Pub Date : 2025-12-04DOI: 10.1016/j.matlet.2025.139912
Funsho Olaitan Kolawole , Elver Juan de Dios Mitma Pillaca , Gislene Valdete Martins , Shola Kolade Kolawole , Evaldo José Corat , Vladimir Jesus Trava-Airoldi
This study presents a novel method for incorporating graphene into diamond-like carbon (DLC) films using pulsed-DC plasma-enhanced chemical vapor deposition (PECVD) with an additional cathode. Unlike conventional PECVD methods, this approach enables direct in-situ incorporation of graphene into the DLC matrix via a glass-tube-assisted pulsed-valve system, ensuring uniform dispersion. The effects of graphene incorporation were examined by varying the glass-tube length. Results show that positioning the tube closer to the substrate holder enhances the DLC-graphene film properties, achieving a maximum hardness of 25.11 GPa and reducing the coefficient of friction to 0.0904. Additionally, a low wear rate of 1.03 × 10−6 mm3/N·m was obtained. A scalable single-step method producing uniform, adherent, and wear-resistant DLC-graphene coatings.
{"title":"New method for incorporating graphene into DLC film using pulsed-DC PECVD with an additional cathode","authors":"Funsho Olaitan Kolawole , Elver Juan de Dios Mitma Pillaca , Gislene Valdete Martins , Shola Kolade Kolawole , Evaldo José Corat , Vladimir Jesus Trava-Airoldi","doi":"10.1016/j.matlet.2025.139912","DOIUrl":"10.1016/j.matlet.2025.139912","url":null,"abstract":"<div><div>This study presents a novel method for incorporating graphene into diamond-like carbon (DLC) films using pulsed-DC plasma-enhanced chemical vapor deposition (PECVD) with an additional cathode. Unlike conventional PECVD methods, this approach enables direct in-situ incorporation of graphene into the DLC matrix via a glass-tube-assisted pulsed-valve system, ensuring uniform dispersion. The effects of graphene incorporation were examined by varying the glass-tube length. Results show that positioning the tube closer to the substrate holder enhances the DLC-graphene film properties, achieving a maximum hardness of 25.11 GPa and reducing the coefficient of friction to 0.0904. Additionally, a low wear rate of 1.03 × 10<sup>−6</sup> mm<sup>3</sup>/N·m was obtained. A scalable single-step method producing uniform, adherent, and wear-resistant DLC-graphene coatings.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139912"},"PeriodicalIF":2.7,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682192","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 : 2025-12-04DOI: 10.1016/j.matlet.2025.139908
Feiyang Xiang , Fengling Ran , Qing Liu , Chuanli Zhao , Guodong Zhao
To address lead - zinc tailings accumulation, this study used lead - zinc tailings and metakaolin as precursors in a geopolymer reaction system to prepare geopolymer slurry. The optimal mix proportion was determined via mix proportioning, freeze–thaw cycling. XRD and SEM were used to characterize phase composition and microstructure. Based on this, the frost resistance of the lead–zinc tailings–based geopolymer paste was evaluated, and its structural stability, durability, safety, and mechanical performance variations under low - temperature conditions were verified, providing a foundation for its long-term engineering application in cold environments. The results showed that considering freeze - thaw resistance and lead - zinc tailings powder utilization rate, the optimal dosage of the powder was 40 %. Under this condition, the compressive strengths of the slurry specimens at 3d, 7d, 14d, and 28d were 47.69 MPa, 83.23 MPa, 90.62 MPa, and 71.69 MPa respectively. After 125 freeze - thaw cycles, the strength loss rate and relative strength loss rate were 14.8 %, indicating excellent freeze - thaw resistance
{"title":"Preparation and frost resistance of lead–zinc tailings geopolymer slurry","authors":"Feiyang Xiang , Fengling Ran , Qing Liu , Chuanli Zhao , Guodong Zhao","doi":"10.1016/j.matlet.2025.139908","DOIUrl":"10.1016/j.matlet.2025.139908","url":null,"abstract":"<div><div>To address lead - zinc tailings accumulation, this study used lead - zinc tailings and metakaolin as precursors in a geopolymer reaction system to prepare geopolymer slurry. The optimal mix proportion was determined via mix proportioning, freeze–thaw cycling. XRD and SEM were used to characterize phase composition and microstructure. Based on this, the frost resistance of the lead–zinc tailings–based geopolymer paste was evaluated, and its structural stability, durability, safety, and mechanical performance variations under low - temperature conditions were verified, providing a foundation for its long-term engineering application in cold environments. The results showed that considering freeze - thaw resistance and lead - zinc tailings powder utilization rate, the optimal dosage of the powder was 40 %. Under this condition, the compressive strengths of the slurry specimens at 3d, 7d, 14d, and 28d were 47.69 MPa, 83.23 MPa, 90.62 MPa, and 71.69 MPa respectively. After 125 freeze - thaw cycles, the strength loss rate and relative strength loss rate were 14.8 %, indicating excellent freeze - thaw resistance</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139908"},"PeriodicalIF":2.7,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682130","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 : 2025-12-04DOI: 10.1016/j.matlet.2025.139906
Meng-Ge Yao , Su-Juan Zhong , Quan-Bin Lu , Bao Wang , Peng Guo , Da-Shuang Liu , Dan-Dan Guo
Rare earth (RE) elements exhibit high chemical reactivity, engaging in complex interactions with brazing filler metal compositions, thereby posing significant challenges for brazing Al-RE casting alloys. This study innovatively employed Ni-modified AlSi brazing filler metals to achieve brazing connections in Al-Ce-La cast alloys. It focused on investigating the micro-interaction mechanisms between Ni and rare earth elements, while systematically analysing the effects of Al-Si-Ni brazing filler metals with varying Ni contents on microstructural evolution and mechanical properties within brazed joints. Results indicate that increasing Ni content in the flux effectively suppresses the formation of coarse needle-like rare earth phases within the brazed joint. Concurrently, it promotes the precipitation of Al3Ni phases and generates granular intermetallic compounds, primarily La2NiAl7 and Al5CeNi, at the interface. The synergistic effects of these microstructures substantially enhance the bonding strength of the brazed joint.
{"title":"Novel brazing of Al-Ce-La cast aluminium alloys with Ni-modified Al-Si filler metals: Interface regulation and strengthening mechanism","authors":"Meng-Ge Yao , Su-Juan Zhong , Quan-Bin Lu , Bao Wang , Peng Guo , Da-Shuang Liu , Dan-Dan Guo","doi":"10.1016/j.matlet.2025.139906","DOIUrl":"10.1016/j.matlet.2025.139906","url":null,"abstract":"<div><div>Rare earth (RE) elements exhibit high chemical reactivity, engaging in complex interactions with brazing filler metal compositions, thereby posing significant challenges for brazing Al-RE casting alloys. This study innovatively employed Ni-modified Al<img>Si brazing filler metals to achieve brazing connections in Al-Ce-La cast alloys. It focused on investigating the micro-interaction mechanisms between Ni and rare earth elements, while systematically analysing the effects of Al-Si-Ni brazing filler metals with varying Ni contents on microstructural evolution and mechanical properties within brazed joints. Results indicate that increasing Ni content in the flux effectively suppresses the formation of coarse needle-like rare earth phases within the brazed joint. Concurrently, it promotes the precipitation of Al<sub>3</sub>Ni phases and generates granular intermetallic compounds, primarily La<sub>2</sub>NiAl<sub>7</sub> and Al<sub>5</sub>CeNi, at the interface. The synergistic effects of these microstructures substantially enhance the bonding strength of the brazed joint.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139906"},"PeriodicalIF":2.7,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682191","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 : 2025-12-03DOI: 10.1016/j.matlet.2025.139905
Li Liu, Shuo Liu, Hao Cao, Jingxia Xie, Zhixian Jiao, Qingzhou Wang
The Zn22Al (ZA22) alloy, despite its high damping capacity, has poor mechanical properties, limiting its use in high-load applications. This study addresses this problem by combining Li incorporation and hot rolling. Li segregates at Zn/Al interfaces, suppressing interdiffusion and promoting a unique multi-layer structure containing layered α phase, lamellar and granular eutectoid structures, as well as (η + LiZn4) eutectic structure. Hot rolling induces dynamic recrystallization, refining the η phase and eutectoid structure while work-hardening in α phase. These changes enhance both strength and damping. The optimal specimen with 0.7 wt % Li shows an ultimate tensile strength of 438 MPa (an 86 % increase), 25 % elongation, and a damping capacity of 0.054 at 40 °C (a 33 % increase).
{"title":"Synergistic enhancement of tensile strength and damping property in ZA22 alloy through lithium incorporation and hot rolling","authors":"Li Liu, Shuo Liu, Hao Cao, Jingxia Xie, Zhixian Jiao, Qingzhou Wang","doi":"10.1016/j.matlet.2025.139905","DOIUrl":"10.1016/j.matlet.2025.139905","url":null,"abstract":"<div><div>The Zn<img>22Al (ZA22) alloy, despite its high damping capacity, has poor mechanical properties, limiting its use in high-load applications. This study addresses this problem by combining Li incorporation and hot rolling. Li segregates at Zn/Al interfaces, suppressing interdiffusion and promoting a unique multi-layer structure containing layered α phase, lamellar and granular eutectoid structures, as well as (η + LiZn<sub>4</sub>) eutectic structure. Hot rolling induces dynamic recrystallization, refining the η phase and eutectoid structure while work-hardening in α phase. These changes enhance both strength and damping. The optimal specimen with 0.7 wt % Li shows an ultimate tensile strength of 438 MPa (an 86 % increase), 25 % elongation, and a damping capacity of 0.054 at 40 °C (a 33 % increase).</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139905"},"PeriodicalIF":2.7,"publicationDate":"2025-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682271","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}
BiFeO3 powders synthesized via solid-state reaction from Bi2O3 and Fe2O3 often contain secondary phases and coarse grains, which degrade their magnetic properties. This study demonstrates a novel solid-state method using ball milling of Bi and Fe powders followed by oxidation. After 10 h of milling, fine particles were formed with an amorphous iron oxide coating on Bi. A rapid 2 min oxidation at 800 °C produced BiFeO3 with a flower-like morphology. Electron spin resonance (ESR) analysis indicated Fe3+ paramagnetic centers and variation in the spin environment with milling duration. The powders showed a saturation magnetization (Ms) of ∼11 emu/g. The enhanced magnetization was attributed to morphology rather than local spin disorder.
{"title":"Synthesis of BiFeO3 powders with remarkably high magnetization via novel solid-state route","authors":"Ch. Sree Rama Linga Prasad , H. Seshagiri Rao , B.S. Murty , Srinivasa Rao Bakshi","doi":"10.1016/j.matlet.2025.139904","DOIUrl":"10.1016/j.matlet.2025.139904","url":null,"abstract":"<div><div>BiFeO<sub>3</sub> powders synthesized via solid-state reaction from Bi<sub>2</sub>O<sub>3</sub> and Fe<sub>2</sub>O<sub>3</sub> often contain secondary phases and coarse grains, which degrade their magnetic properties. This study demonstrates a novel solid-state method using ball milling of Bi and Fe powders followed by oxidation. After 10 h of milling, fine particles were formed with an amorphous iron oxide coating on Bi. A rapid 2 min oxidation at 800 °C produced BiFeO<sub>3</sub> with a flower-like morphology. Electron spin resonance (ESR) analysis indicated Fe<sup>3+</sup> paramagnetic centers and variation in the spin environment with milling duration. The powders showed a saturation magnetization (M<sub>s</sub>) of ∼11 emu/g. The enhanced magnetization was attributed to morphology rather than local spin disorder.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139904"},"PeriodicalIF":2.7,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682189","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 : 2025-12-02DOI: 10.1016/j.matlet.2025.139903
Jayakumar Venugopal, Giriraj Mannayee
The paper focused on dry sliding wear tests of AZ31 alloy reinforced with titanium boride (TiB2) conducted by pin-on-disc arrangement at ambient temperature. The AZ31/ TiB2 composites were manufactured by ultrasonic-assisted squeeze casting to conduct wear analysis under various normal loads (10 N, 20 N, and 30 N) at a constant sliding distance. The coefficient of friction and specific wear rate decreased due to the combination of increased reinforcement percentage and enhanced hardness. The inverse pole figure (IPF) maps showed a decrease in texture intensity, while the kernel average misorientation (KAM) maps indicated an enhance the strain relocation capacity, and the average grain size reduced to approximately 16 μm in the AZ31/ TiB2 (5 %) composite. Field-emission scanning electron microscopy was used to analyse the morphology of the wear surface under various test conditions, including plastic deformation, abrasive wear, delamination, oxide formation, and wear debris. In this, AZ31/ TiB2 (5 %) exhibits improved hardness of about 58.59 %, decreased specific wear rate, and COF of 64.15 % and 25.71 % compared to AZ31 alloy.
{"title":"Influence of titanium boride particles on the tribological behaviour of Mg-AZ31 composite","authors":"Jayakumar Venugopal, Giriraj Mannayee","doi":"10.1016/j.matlet.2025.139903","DOIUrl":"10.1016/j.matlet.2025.139903","url":null,"abstract":"<div><div>The paper focused on dry sliding wear tests of AZ31 alloy reinforced with titanium boride (TiB<sub>2</sub>) conducted by pin-on-disc arrangement at ambient temperature. The AZ31/ TiB<sub>2</sub> composites were manufactured by ultrasonic-assisted squeeze casting to conduct wear analysis under various normal loads (10 N, 20 N, and 30 N) at a constant sliding distance. The coefficient of friction and specific wear rate decreased due to the combination of increased reinforcement percentage and enhanced hardness. The inverse pole figure (IPF) maps showed a decrease in texture intensity, while the kernel average misorientation (KAM) maps indicated an enhance the strain relocation capacity, and the average grain size reduced to approximately 16 μm in the AZ31/ TiB<sub>2</sub> (5 %) composite. Field-emission scanning electron microscopy was used to analyse the morphology of the wear surface under various test conditions, including plastic deformation, abrasive wear, delamination, oxide formation, and wear debris. In this, AZ31/ TiB<sub>2</sub> (5 %) exhibits improved hardness of about 58.59 %, decreased specific wear rate, and COF of 64.15 % and 25.71 % compared to AZ31 alloy.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139903"},"PeriodicalIF":2.7,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682263","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 : 2025-12-01DOI: 10.1016/j.matlet.2025.139899
Denghao Yi , Dongyun Zhang , Xiaofeng Li
In this study, AlSi10Mg-10wt%SiC-0.5wt%LaB6 composites are successfully fabricated via laser powder bed fusion (LPBF). The LPBF processing window is systematically explored, and a quantitative correlation is established between the processing window and SiC area fraction. Concurrently, the morphological characteristics and evolution mechanism of SiC particles are analyzed. It is found that the differential melting-diffusion reactions of SiC particles (directly related to the laser interaction positions) are the key factors regulating their interfacial morphology. This study provides critical theoretical references for the application of Al-SiC composites in the field of structural-material integration.
{"title":"Evolution mechanism of SiC particles in LPBF-fabricated AlSi10Mg-10SiC-0.5LaB6 composites","authors":"Denghao Yi , Dongyun Zhang , Xiaofeng Li","doi":"10.1016/j.matlet.2025.139899","DOIUrl":"10.1016/j.matlet.2025.139899","url":null,"abstract":"<div><div>In this study, AlSi10Mg-10wt%SiC-0.5wt%LaB<sub>6</sub> composites are successfully fabricated via laser powder bed fusion (LPBF). The LPBF processing window is systematically explored, and a quantitative correlation is established between the processing window and SiC area fraction. Concurrently, the morphological characteristics and evolution mechanism of SiC particles are analyzed. It is found that the differential melting-diffusion reactions of SiC particles (directly related to the laser interaction positions) are the key factors regulating their interfacial morphology. This study provides critical theoretical references for the application of Al-SiC composites in the field of structural-material integration.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139899"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733992","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 : 2025-12-01DOI: 10.1016/j.matlet.2025.139838
Vignesh V. , Sudheer Reddy Beyanagari , R. Vaira Vignesh , M. Govindaraju , B. Venkataraman , Anil Kumar
This study introduces a novel vacuum arc brazing technique employing TC4 foil as the filler material to join Ti6Al4V and SiC. Brazing was performed in a high-vacuum chamber (pressure < 10−2 mbar) under an argon atmosphere at a temperature of 1650 °C with a dwell time of 30 s. The Ti6Al4V||SiC interface formed a robust, seamless joint with no gaps, showcasing an excellent wettability of Ti6Al4V on the SiC surface. Microanalysis revealed Ti diffusion into the SiC, leading to partial breakdown and the formation of TiC phases, which was also confirmed from the phase composition. Due to the presence of these hard phases, the interface showed a hardness of 1833 ± 40.3 HV.
{"title":"Microstructural evolution of dissimilar Ti6Al4V||SiC joints fabricated by innovative vacuum arc brazing","authors":"Vignesh V. , Sudheer Reddy Beyanagari , R. Vaira Vignesh , M. Govindaraju , B. Venkataraman , Anil Kumar","doi":"10.1016/j.matlet.2025.139838","DOIUrl":"10.1016/j.matlet.2025.139838","url":null,"abstract":"<div><div>This study introduces a novel vacuum arc brazing technique employing TC4 foil as the filler material to join Ti6Al4V and SiC. Brazing was performed in a high-vacuum chamber (pressure < 10<sup>−2</sup> mbar) under an argon atmosphere at a temperature of 1650 °C with a dwell time of 30 s. The Ti6Al4V||SiC interface formed a robust, seamless joint with no gaps, showcasing an excellent wettability of Ti6Al4V on the SiC surface. Microanalysis revealed Ti diffusion into the SiC, leading to partial breakdown and the formation of TiC phases, which was also confirmed from the phase composition. Due to the presence of these hard phases, the interface showed a hardness of 1833 ± 40.3 HV.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139838"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682268","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 : 2025-12-01DOI: 10.1016/j.matlet.2025.139898
Xiaoming Cui , Dongxu Sun , Fei Liu, Xiaohu Hou, Xueping Zhao, Pucun Bai, Xiangqian Liu
The microscopic structure and strain field of Al2Ca laves phase was observed in a spray forming extrusive Mg-12Al-1.5Zn-6.5Ca-1.0Nd alloy by using the geometrical phase analysis (GPA) techniques based on high-resolution transmission electron microscopy (HRTEM). Then, JEMS and Crystal Maker software were used through focus exit wave reconstruction (TF-EWR) of HRTEM images. The extrinsic stacking faults (ESF) and twin structure of Al2Ca Laves phase can be observed by filtering and reconstructing the HRTEM images. There is obvious lattice distortion at the stacking fault interface. This phenomenon is caused by synchroshear between different slip planes. The strain fields calculated indicate that the strain peak value of lattice distortion at the ESF is about 2.85 %, larger than that at the twin. Finally, the synchroshear deformation mechanism of the Al2Ca crystal structure is discussed. These experimental results expand the understanding of Al2Ca phase structure in Mg-12Al-1.5Zn-6.5Ca-1.0Nd alloys.
{"title":"The synchroshear mechanism and strain field of stacking faults and twins in Al2Ca laves phase","authors":"Xiaoming Cui , Dongxu Sun , Fei Liu, Xiaohu Hou, Xueping Zhao, Pucun Bai, Xiangqian Liu","doi":"10.1016/j.matlet.2025.139898","DOIUrl":"10.1016/j.matlet.2025.139898","url":null,"abstract":"<div><div>The microscopic structure and strain field of Al<sub>2</sub>Ca laves phase was observed in a spray forming extrusive Mg-12Al-1.5Zn-6.5Ca-1.0Nd alloy by using the geometrical phase analysis (GPA) techniques based on high-resolution transmission electron microscopy (HRTEM). Then, JEMS and Crystal Maker software were used through focus exit wave reconstruction (TF-EWR) of HRTEM images. The extrinsic stacking faults (ESF) and twin structure of Al<sub>2</sub>Ca Laves phase can be observed by filtering and reconstructing the HRTEM images. There is obvious lattice distortion at the stacking fault interface. This phenomenon is caused by synchroshear between different slip planes. The strain fields calculated indicate that the strain peak value of lattice distortion at the ESF is about 2.85 %, larger than that at the twin. Finally, the synchroshear deformation mechanism of the Al<sub>2</sub>Ca crystal structure is discussed. These experimental results expand the understanding of Al<sub>2</sub>Ca phase structure in Mg-12Al-1.5Zn-6.5Ca-1.0Nd alloys.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139898"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682205","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 : 2025-12-01DOI: 10.1016/j.matlet.2025.139901
Wenhua Yang, Jing Wang, Chao Xie, Zhixiang Huang
To realize Cu–Cu low temperature direct bonding for 3D ICs manufacturing, a mixed gas of ammonia and nitrogen was used to reduce Cu surface oxide before bonding. At 220 °C, Cu surface oxide undergoes effective reduction, with minimal nitrogen residue remaining on the Cu surface, which is negligible for bonding. The Cu–Cu direct bonding was realized at 220 °C after ammonia treatment. The bonding strength increases from 11.5 MPa to 34.2 MPa as the bonding time increases from 10 min to 30 min. Additionally, the contact resistance at the bonding interface decreases from 198 mΩ to 109 mΩ, representing a 45 % reduction. The bonding interface, when subjected to a temperature of 220 °C for 30 min, remains continuous without voids or gaps, demonstrating its outstanding mechanical and electrical properties.
{"title":"High-performance low-temperature Cu–Cu direct bonding in an ammonia/N2 mixed atmosphere","authors":"Wenhua Yang, Jing Wang, Chao Xie, Zhixiang Huang","doi":"10.1016/j.matlet.2025.139901","DOIUrl":"10.1016/j.matlet.2025.139901","url":null,"abstract":"<div><div>To realize Cu–Cu low temperature direct bonding for 3D ICs manufacturing, a mixed gas of ammonia and nitrogen was used to reduce Cu surface oxide before bonding. At 220 °C, Cu surface oxide undergoes effective reduction, with minimal nitrogen residue remaining on the Cu surface, which is negligible for bonding. The Cu–Cu direct bonding was realized at 220 °C after ammonia treatment. The bonding strength increases from 11.5 MPa to 34.2 MPa as the bonding time increases from 10 min to 30 min. Additionally, the contact resistance at the bonding interface decreases from 198 mΩ to 109 mΩ, representing a 45 % reduction. The bonding interface, when subjected to a temperature of 220 °C for 30 min, remains continuous without voids or gaps, demonstrating its outstanding mechanical and electrical properties.</div></div>","PeriodicalId":384,"journal":{"name":"Materials Letters","volume":"406 ","pages":"Article 139901"},"PeriodicalIF":2.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682188","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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