首次利用CiteSpace文献计量分析软件对Web of Science中2003—2023年高温结构材料用Laves相研究文献的关键词、文献共被引、作者和期刊共被引进行了定量和可视化网络图谱分析。关键词聚类时间线图反映了检索区间内Laves相研究的基本发...首次利用CiteSpace文献计量分析软件对Web of Science中2003—2023年高温结构材料用Laves相研究文献的关键词、文献共被引、作者和期刊共被引进行了定量和可视化网络图谱分析。关键词聚类时间线图反映了检索区间内Laves相研究的基本发展状况,揭示两大热点前沿主题分别是Laves相增强的多相高熵合金的室温脆性改善或强度-塑性协同提升问题,以及Laves相析出物对600~650℃蠕变服役条件下P92、12Cr和G115等新型耐热合金钢组织与性能的影响。关键词聚类时间线图与文献、作者共被引网络图具备一致性,共同反映Laves相研究的活跃性。未来,应关注可视化图谱挖掘的高质量成果产出的关键作者和期刊。展开更多
The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 9...The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.展开更多
The effects of the Laves-decorated dendrite structure on the hydrogen-assisted cracking behavior of the SLM-718 alloy were investigated.The Laves phase exhibits a hydrogen desorption activation energy of 47.67±7....The effects of the Laves-decorated dendrite structure on the hydrogen-assisted cracking behavior of the SLM-718 alloy were investigated.The Laves phase exhibits a hydrogen desorption activation energy of 47.67±7.85 kJ mol^(-1).The results of in situ scanning Kelvin probe force microscopy and hydrogen microprint technique provide direct evidence of the hydrogen trapping by the Laves phase.The high-density dendrite walls consisting of entangled dislocations exhibit an inhibitory effect on hydrogen diffusion.Atomic-scale characterization reveals that dislocation stacking at the Laves/γ-matrix interface induces the formation of dislocation defects and a high-stress concentration in the Laves phase.The presence of hydrogen further promotes the formation of micropore defects and the embrittlement of the Laves phase.Hydrogen-promoted dislocation slip localization and hydrogen-induced reduction of interatomic bonding are the primary reasons for the Laves phase fracture and debonding at the Laves/γ-matrix interface.The coalescence of micropore defects ultimately leads to hydrogen-induced crack formation.展开更多
The mechanical properties of Mg–Al–Ca alloys are significantly affected by their Laves phases,including the Al_(2)Ca phase.Laves phases are generally considered to be brittle and have a detrimental effect on the duc...The mechanical properties of Mg–Al–Ca alloys are significantly affected by their Laves phases,including the Al_(2)Ca phase.Laves phases are generally considered to be brittle and have a detrimental effect on the ductility of Mg.Recently,the Al_(2)Ca phase was shown to undergo plastic deformation in a dilute Mg-Al-Ca alloy to increase the ductility and work hardening of the alloy.In the present study,we investigated the extent to which the deformation of Al_(2)Ca is driven by dislocations in the Mg matrix by simulating the interactions between the basal edge dislocations and Al_(2)Ca particles.In particular,the effects of the interparticle spacing,particle orientation,and particle size were considered.Shearing of small particles and dislocation cross-slips near large particles were observed.Both events contribute to strengthening,and accommodate to plasticity.The shear resistance of the dislocation to bypass the particles increased as the particle size increased.The critical resolved shear stress(CRSS)for activating dislocations and stacking faults was easier to reach for small Al_(2)Ca particles owing to the higher local shear stress,which is consistent with the experimental observations.Overall,this work elucidates the driving force for Al_(2)Ca particles in Mg–Al–Ca alloys to undergo plastic deformation.展开更多
文摘首次利用CiteSpace文献计量分析软件对Web of Science中2003—2023年高温结构材料用Laves相研究文献的关键词、文献共被引、作者和期刊共被引进行了定量和可视化网络图谱分析。关键词聚类时间线图反映了检索区间内Laves相研究的基本发展状况,揭示两大热点前沿主题分别是Laves相增强的多相高熵合金的室温脆性改善或强度-塑性协同提升问题,以及Laves相析出物对600~650℃蠕变服役条件下P92、12Cr和G115等新型耐热合金钢组织与性能的影响。关键词聚类时间线图与文献、作者共被引网络图具备一致性,共同反映Laves相研究的活跃性。未来,应关注可视化图谱挖掘的高质量成果产出的关键作者和期刊。
文摘The precipitation of secondary Laves phases and its effect on notch sensitivity are systematically studied in Thermo-Span alloy. The results show that the precipitation peak temperature of secondary Laves phases is 925 ℃. Below 925 ℃, the volume fraction of secondary Laves phases increases with the rise of the temperature, and its morphology changes from granular to thin-film;above 925 ℃, the volume fraction of secondary Laves phases shows an opposite trend to temperature, and its morphology changes from thin-film to granular. A detailed explanation through linear density (ρ) is provided that the influence of secondary Laves phases at the grain boundaries (GBs) on notch sensitivity depends on the coupling competition effect of their size, quantity, and morphology. Notably, the granular Laves phases are more beneficial to improving the notch sensitivity of the alloy compared with thin-film Laves phases. Granular secondary Laves phases can promote the formation of γ′ phases depletion zone to improve the ability of GBs to accommodate high strain localization, and effectively inhibit the crack initiation and propagation.
基金financially supported by the National Natural Science Foundation of China(Nos.U21A2044 and 52201060)CGN-USTB Joint Research and Development Center for Advanced Energy Materials and Service Safet.
文摘The effects of the Laves-decorated dendrite structure on the hydrogen-assisted cracking behavior of the SLM-718 alloy were investigated.The Laves phase exhibits a hydrogen desorption activation energy of 47.67±7.85 kJ mol^(-1).The results of in situ scanning Kelvin probe force microscopy and hydrogen microprint technique provide direct evidence of the hydrogen trapping by the Laves phase.The high-density dendrite walls consisting of entangled dislocations exhibit an inhibitory effect on hydrogen diffusion.Atomic-scale characterization reveals that dislocation stacking at the Laves/γ-matrix interface induces the formation of dislocation defects and a high-stress concentration in the Laves phase.The presence of hydrogen further promotes the formation of micropore defects and the embrittlement of the Laves phase.Hydrogen-promoted dislocation slip localization and hydrogen-induced reduction of interatomic bonding are the primary reasons for the Laves phase fracture and debonding at the Laves/γ-matrix interface.The coalescence of micropore defects ultimately leads to hydrogen-induced crack formation.
基金funded by the National Natural Science Foundation of China(nos.51631006 and 51825101)。
文摘The mechanical properties of Mg–Al–Ca alloys are significantly affected by their Laves phases,including the Al_(2)Ca phase.Laves phases are generally considered to be brittle and have a detrimental effect on the ductility of Mg.Recently,the Al_(2)Ca phase was shown to undergo plastic deformation in a dilute Mg-Al-Ca alloy to increase the ductility and work hardening of the alloy.In the present study,we investigated the extent to which the deformation of Al_(2)Ca is driven by dislocations in the Mg matrix by simulating the interactions between the basal edge dislocations and Al_(2)Ca particles.In particular,the effects of the interparticle spacing,particle orientation,and particle size were considered.Shearing of small particles and dislocation cross-slips near large particles were observed.Both events contribute to strengthening,and accommodate to plasticity.The shear resistance of the dislocation to bypass the particles increased as the particle size increased.The critical resolved shear stress(CRSS)for activating dislocations and stacking faults was easier to reach for small Al_(2)Ca particles owing to the higher local shear stress,which is consistent with the experimental observations.Overall,this work elucidates the driving force for Al_(2)Ca particles in Mg–Al–Ca alloys to undergo plastic deformation.
