Pub Date : 2025-01-08DOI: 10.1016/j.jmrt.2025.01.051
Fei Chen , Xiaobo Sun , Bin Fang , Ke Yan , Bei Yan
Si3N4 ceramic bearings have demonstrated significant potential in augmenting the performance of liquid rockets. However, the operational conditions, including reciprocating use, ultra-high-speeds, and high-load impacts, impose more stringent requirements on their self-lubricating performance. Consequently, the cryogenic tribological properties of Si3N4 ceramic composites with hybrid of multilayer graphene (MLG) and β-Si3N4 whisker (β-Si3N4w) were thoroughly investigated in this work. The enhanced interatomic binding energy and friction-induced thermal diffusion were identified as contributing factors to the improved low-temperature tribological properties of Si3N4 ceramic composites. At a temperature of 77 K, the friction coefficient of Si3N4 ceramic composites containing 1 wt% MLG and 3 wt% β-Si3N4w, synthesized via spark plasma sintering, dropped to 0.16–0.20, representing a decrease of 39.39–44.83% compared to that at ambient temperature. Microscopic analysis of the worn surfaces indicated that adhesive wear was the predominant wear form for Si3N4 ceramic composites under low-temperature conditions. The above research is anticipated to furnish essential insights for the cryogenic self-lubricating design of ceramic composites.
{"title":"Low-temperature tribological properties of Si3N4 ceramic composites incorporating nano/microscale graphene and Si3N4 whisker","authors":"Fei Chen , Xiaobo Sun , Bin Fang , Ke Yan , Bei Yan","doi":"10.1016/j.jmrt.2025.01.051","DOIUrl":"10.1016/j.jmrt.2025.01.051","url":null,"abstract":"<div><div>Si<sub>3</sub>N<sub>4</sub> ceramic bearings have demonstrated significant potential in augmenting the performance of liquid rockets. However, the operational conditions, including reciprocating use, ultra-high-speeds, and high-load impacts, impose more stringent requirements on their self-lubricating performance. Consequently, the cryogenic tribological properties of Si<sub>3</sub>N<sub>4</sub> ceramic composites with hybrid of multilayer graphene (MLG) and β-Si<sub>3</sub>N<sub>4</sub> whisker (β-Si<sub>3</sub>N<sub>4w</sub>) were thoroughly investigated in this work. The enhanced interatomic binding energy and friction-induced thermal diffusion were identified as contributing factors to the improved low-temperature tribological properties of Si<sub>3</sub>N<sub>4</sub> ceramic composites. At a temperature of 77 K, the friction coefficient of Si<sub>3</sub>N<sub>4</sub> ceramic composites containing 1 wt% MLG and 3 wt% β-Si<sub>3</sub>N<sub>4w</sub>, synthesized via spark plasma sintering, dropped to 0.16–0.20, representing a decrease of 39.39–44.83% compared to that at ambient temperature. Microscopic analysis of the worn surfaces indicated that adhesive wear was the predominant wear form for Si<sub>3</sub>N<sub>4</sub> ceramic composites under low-temperature conditions. The above research is anticipated to furnish essential insights for the cryogenic self-lubricating design of ceramic composites.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 325-331"},"PeriodicalIF":6.2,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.030
Yuanhong Qian , Liangxian Gu , Rong Chen , Haiou Yang , Zhiyong Li , Zhaowen Cui , Shuya Zhang
In this study, the effect of solution and aging heat treatments on the microstructure and mechanical properties of GH4099 superalloy fabricated lase powder bed fusion (L-PBF) was investigated.The microstructure of as-manufactured L-PBF-built GH4099 alloy has elongation grain with an average grain size of 33.8 μm and fine cellular dendrites with an average spacing of 400 nm along the building direction. The grain structure of L-PBF-built GH4099 alloy is relatively complex and the grain boundary morphology is irregular. The morphology factor of the grains in the as-built GH4099 alloy primarily ranges between 0.3 and 0.4, with a notable inverse relationship between grain size and morphology factor. The L-PBF-built GH4099 alloy underwent complete recrystallization recrystallization when the solution temperature is 1120 °C and the holding time is extended to 4 h. With an increase in the solution temperature, the time required for complete recrystallization decreases progressively. As epitaxial columnar crystals are progressively replaced by recrystallized grains, the correlation between grain size and morphology factor gradually diminishes. The selection of solution and aging treatment parameters is based on the established relationships between the minimum solution time, temperature, and recrystallization behavior as well as the aging time, temperature, and hardness. The hardness of the fully recrystallized sample reached 460HV after solution at 1140 °C for 2 h and aging at 800 °C for 6 h, while the non-fully recrystallized sample reached 470HV after solution at 1120 °C for 1 h and aging at 750 °C for 8 h.The optimal heat treatment system of L-PBF-built GH4099 alloy is solid solution at 1140 °C for 2h, then aging at 800 for 6h. Under the optimal heat treatment regime, the longitudinal and transverse specimens have yield strengths of 714 and 753 MPa, tensile strengths of 1197 and 1230 MPa, and elongations of 45.3% and 38.9%, respectively.
{"title":"Effect of heat treatment on the microstructural evolution and mechanical properties of GH4099 fabricated by lase powder bed fusion","authors":"Yuanhong Qian , Liangxian Gu , Rong Chen , Haiou Yang , Zhiyong Li , Zhaowen Cui , Shuya Zhang","doi":"10.1016/j.jmrt.2025.01.030","DOIUrl":"10.1016/j.jmrt.2025.01.030","url":null,"abstract":"<div><div>In this study, the effect of solution and aging heat treatments on the microstructure and mechanical properties of GH4099 superalloy fabricated lase powder bed fusion (L-PBF) was investigated.The microstructure of as-manufactured L-PBF-built GH4099 alloy has elongation grain with an average grain size of 33.8 μm and fine cellular dendrites with an average spacing of 400 nm along the building direction. The grain structure of L-PBF-built GH4099 alloy is relatively complex and the grain boundary morphology is irregular. The morphology factor of the grains in the as-built GH4099 alloy primarily ranges between 0.3 and 0.4, with a notable inverse relationship between grain size and morphology factor. The L-PBF-built GH4099 alloy underwent complete recrystallization recrystallization when the solution temperature is 1120 °C and the holding time is extended to 4 h. With an increase in the solution temperature, the time required for complete recrystallization decreases progressively. As epitaxial columnar crystals are progressively replaced by recrystallized grains, the correlation between grain size and morphology factor gradually diminishes. The selection of solution and aging treatment parameters is based on the established relationships between the minimum solution time, temperature, and recrystallization behavior as well as the aging time, temperature, and hardness. The hardness of the fully recrystallized sample reached 460HV after solution at 1140 °C for 2 h and aging at 800 °C for 6 h, while the non-fully recrystallized sample reached 470HV after solution at 1120 °C for 1 h and aging at 750 °C for 8 h.The optimal heat treatment system of L-PBF-built GH4099 alloy is solid solution at 1140 °C for 2h, then aging at 800 for 6h. Under the optimal heat treatment regime, the longitudinal and transverse specimens have yield strengths of 714 and 753 MPa, tensile strengths of 1197 and 1230 MPa, and elongations of 45.3% and 38.9%, respectively.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 1126-1140"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.039
Qingzhong Song , Xiangdong Zha , Junjie Shi , Ming Gao , Yingche Ma
MgO refractories extensively applied in melting nickel-based superalloys are limited by their poor thermal shock resistance and susceptibility to melt erosion. This study regulated the phase composition of MgO refractories by doping TiO2 to improve their properties and corrosion resistance. It was found that TiO2 is an effective dopant, addressing key limitations such as hard sintering, inadequate thermal shock resistance, and insufficient chemical stability. Firstly, the strong sintering ability of TiO2 promoted the densification of MgO crucibles by generating a liquid phase composed of TiO2–MgO–CaO–SiO2, resulting in a significant reduction in open porosity from 12.62% to 9.76% at a doping level of 5 wt%. Moreover, TiO2 alters the initial bonding phase from Ca2SiO4 into CaTiO3, Mg2SiO4, and Mg2TiO4, enhancing thermal shock resistance by generating microcracks, lowering thermal expansion coefficient, and detaching the matrix/aggregate bonding. Notably, adding TiO2 enhanced the corrosion resistance of MgO ceramic crucibles, reducing the total impurity content in the alloy from 0.0021 wt% to 0.0007 wt%. In summary, TiO2-doped MgO crucibles demonstrated superior performance compared to pure MgO and MgAl2O4 crucibles.
{"title":"Development of TiO2-doped MgO refractories with enhanced corrosion resistance for preparing high-purity nickel-based superalloys","authors":"Qingzhong Song , Xiangdong Zha , Junjie Shi , Ming Gao , Yingche Ma","doi":"10.1016/j.jmrt.2025.01.039","DOIUrl":"10.1016/j.jmrt.2025.01.039","url":null,"abstract":"<div><div>MgO refractories extensively applied in melting nickel-based superalloys are limited by their poor thermal shock resistance and susceptibility to melt erosion. This study regulated the phase composition of MgO refractories by doping TiO<sub>2</sub> to improve their properties and corrosion resistance. It was found that TiO<sub>2</sub> is an effective dopant, addressing key limitations such as hard sintering, inadequate thermal shock resistance, and insufficient chemical stability. Firstly, the strong sintering ability of TiO<sub>2</sub> promoted the densification of MgO crucibles by generating a liquid phase composed of TiO<sub>2</sub>–MgO–CaO–SiO<sub>2</sub>, resulting in a significant reduction in open porosity from 12.62% to 9.76% at a doping level of 5 wt%. Moreover, TiO<sub>2</sub> alters the initial bonding phase from Ca<sub>2</sub>SiO<sub>4</sub> into CaTiO<sub>3</sub>, Mg<sub>2</sub>SiO<sub>4</sub>, and Mg<sub>2</sub>TiO<sub>4</sub>, enhancing thermal shock resistance by generating microcracks, lowering thermal expansion coefficient, and detaching the matrix/aggregate bonding. Notably, adding TiO<sub>2</sub> enhanced the corrosion resistance of MgO ceramic crucibles, reducing the total impurity content in the alloy from 0.0021 wt% to 0.0007 wt%. In summary, TiO<sub>2</sub>-doped MgO crucibles demonstrated superior performance compared to pure MgO and MgAl<sub>2</sub>O<sub>4</sub> crucibles.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 402-415"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.017
Wenhong Peng , Yichen Wu , Ruming Geng , Yuxian Cao , Shun Han , Yong Li , Chunxu Wang , Lijing Zheng
The development of ultra-high strength steels with balanced ductility and toughness is of significant industrial importance. In the present study, impact toughness, tensile properties, and microstructural evolution of high-Co-Ni secondary hardening steels were investigated by adding Ni from 13 to 15 wt%. Within a certain range, Ni effectively refines the grain size and the thickness of austenite films, facilitating the enrichment of Ni in nanoscale film reverted austenite, thereby enhancing the austenite stability and toughness in steels.At a Ni concentration of 14 wt%, the steel exhibits the most refined martensitic substructure and nanoscale film-like reverted austenite, enriched with Ni, along with the precipitation of a significant volume of nanoscale semi-coherent (Mo,Cr)2C phases. This microstructural configuration yields an optimal synergy of strength and toughness, with an ultimate tensile strength reaching approximately 2.3 GPa and a Charpy impact energy of around 34 J. However, an increment in Ni content results in a higher volume fraction of Ni-enriched reverted austenite, which poses challenges to eliminate during low-temperature and aging processes, consequently reducing the steel's toughness. This comprehensive study provides a foundation for the design of ultra-high-strength alloys with tailored strength and toughness, highlighting the pivotal role of Ni in achieving this balance.
{"title":"Microstructures and mechanical properties of novel 2.3 GPa secondary hardening steels with different Ni contents","authors":"Wenhong Peng , Yichen Wu , Ruming Geng , Yuxian Cao , Shun Han , Yong Li , Chunxu Wang , Lijing Zheng","doi":"10.1016/j.jmrt.2025.01.017","DOIUrl":"10.1016/j.jmrt.2025.01.017","url":null,"abstract":"<div><div>The development of ultra-high strength steels with balanced ductility and toughness is of significant industrial importance. In the present study, impact toughness, tensile properties, and microstructural evolution of high-Co-Ni secondary hardening steels were investigated by adding Ni from 13 to 15 wt%. Within a certain range, Ni effectively refines the grain size and the thickness of austenite films, facilitating the enrichment of Ni in nanoscale film reverted austenite, thereby enhancing the austenite stability and toughness in steels.At a Ni concentration of 14 wt%, the steel exhibits the most refined martensitic substructure and nanoscale film-like reverted austenite, enriched with Ni, along with the precipitation of a significant volume of nanoscale semi-coherent (Mo,Cr)<sub>2</sub>C phases. This microstructural configuration yields an optimal synergy of strength and toughness, with an ultimate tensile strength reaching approximately 2.3 GPa and a Charpy impact energy of around 34 J. However, an increment in Ni content results in a higher volume fraction of Ni-enriched reverted austenite, which poses challenges to eliminate during low-temperature and aging processes, consequently reducing the steel's toughness. This comprehensive study provides a foundation for the design of ultra-high-strength alloys with tailored strength and toughness, highlighting the pivotal role of Ni in achieving this balance.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 675-684"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.015
Gang Du , Canhua Li , Jiamao Li , Guangchao Wu , Zhenyi Huang , Aiqin Mao , Mengchen Ma , Zhiyun Guo , Zhao Chen
High entropy oxide ceramics impart diverse excellent characteristics and extensive application potential to the high entropy oxide family, owing to their distinct high entropy effects and lattice distortions. Starting from the basic definition of entropy, this article provided a detailed introduction to the design principles of high entropy oxide ceramics. It summarizes five main crystal types: rock salt type, fluorite type, perovskite type, spinel type, and pyrochlore type. The three main preparation processes of solid-phase method, liquid-phase method, and gas-phase method are summarized, and the performance and applications of high entropy oxide ceramics in the fields of thermodynamics, mechanics, catalysis, and electromagnetic energy storage are deeply explored. Finally, this article provides an outlook on the development direction and future trends of high entropy oxide ceramics, providing inspiration and reference for further research in this field.
{"title":"Research progress on high entropy oxide ceramics: Principles, preparation, and properties","authors":"Gang Du , Canhua Li , Jiamao Li , Guangchao Wu , Zhenyi Huang , Aiqin Mao , Mengchen Ma , Zhiyun Guo , Zhao Chen","doi":"10.1016/j.jmrt.2025.01.015","DOIUrl":"10.1016/j.jmrt.2025.01.015","url":null,"abstract":"<div><div>High entropy oxide ceramics impart diverse excellent characteristics and extensive application potential to the high entropy oxide family, owing to their distinct high entropy effects and lattice distortions. Starting from the basic definition of entropy, this article provided a detailed introduction to the design principles of high entropy oxide ceramics. It summarizes five main crystal types: rock salt type, fluorite type, perovskite type, spinel type, and pyrochlore type. The three main preparation processes of solid-phase method, liquid-phase method, and gas-phase method are summarized, and the performance and applications of high entropy oxide ceramics in the fields of thermodynamics, mechanics, catalysis, and electromagnetic energy storage are deeply explored. Finally, this article provides an outlook on the development direction and future trends of high entropy oxide ceramics, providing inspiration and reference for further research in this field.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 265-288"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.044
Zhen Guo , Hui Ma , Danmin Peng , Hongwei Bao , Zhipeng Sun , Yong Xin , Jibin Zhang , Fei Ma
The interaction between fission gas Xe and grain boundaries (GBs) in polycrystalline UO2 nuclear fuel is intricate at elevated temperatures. Herein, molecular dynamics simulations were employed to investigate the structural characteristics and evolution of intergranular and intragranular Xe bubbles in UO2. The results indicate that temperature elevating will significantly disorder the atomic structure and geometry of Xe bubbles, as a result, the pressure of Xe bubbles is lowered with expanded volume. Especially, the intergranular Xe bubbles are more sensitive to temperature and, generally, they suffer the higher pressure with the smaller volume, as compared to those of the intragranular Xe bubbles. The higher the temperature, the faster the migration of GBs. Consequently, at the lower temperature, GBs migrate at a lower migration rate, so that Xe atoms have enough time to diffuse into GBs when Xe bubbles meet GBs, while only part of Xe atoms are diffused into GBs at the higher temperature, and the residual Xe atoms are left behind GBs, with the bubble morphology changing from cluster-shaped into short-rod like. The elevated temperature and the Xe atoms diffused into GBs could promote the migration of GBs. However, the residual Xe bubble hinders the migration of GBs. Interestingly, reordering of the disrupted atomic structure occurs in Σ5b STGB, which might alter the shear-coupling factor β value from negative to positive, leading to an opposite migration of GBs at 1200 K or higher. The results are of significant guidance to understanding on Xe bubble structure and GB migration.
{"title":"Temperature effects on Xe bubble structure and grain boundary migration in UO2: A molecular dynamics simulation","authors":"Zhen Guo , Hui Ma , Danmin Peng , Hongwei Bao , Zhipeng Sun , Yong Xin , Jibin Zhang , Fei Ma","doi":"10.1016/j.jmrt.2025.01.044","DOIUrl":"10.1016/j.jmrt.2025.01.044","url":null,"abstract":"<div><div>The interaction between fission gas Xe and grain boundaries (GBs) in polycrystalline UO<sub>2</sub> nuclear fuel is intricate at elevated temperatures. Herein, molecular dynamics simulations were employed to investigate the structural characteristics and evolution of intergranular and intragranular Xe bubbles in UO<sub>2</sub>. The results indicate that temperature elevating will significantly disorder the atomic structure and geometry of Xe bubbles, as a result, the pressure of Xe bubbles is lowered with expanded volume. Especially, the intergranular Xe bubbles are more sensitive to temperature and, generally, they suffer the higher pressure with the smaller volume, as compared to those of the intragranular Xe bubbles. The higher the temperature, the faster the migration of GBs. Consequently, at the lower temperature, GBs migrate at a lower migration rate, so that Xe atoms have enough time to diffuse into GBs when Xe bubbles meet GBs, while only part of Xe atoms are diffused into GBs at the higher temperature, and the residual Xe atoms are left behind GBs, with the bubble morphology changing from cluster-shaped into short-rod like. The elevated temperature and the Xe atoms diffused into GBs could promote the migration of GBs. However, the residual Xe bubble hinders the migration of GBs. Interestingly, reordering of the disrupted atomic structure occurs in Σ5b STGB, which might alter the shear-coupling factor β value from negative to positive, leading to an opposite migration of GBs at 1200 K or higher. The results are of significant guidance to understanding on Xe bubble structure and GB migration.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 743-753"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.042
Bingtian Li , Zhenjie Guan , AnRan Li , Ziyao Chen , Weijian Li , Liang Zhen , Wenzhu Shao
The preferential oxidation of alloying elements has long been recognized as the primary mechanism underlying the oxidation resistance of copper alloys. However, the presence of various alloy phases within the Cu matrix complicates the oxidation behavior. Herein, combined DFT calculations and antioxidation experiment were conducted to evaluate the oxidation behavior and underlying mechanism of Cu–La alloys. The results indicate that the oxidation resistance of Cu is significantly enhanced by La element with a reduced mass gain of 49% at 100 °C for 100 h. The effects of oxidation behavior of Cu6La on the oxidation resistance of Cu is further explored by DFT calculations. It reveals that the Cu6La phase with a low work function exhibits a strong affinity for the O atoms. However, the diffusion activation energy of the absorbed O is calculated to be lower in Cu6La than that of O in Cu, which is conducive to mitigate the further erosion of O on Cu matrix. Moreover, the Cu2O–La layer formed on the Cu6La surface is more stable and the oxygen diffusion coefficient in it is lower, which impedes the entry of oxygen. This work advances the understanding of alloying effect on oxidation of Cu surfaces that can be extended to other metal surfaces.
{"title":"Unveiling the influence mechanism of La alloy on the oxidation behavior of Cu contact materials: A combined experimental and density functional investigation","authors":"Bingtian Li , Zhenjie Guan , AnRan Li , Ziyao Chen , Weijian Li , Liang Zhen , Wenzhu Shao","doi":"10.1016/j.jmrt.2025.01.042","DOIUrl":"10.1016/j.jmrt.2025.01.042","url":null,"abstract":"<div><div>The preferential oxidation of alloying elements has long been recognized as the primary mechanism underlying the oxidation resistance of copper alloys. However, the presence of various alloy phases within the Cu matrix complicates the oxidation behavior. Herein, combined DFT calculations and antioxidation experiment were conducted to evaluate the oxidation behavior and underlying mechanism of Cu–La alloys. The results indicate that the oxidation resistance of Cu is significantly enhanced by La element with a reduced mass gain of 49% at 100 °C for 100 h. The effects of oxidation behavior of Cu<sub>6</sub>La on the oxidation resistance of Cu is further explored by DFT calculations. It reveals that the Cu<sub>6</sub>La phase with a low work function exhibits a strong affinity for the O atoms. However, the diffusion activation energy of the absorbed O is calculated to be lower in Cu<sub>6</sub>La than that of O in Cu, which is conducive to mitigate the further erosion of O on Cu matrix. Moreover, the Cu<sub>2</sub>O–La layer formed on the Cu<sub>6</sub>La surface is more stable and the oxygen diffusion coefficient in it is lower, which impedes the entry of oxygen. This work advances the understanding of alloying effect on oxidation of Cu surfaces that can be extended to other metal surfaces.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 481-490"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.035
Yulun Luo , Zhihua Dong , Bin Jiang , Zhiying Zheng , Jianxin Zhou , Yongfeng Li , Shengwen Bai , Shiyu Zhong , Jiangfeng Song , Dingfei Zhang
The influence of heat treatment prior to hot extrusion on microstructure evolution and mechanical properties are elaborated for Mg–7Y–2Zn–1Mn (wt. %) alloy containing long-period stacking ordered (LPSO) phase. Solution and aging treatment are shown to increase obviously tensile strength of the alloy, while keeping relatively high ductility. Good comprehensive mechanical properties with the ultimate tensile strength of 396 MPa, yield strength of 314 MPa, and elongation of 9.7 % are achieved by the aging treatment. It is closely correlated with the formation bimodal structure and the enhanced precipitation of γ′ and lamellar 14H-LPSO phase. While the granular 18R-LPSO phase and the kink deformation of lamellar 14H-LPSO phase are found to promote the dynamic recrystallization process during hot extrusion, the formation of large amount of γ′ and lamellar 14H-LPSO phase tends to uniform the stress and hinder the dynamic recrystallization process. Balance of the two factors contributes to the formation of bimodal structure and the improved mechanical properties. The present advances enhance the understanding required for the optimal design of thermo-mechanical process of LPSO-containing Mg alloys.
{"title":"Achieving good comprehensive mechanical properties Mg–7Y–2Zn–1Mn alloy via regulating heat treatment prior to hot extrusion","authors":"Yulun Luo , Zhihua Dong , Bin Jiang , Zhiying Zheng , Jianxin Zhou , Yongfeng Li , Shengwen Bai , Shiyu Zhong , Jiangfeng Song , Dingfei Zhang","doi":"10.1016/j.jmrt.2025.01.035","DOIUrl":"10.1016/j.jmrt.2025.01.035","url":null,"abstract":"<div><div>The influence of heat treatment prior to hot extrusion on microstructure evolution and mechanical properties are elaborated for Mg–7Y–2Zn–1Mn (wt. %) alloy containing long-period stacking ordered (LPSO) phase. Solution and aging treatment are shown to increase obviously tensile strength of the alloy, while keeping relatively high ductility. Good comprehensive mechanical properties with the ultimate tensile strength of 396 MPa, yield strength of 314 MPa, and elongation of 9.7 % are achieved by the aging treatment. It is closely correlated with the formation bimodal structure and the enhanced precipitation of γ′ and lamellar 14H-LPSO phase. While the granular 18R-LPSO phase and the kink deformation of lamellar 14H-LPSO phase are found to promote the dynamic recrystallization process during hot extrusion, the formation of large amount of γ′ and lamellar 14H-LPSO phase tends to uniform the stress and hinder the dynamic recrystallization process. Balance of the two factors contributes to the formation of bimodal structure and the improved mechanical properties. The present advances enhance the understanding required for the optimal design of thermo-mechanical process of LPSO-containing Mg alloys.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 332-343"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.043
Quan Shao , Emad M. Elgallad , Alexandre Maltais , X.-Grant Chen
Four Al–Zr-Sc conductor alloys with 0.1–0.18 wt% Zr and 0.1–0.15 wt% Sc were processed through casting, hot rolling, heat treatments, and cold wire drawing. The mechanical properties and electrical conductivities of the alloy wires were evaluated, and the microstructures were characterized using scanning electron microscopy, transmission electron microscopy, and electron backscattering diffraction techniques. The thermal stabilities of these alloys were systematically assessed during thermal exposures at 310, 350, and 400 °C for up to 1000 h. The ultimate tensile strengths (UTSs) of four Al–Zr-Sc alloy wires reached 206–214 MPa, while the electrical conductivities were 57%–57.5% IACS. All four alloy wires were strengthened by a large number of Al3(Sc,Zr) nanoprecipitates. With the increase in Zr or Sc content, the UTS only slightly increased, which shows a low impact of the Zr and Sc levels on the tensile strength and electrical conductivity. Notably, remarkable reduction in tensile strength and change in the deformed grain structure were not observed for the four alloy wires during thermal exposure at 310 °C for up to 1000 h. After thermal exposure at 350 °C for 200 h, all four wires still exhibited excellent thermal stabilities. With prolonged exposures at 350 and 400 °C, the alloy wires became unstable. The high-Zr-content Al-0.18Zr-0.1Sc and Al-0.18Zr-0.15Sc alloys exhibited better thermal stabilities after long-term thermal exposures at 350 and 400 °C. This study on the thermal stability of Al–Zr-Sc conductor alloys under extreme conditions provides a valuable reference for industrial applications of thermally resistant Al conductor wires.
{"title":"Thermal stability of Al–Zr-Sc conductor alloys during long-term elevated-temperature exposures","authors":"Quan Shao , Emad M. Elgallad , Alexandre Maltais , X.-Grant Chen","doi":"10.1016/j.jmrt.2025.01.043","DOIUrl":"10.1016/j.jmrt.2025.01.043","url":null,"abstract":"<div><div>Four Al–Zr-Sc conductor alloys with 0.1–0.18 wt% Zr and 0.1–0.15 wt% Sc were processed through casting, hot rolling, heat treatments, and cold wire drawing. The mechanical properties and electrical conductivities of the alloy wires were evaluated, and the microstructures were characterized using scanning electron microscopy, transmission electron microscopy, and electron backscattering diffraction techniques. The thermal stabilities of these alloys were systematically assessed during thermal exposures at 310, 350, and 400 °C for up to 1000 h. The ultimate tensile strengths (UTSs) of four Al–Zr-Sc alloy wires reached 206–214 MPa, while the electrical conductivities were 57%–57.5% IACS. All four alloy wires were strengthened by a large number of Al<sub>3</sub>(Sc,Zr) nanoprecipitates. With the increase in Zr or Sc content, the UTS only slightly increased, which shows a low impact of the Zr and Sc levels on the tensile strength and electrical conductivity. Notably, remarkable reduction in tensile strength and change in the deformed grain structure were not observed for the four alloy wires during thermal exposure at 310 °C for up to 1000 h. After thermal exposure at 350 °C for 200 h, all four wires still exhibited excellent thermal stabilities. With prolonged exposures at 350 and 400 °C, the alloy wires became unstable. The high-Zr-content Al-0.18Zr-0.1Sc and Al-0.18Zr-0.15Sc alloys exhibited better thermal stabilities after long-term thermal exposures at 350 and 400 °C. This study on the thermal stability of Al–Zr-Sc conductor alloys under extreme conditions provides a valuable reference for industrial applications of thermally resistant Al conductor wires.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 164-175"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-07DOI: 10.1016/j.jmrt.2025.01.032
Shaoning Geng, Yuantai Li, Ping Jiang, Yilin Wang, Jun Jin, Chu Han
This paper aims to investigate the influence of welding sequences on welding induced residual stress and deformation of U-rib components fabricated by laser-arc hybrid welding through experimental and numerical methods. A thermo-elastic-plastic finite element model was developed to capture the complex thermal and mechanical behavior during the U-rib welding process. The model was validated by neutron diffraction testing of residual stress in U-rib joints focusing on a typical continuous sequential welding condition. To further quantify the residual stress and residual deformation induced by different welding sequences, eight models of continuous and segmental welding sequences are conducted. The results show that the experimental and numerical results are in general agreement in terms of temperature field, melt pool morphology, residual stress, and deformation. The neutron diffraction validation shows an S-shaped curve along the potential crack propagation path in the joint and emphasizes the reliability of the model. Welding sequence has effect on the longitudinal stress in the weld and deck top of the U-rib joints but little influence on the transverse residual stress. The continuous welding sequence shows a bimodal pattern with almost identical peaks for both welds, while the segmental welding sequences clearly exhibit one peak high and one peak low. Segmental double-sided simultaneous welding with the “End→Middle←End” path significantly reduces residual deformation, decreasing the maximum bending deformation by approximately 33% compared to continuous sequential welding. This study provides theoretical and technical guidance for improving high quality fabrication of U-rib components and large welded structures using laser-arc hybrid welding.
{"title":"Influence of welding sequences on residual stress and deformation of U-rib components fabricated by laser-arc hybrid welding","authors":"Shaoning Geng, Yuantai Li, Ping Jiang, Yilin Wang, Jun Jin, Chu Han","doi":"10.1016/j.jmrt.2025.01.032","DOIUrl":"10.1016/j.jmrt.2025.01.032","url":null,"abstract":"<div><div>This paper aims to investigate the influence of welding sequences on welding induced residual stress and deformation of U-rib components fabricated by laser-arc hybrid welding through experimental and numerical methods. A thermo-elastic-plastic finite element model was developed to capture the complex thermal and mechanical behavior during the U-rib welding process. The model was validated by neutron diffraction testing of residual stress in U-rib joints focusing on a typical continuous sequential welding condition. To further quantify the residual stress and residual deformation induced by different welding sequences, eight models of continuous and segmental welding sequences are conducted. The results show that the experimental and numerical results are in general agreement in terms of temperature field, melt pool morphology, residual stress, and deformation. The neutron diffraction validation shows an S-shaped curve along the potential crack propagation path in the joint and emphasizes the reliability of the model. Welding sequence has effect on the longitudinal stress in the weld and deck top of the U-rib joints but little influence on the transverse residual stress. The continuous welding sequence shows a bimodal pattern with almost identical peaks for both welds, while the segmental welding sequences clearly exhibit one peak high and one peak low. Segmental double-sided simultaneous welding with the “End→Middle←End” path significantly reduces residual deformation, decreasing the maximum bending deformation by approximately 33% compared to continuous sequential welding. This study provides theoretical and technical guidance for improving high quality fabrication of U-rib components and large welded structures using laser-arc hybrid welding.</div></div>","PeriodicalId":54332,"journal":{"name":"Journal of Materials Research and Technology-Jmr&t","volume":"35 ","pages":"Pages 726-742"},"PeriodicalIF":6.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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