIR, and TEM. Moreover, copper submicronparticles are applied to conductive paste, and effect factors such as copper powder content have been investigated. The results shown that when the copper powder accounted for 70 wt% in the slurry, and the slurry was calcined at 800 °C in nitrogen atmosphere for 1 h, the conductive slurry exhibited a minimum resistivity of 3.98 × 10−6 Ω cm.
{"title":"Preparation of copper submicronparticles and application to conductive paste","authors":"Yongqi Li , Yang Liu , Yifan Wang , Chengui Zhang , Jinlong Cui , Zhenxi Wang , Jinlu Zhu , Yalong Li , Qiang Wang","doi":"10.1016/j.matlet.2025.139981","DOIUrl":"10.1016/j.matlet.2025.139981","url":null,"abstract":"<div><div>Copper submicronparticles have outstanding electrical and thermal conductivity, excellent weldability and relatively low cost. The two-step reduction method was adopted to systematically investigate the influencing factors, such as the type of copper source, and dispersants. Copper submicronparticles were characterized by UV–Vis, EDX, SEM, XRD, FTIR, and TEM. Moreover, copper submicronparticles are applied to conductive paste, and effect factors such as copper powder content have been investigated. The results shown that when the copper powder accounted for 70 wt% in the slurry, and the slurry was calcined at 800 °C in nitrogen atmosphere for 1 h, the conductive slurry exhibited a minimum resistivity of 3.98 × 10<sup>−6</sup> Ω cm.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139981"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972946","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of flexible ultraviolet photodetectors with high transparency, high hardness, foldability, excellent resilience, and superior scratch resistance has garnered considerable attention because of their broad applications in foldable-screen electronic devices, smart wearables, curved large displays, and in-vehicle displays. Herein, we design a novel type of flexible photodetector based on an ultra-thin flexible glass (UTG) substrate, which is renowned for its bendability and can withstand temperatures of up to 600 °C. The photodetector exhibits high switch ratios of 7 and 9.3, as well as short response/recovery times of 2 s/1.4 s and 0.7 s/1.6 s to 254 nm and 365 nm UV light, respectively. This study proposes a novel design for future high-performance photodetectors, thereby offering a promising avenue for the integration of flexible optoelectronic devices.
{"title":"Synthesis of SnO/SnO2 thin films for application in novel flexible ultraviolet photodetectors","authors":"Shumin Xing , Zihan Wu , Linyu Zhang , Qun Huang , Weigang Chen , Zhichao Liu , Yeguo Sun , Junfeng Chao","doi":"10.1016/j.matlet.2025.139958","DOIUrl":"10.1016/j.matlet.2025.139958","url":null,"abstract":"<div><div>The development of flexible ultraviolet photodetectors with high transparency, high hardness, foldability, excellent resilience, and superior scratch resistance has garnered considerable attention because of their broad applications in foldable-screen electronic devices, smart wearables, curved large displays, and in-vehicle displays. Herein, we design a novel type of flexible photodetector based on an ultra-thin flexible glass (UTG) substrate, which is renowned for its bendability and can withstand temperatures of up to 600 °C. The photodetector exhibits high switch ratios of 7 and 9.3, as well as short response/recovery times of 2 s/1.4 s and 0.7 s/1.6 s to 254 nm and 365 nm UV light, respectively. This study proposes a novel design for future high-performance photodetectors, thereby offering a promising avenue for the integration of flexible optoelectronic devices.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139958"},"PeriodicalIF":2.7,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2025-12-11DOI: 10.1016/j.matlet.2025.139953
Xi Wang , Weikang Ding , Hanpeng Gao , Shuangyu Liu
CoCrNiFeAl coatings reinforced with 20 wt% TiC were fabricated by laser additive manufacturing and subsequently annealed at different temperatures. XRD, DSC, and SEM analyses revealed the presence of TiC, FCC, and BCC phases in all coatings. Among them, the 610 °C annealed coating exhibited the highest FCC diffraction intensity, the densest microstructure, and a uniform dispersion of TiC particles. Tribological tests showed that the 610 °C coating achieved the lowest friction coefficient and wear loss, reduced by ∼30 % and ∼ 25 % compared with the 25 °C and 720 °C coatings, respectively. Worn surface observations indicated a smooth morphology with only shallow grooves and the formation of a compact, stable third-body layer that effectively suppressed further wear. Finite element simulations based on the Archard wear model successfully predicted the evolution of contact stress and wear behavior, showing a maximum equivalent stress of ∼40 MPa for the 610 °C coating, about 30 % lower than that of the as-deposited coating, in excellent agreement with experimental results. These findings demonstrate that annealing at 610 °C produces the optimal microstructure and tribological performance.
{"title":"Heat-treatment-induced microstructural evolution and wear behavior of CoCrNiFeAl–TiC coatings","authors":"Xi Wang , Weikang Ding , Hanpeng Gao , Shuangyu Liu","doi":"10.1016/j.matlet.2025.139953","DOIUrl":"10.1016/j.matlet.2025.139953","url":null,"abstract":"<div><div>CoCrNiFeAl coatings reinforced with 20 wt% TiC were fabricated by laser additive manufacturing and subsequently annealed at different temperatures. XRD, DSC, and SEM analyses revealed the presence of TiC, FCC, and BCC phases in all coatings. Among them, the 610 °C annealed coating exhibited the highest FCC diffraction intensity, the densest microstructure, and a uniform dispersion of TiC particles. Tribological tests showed that the 610 °C coating achieved the lowest friction coefficient and wear loss, reduced by ∼30 % and ∼ 25 % compared with the 25 °C and 720 °C coatings, respectively. Worn surface observations indicated a smooth morphology with only shallow grooves and the formation of a compact, stable third-body layer that effectively suppressed further wear. Finite element simulations based on the Archard wear model successfully predicted the evolution of contact stress and wear behavior, showing a maximum equivalent stress of ∼40 MPa for the 610 °C coating, about 30 % lower than that of the as-deposited coating, in excellent agreement with experimental results. These findings demonstrate that annealing at 610 °C produces the optimal microstructure and tribological performance.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139953"},"PeriodicalIF":2.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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