The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural ...The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.展开更多
Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-stat...Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-state lithium batteries(ASSLBs)compared to the overly reactive metallic lithium anode and the mechanically weak silicon anode.This study finds that the pre-lithiated Al anode demonstrates outstanding interfacial stability with the Li_6PS_5Cl(LPSCl)electrolyte,maintaining stable cycling for over 1200 h under conditions of deep charge-discharge.This paper combines the pre-lithiated Al anode with a high-nickel cathode,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),paired with the highly ionic conductive LPSCl electrolyte,to design an ASSLB with high energy density and stability.Using anode pre-lithiation techniques,along with dual-reinforcement technology between the electrolyte and the cathode active material,the ASSLB achieves stable cycling for 1000 cycles at a 0.2C rate,with a capacity retention rate of up to 82.2%.At a critical negative-to-positive ratio of 1.1,the battery's specific energy reaches up to 375 Wh kg^(-1),and it maintains over 85.9%of its capacity after 100 charge-discharge cycles.This work provides a new approach and an excellent solution for developing low-cost,high-stability all-solid-state batteries.展开更多
A combination of casting and laser remelting was employed to develop a high-strength and heat-resistant Al-Si-Fe alloy suitable for powder bed fusion using a laser beam(PBF-LB).By clarifying the effects of the incorpo...A combination of casting and laser remelting was employed to develop a high-strength and heat-resistant Al-Si-Fe alloy suitable for powder bed fusion using a laser beam(PBF-LB).By clarifying the effects of the incorporated elements and their contents on the microstructure and mechanical performance of Al-Si-Fe alloys,the composition was optimized as Al-11Si-2.5Fe-2Mn-1.2Ni-0.4Cr(in wt.%).The optimized alloy was subsequently validated using PBF-LB,which exhibited favorable machinability,achieving a density of 99.8%.The room-temperature tensile strength of the PBF-LB manufactured Al-Si-Fe alloy reached(512.76±3.26)MPa,with a yield strength of(337.79±2.36)MPa and an elongation of(2.98±0.07)%.The enhanced room-temperature mechanical properties could be mainly attributed to the combined effects of fine-grain strengthening,solid solution strengthening,and precipitation strengthening.At 300°C,the high-temperature tensile strength of the developed alloy reached(222.47±6.41)MPa,with a yield strength of(164.25±11.40)MPa and an elongation of(8.88±0.33)%,outperforming those of existing alloys documented in the literature.The improved high-temperature mechanical performance was primarily provided by the three-dimensional network comprising cellular heat-resistant Al17(FeMnNiCr)4Si2 andα-Al(FeMn)Si phases.展开更多
A Ti(Al,Si)3 diffusion coating was prepared on γ-TiAl alloy by cold sprayed Al?20Si alloy coating, followed by a heat-treatment. The isothermal and cyclic oxidation tests were conducted at 900 °C for 1000 h and ...A Ti(Al,Si)3 diffusion coating was prepared on γ-TiAl alloy by cold sprayed Al?20Si alloy coating, followed by a heat-treatment. The isothermal and cyclic oxidation tests were conducted at 900 °C for 1000 h and 120 cycles to check the oxidation resistance of the coating. The microstructure and phase transformation of the coating before and after the oxidation were studied by SEM, XRD and EPMA. The results indicate that the diffusion coating shows good oxidation resistance. The mass gain of the diffusion coating is only a quarter of that of bare alloy. After oxidation, the diffusion coating is degraded into three layers: an inner TiAl2 layer, a two-phase intermediate layer composed of a Ti(Al,Si)3 matrix and Si-rich precipitates, and a porous layer because of the inter-diffusion between the coating and substrate.展开更多
The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the...The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the coating oxidized in ambient air at 1000 °C for 25-250 h were investigated using SEM, X-ray diffraction and optical microscope methods. The results show that the copper with single phase Ni2Al3 coating possesses the best high temperature oxidation resistance, and the mass gain of the coating is 1/15 that of pure copper and 1/2 that of nickel coating, respectively. The specimen surface after being oxidized for 25 h still comprises Ni2Al3 phase. However, when the time of oxidizing treatment increases to 50 h, the Ni Al phase is formed. It is also found that the Ni2Al3 phase completely turns into Ni Al phase after oxidizing treatment for 100 h and above. The Ni Al coating shows excellent high temperature oxidation resistance when oxidation time is 250 h.展开更多
Fluoride mediated nano-sized ZSM-5 （ZSM-5-F） with a high Si/AI ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene （MTP） reaction. High propylene sele...Fluoride mediated nano-sized ZSM-5 （ZSM-5-F） with a high Si/AI ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene （MTP） reaction. High propylene selectivity （45%） was similar to ZSM-5-OH synthesized via a hydroxide route. However, ZSM- 5-F showed much longer lifetime （305 h） compared with ZSM-5-OH （157 h） in spite of similar crystal size and aluminum content. Characterization by NH3-TPD. Py-IR, OH-IR, SEM, TG-DTA, XRD and 1H MAS NMR techniques indicated that the enhanced catalytic performance of ZSM-S-F is attributed to the fewer structural defects in the form of internal silanol groups and silanol nests.展开更多
To explore the effect of strain rate ε on the high temperature deformation characteristics of ultrafine-grained materials, the deformation and damage features as well as microstructures of ECAP-treated pure Al at dif...To explore the effect of strain rate ε on the high temperature deformation characteristics of ultrafine-grained materials, the deformation and damage features as well as microstructures of ECAP-treated pure Al at different temperatures T and strain ratesε were systematically studied through compression tests and microscopic observations. The increase in ε eliminates strain softening at T≤473 K, and largely enhances the yield strength and flow stress at 473?573 K. The shear deformation dominates the plastic deformation of ECAP-treated Al. Many cracks along shear bands (SBs) are formed at T≥473 K and secondary SBs basically disappear at 1×10?3 s?1; however, at 1×10?2 s?1, cracks are only observed at temperature below 473 K, and secondary SBs become clearer at T≥473 K. The microstructures of ECAP-treated Al mainly consist of sub-grains (SGs). The increase in ε inhibits the SG growth, thus leading to the increases both in yield strength and flow stress at high temperatures.展开更多
The influences of high temperature pre-straining (HT-PS) on the natural aging and bake hardening of Al?Mg?Si alloys were investigated by Vickers microhardness measurements, differential scanning calorimetry (DSC) anal...The influences of high temperature pre-straining (HT-PS) on the natural aging and bake hardening of Al?Mg?Si alloys were investigated by Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterization. The results show that pre-straining at 170 °C immediately after quenching can effectively resolve the rather high T4 temper hardness caused by the conventional room temperature (RT) pre-straining treatment, and give a better bake hardening response (BHR) after paint-bake cycle. HT-PS 7% at 170 °C for 10 min is chosen as the optimum process as it provides lower T4 temper hardness and better BHR. The simultaneous introduction of dislocations and Cluster (2) can significantly suppress the natural aging and promote the precipitation of β″ phase, and reduce the effects of deformation hardening by dynamic recovery.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 52075449, 51975480)。
文摘The dissimilar 2B06 and 7B04 Al alloy joints were prepared by refill friction stir spot welding(RFSSW),and the microstructural evolution and corrosion behavior of the joints were investigated.Based on microstructural analysis,the welded joints exhibit distinct microstructural zones,including the stir zone(SZ),thermomechanically affected zone(TMAZ),and heat-affected zone(HAZ).The grain size of each zone is in the order of HAZ>TMAZ>SZ.Notably,the TMAZ and HAZ contain significantly larger secondary-phase particles compared to the SZ,with particle size in the HAZ increasing at higher rotational speeds.Electrochemical tests indicate that corrosion susceptibility follows the sequence of HAZ>TMAZ>SZ>BM,with greater sensitivity observed at increased rotational speeds.Post-corrosion mechanical performance degradation primarily arises from crevice corrosion at joint overlaps,but not from the changes in the microstructure.
基金the technical support for Nano-X from Suzhou Institute of Nano-Tech and NanoBionics,Chinese Academy of Sciences(SINANO)supported by the National Key R&D Program of China(2021YFB3800300)+2 种基金the National Natural Science Foundation of China(22179059,22239002,92372201)the science and technology innovation fund for emission peak and carbon neutrality of Jiangsu province(BK20231512,BK20220034)the Key R&D project funded by department of science and technology of Jiangsu Province(BE2020003)。
文摘Aluminum(Al)exhibits excellent electrical conductivity,mechanical ductility,and good chemical compatibility with high-ionic-conductivity electrolytes.This makes it more suitable as an anode material for all-solid-state lithium batteries(ASSLBs)compared to the overly reactive metallic lithium anode and the mechanically weak silicon anode.This study finds that the pre-lithiated Al anode demonstrates outstanding interfacial stability with the Li_6PS_5Cl(LPSCl)electrolyte,maintaining stable cycling for over 1200 h under conditions of deep charge-discharge.This paper combines the pre-lithiated Al anode with a high-nickel cathode,LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),paired with the highly ionic conductive LPSCl electrolyte,to design an ASSLB with high energy density and stability.Using anode pre-lithiation techniques,along with dual-reinforcement technology between the electrolyte and the cathode active material,the ASSLB achieves stable cycling for 1000 cycles at a 0.2C rate,with a capacity retention rate of up to 82.2%.At a critical negative-to-positive ratio of 1.1,the battery's specific energy reaches up to 375 Wh kg^(-1),and it maintains over 85.9%of its capacity after 100 charge-discharge cycles.This work provides a new approach and an excellent solution for developing low-cost,high-stability all-solid-state batteries.
基金supported by the National Natural Science Foundation of China(Nos.52375393,52071299)the Science and Technology Innovation Talent Team of Shanxi Province,China(No.202304051001029)+3 种基金the Scientific and Technological Achievements Transformation Guidance Project of Shanxi Province,China(No.202204021301048)the Key R&D Program of Shanxi Province,China(Nos.2210300058MZ,202202150401020)the Hai’an&Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute,China(No.2023HA-TYUTKFYF020)the Young Elite Scientists Sponsorship Program by CAST,China(No.2023QNRC001).
文摘A combination of casting and laser remelting was employed to develop a high-strength and heat-resistant Al-Si-Fe alloy suitable for powder bed fusion using a laser beam(PBF-LB).By clarifying the effects of the incorporated elements and their contents on the microstructure and mechanical performance of Al-Si-Fe alloys,the composition was optimized as Al-11Si-2.5Fe-2Mn-1.2Ni-0.4Cr(in wt.%).The optimized alloy was subsequently validated using PBF-LB,which exhibited favorable machinability,achieving a density of 99.8%.The room-temperature tensile strength of the PBF-LB manufactured Al-Si-Fe alloy reached(512.76±3.26)MPa,with a yield strength of(337.79±2.36)MPa and an elongation of(2.98±0.07)%.The enhanced room-temperature mechanical properties could be mainly attributed to the combined effects of fine-grain strengthening,solid solution strengthening,and precipitation strengthening.At 300°C,the high-temperature tensile strength of the developed alloy reached(222.47±6.41)MPa,with a yield strength of(164.25±11.40)MPa and an elongation of(8.88±0.33)%,outperforming those of existing alloys documented in the literature.The improved high-temperature mechanical performance was primarily provided by the three-dimensional network comprising cellular heat-resistant Al17(FeMnNiCr)4Si2 andα-Al(FeMn)Si phases.
基金Project(50971127)supported by the National Natural Science Foundation of China
文摘A Ti(Al,Si)3 diffusion coating was prepared on γ-TiAl alloy by cold sprayed Al?20Si alloy coating, followed by a heat-treatment. The isothermal and cyclic oxidation tests were conducted at 900 °C for 1000 h and 120 cycles to check the oxidation resistance of the coating. The microstructure and phase transformation of the coating before and after the oxidation were studied by SEM, XRD and EPMA. The results indicate that the diffusion coating shows good oxidation resistance. The mass gain of the diffusion coating is only a quarter of that of bare alloy. After oxidation, the diffusion coating is degraded into three layers: an inner TiAl2 layer, a two-phase intermediate layer composed of a Ti(Al,Si)3 matrix and Si-rich precipitates, and a porous layer because of the inter-diffusion between the coating and substrate.
基金Projects(CKJB201205,QKJB201202,YJK201307)supported by the Nanjing Institute of Technology,China
文摘The outermost coating with single phase Ni2Al3 was obtained on copper surface by electrodepositing nickel followed by slurry pack aluminizing at 800 °C for 12 h. The oxidation resistance and microstructure of the coating oxidized in ambient air at 1000 °C for 25-250 h were investigated using SEM, X-ray diffraction and optical microscope methods. The results show that the copper with single phase Ni2Al3 coating possesses the best high temperature oxidation resistance, and the mass gain of the coating is 1/15 that of pure copper and 1/2 that of nickel coating, respectively. The specimen surface after being oxidized for 25 h still comprises Ni2Al3 phase. However, when the time of oxidizing treatment increases to 50 h, the Ni Al phase is formed. It is also found that the Ni2Al3 phase completely turns into Ni Al phase after oxidizing treatment for 100 h and above. The Ni Al coating shows excellent high temperature oxidation resistance when oxidation time is 250 h.
文摘Fluoride mediated nano-sized ZSM-5 （ZSM-5-F） with a high Si/AI ratio of 181 was fabricated using a seed-induction method and evaluated the catalysis of the methanol to propylene （MTP） reaction. High propylene selectivity （45%） was similar to ZSM-5-OH synthesized via a hydroxide route. However, ZSM- 5-F showed much longer lifetime （305 h） compared with ZSM-5-OH （157 h） in spite of similar crystal size and aluminum content. Characterization by NH3-TPD. Py-IR, OH-IR, SEM, TG-DTA, XRD and 1H MAS NMR techniques indicated that the enhanced catalytic performance of ZSM-S-F is attributed to the fewer structural defects in the form of internal silanol groups and silanol nests.
基金Projects(51231002,51271054,51571058,50671023)supported by the National Natural Science Foundation of China
文摘To explore the effect of strain rate ε on the high temperature deformation characteristics of ultrafine-grained materials, the deformation and damage features as well as microstructures of ECAP-treated pure Al at different temperatures T and strain ratesε were systematically studied through compression tests and microscopic observations. The increase in ε eliminates strain softening at T≤473 K, and largely enhances the yield strength and flow stress at 473?573 K. The shear deformation dominates the plastic deformation of ECAP-treated Al. Many cracks along shear bands (SBs) are formed at T≥473 K and secondary SBs basically disappear at 1×10?3 s?1; however, at 1×10?2 s?1, cracks are only observed at temperature below 473 K, and secondary SBs become clearer at T≥473 K. The microstructures of ECAP-treated Al mainly consist of sub-grains (SGs). The increase in ε inhibits the SG growth, thus leading to the increases both in yield strength and flow stress at high temperatures.
基金Project(2014DFA51270)supported by the International Science and Technology Cooperation Program of ChinaProject(51421001)supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China
文摘The influences of high temperature pre-straining (HT-PS) on the natural aging and bake hardening of Al?Mg?Si alloys were investigated by Vickers microhardness measurements, differential scanning calorimetry (DSC) analysis and transmission electron microscopy (TEM) characterization. The results show that pre-straining at 170 °C immediately after quenching can effectively resolve the rather high T4 temper hardness caused by the conventional room temperature (RT) pre-straining treatment, and give a better bake hardening response (BHR) after paint-bake cycle. HT-PS 7% at 170 °C for 10 min is chosen as the optimum process as it provides lower T4 temper hardness and better BHR. The simultaneous introduction of dislocations and Cluster (2) can significantly suppress the natural aging and promote the precipitation of β″ phase, and reduce the effects of deformation hardening by dynamic recovery.
