To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that alt...To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that although the added Ti existed within Ti（Al1-xSix）3（0≤x≤0.15） phase,the shear strength and shear fracture surface of the developed Al-12Si-xTi brazes were quite similar to those of traditional Al-12Si braze due to the presence of similar microstructure of Al-Si eutectic microstructure with large volume fraction.So,small Ti addition（～1%） did not make the active brazes brittle and hard compared with the conventional Al-12Si braze.The measured melting range of each Al-12Si-xTi foil was very similar,i.e.,580-590 ℃,because the composition was close to that of eutectic.For wettability improvement,with increasing Ti content,the interfacial gap between the Al2O3 reinforcement and filler metal（R/M） could be eliminated,and the amount of the remainder of the active fillers on the composite substrate decreased after sessile drop test at 610 ℃ for 30 min.So,the wettability improvement became easy to observe repeatedly with increasing Ti content.Additionally,the amount and size of Ti（AlSi）3 phase were sensitive to the Ti content（before brazing） and Si content（after brazing）.展开更多
Si/SiC ceramic composite and lnvar alloy were successfidly joined by vacuum brazing using Ti5OCu-W filler metals into which W was added to release the thermal stress of the brazed joint. Microstructures of the brazed ...Si/SiC ceramic composite and lnvar alloy were successfidly joined by vacuum brazing using Ti5OCu-W filler metals into which W was added to release the thermal stress of the brazed joint. Microstructures of the brazed joints were irwestigated by scanning electron micrascope （SEM） and energy dispersive spectrometer （EDS）. The mechanical properties of the brazed joints were measured by shearing tests. The results showed that the brazed joints were composed of Ti-Cu phase, W phase and Ti-Si phase. W had no effect on the wettability and mobility of the .filler metals. The growth of Ti2 Cu phase was restrained, and the reaction between ceramic composite and filler metals was weakened. The specimen, brazed at 970°C for 5 rain, had the maximum shear strength of 108 MPa at room temperature.展开更多
Solid-state electrolytes(SSEs)are widely considered the essential components for upcoming rechargeable lithium-ion batteries owing to the potential for great safety and energy density.Among them,polymer solid-state el...Solid-state electrolytes(SSEs)are widely considered the essential components for upcoming rechargeable lithium-ion batteries owing to the potential for great safety and energy density.Among them,polymer solid-state electrolytes(PSEs)are competitive candidates for replacing commercial liquid electrolytes due to their flexibility,shape versatility and easy machinability.Despite the rapid development of PSEs,their practical application still faces obstacles including poor ionic conductivity,narrow electrochemical stable window and inferior mechanical strength.Polymer/inorganic composite electrolytes(PIEs)formed by adding ceramic fillers in PSEs merge the benefits of PSEs and inorganic solid-state electrolytes(ISEs),exhibiting appreciable comprehensive properties due to the abundant interfaces with unique characteristics.Some PIEs are highly compatible with high-voltage cathode and lithium metal anode,which offer desirable access to obtaining lithium metal batteries with high energy density.This review elucidates the current issues and recent advances in PIEs.The performance of PIEs was remarkably influenced by the characteristics of the fillers including type,content,morphology,arrangement and surface groups.We focus on the molecular interaction between different components in the composite environment for designing high-performance PIEs.Finally,the obstacles and opportunities for creating high-performance PIEs are outlined.This review aims to provide some theoretical guidance and direction for the development of PIEs.展开更多
Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combin...Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.展开更多
Aluminum matrix particulate reinforced composites are of significant interest to industry, but it’s difficult to provide stable properties for this group of material. The mechanical properties of metal matrix composi...Aluminum matrix particulate reinforced composites are of significant interest to industry, but it’s difficult to provide stable properties for this group of material. The mechanical properties of metal matrix composites are deeply influenced by the distribution of reinforcement particulates in the matrix. In this paper uniformity of SiC particles distribution in Al-based composites produced by stir casting and powder metallurgy technique is assessed. Analysis is carried out by means of classical and computer quantification metallographic image analysis methods. In addition, we suggest setting hardness distribution in cross section of samples as an indicator of reinforcement distribution uniformity in the matrix.展开更多
SiC p/6061Al alloy composite was welded by using TIG and pulsed-TIG welding (P-TIG) without addition of filler metal, or with addition of Al-Si or Al-Mg filler metal. The microstructure and properties of the weld were...SiC p/6061Al alloy composite was welded by using TIG and pulsed-TIG welding (P-TIG) without addition of filler metal, or with addition of Al-Si or Al-Mg filler metal. The microstructure and properties of the weld were investigated with XRD, OM, TEM, and MTS-810 testing system was used to observe the effect of different welding procedure and filler metals on the microstructure and properties of the weld. Thermodynamic of SiC-Al reaction was used to analyze the tendency of the reaction between SiC particle and Al matrix during welding. The results showed that the P-TIG tends to produce less plate-like Al 4C 3 precipitates than TIG; when welding with P-TIG, addition of Al-Si filler metal can not only prevent from formation of Al 4C 3, but also decrease hot crack sensitivity of weld; the tensile strength of joint of adding Al-Si filler metal is higher than that of adding Al-Mg filler metal. The SiC p/6061Al composite can be successfully welded by P-TIG with addition of Al-Si filler metal.展开更多
A novel method for preparing conductive polyethylene （PE） composites has been developed. In the method, the powder of low melting point metal alloy （LMPA） is filled into the PE matrix by using twin screw extruder ...A novel method for preparing conductive polyethylene （PE） composites has been developed. In the method, the powder of low melting point metal alloy （LMPA） is filled into the PE matrix by using twin screw extruder at a temperature below the melting point of the LMPA, and followed by a die drawing process at a temperature around the melting point of the metal alloy. It has been found that die drawing process, repeating the die drawing process and adding nano-fillers, such as montmorillonite （MMT） and multi-wall carbon nanotubes （MWCNTs）, all help reduce the metal particle size in the PE matrix, thus improve the conductivity of the composite. The conductivity improvement is attributed to an increased number of the smaller metal particles. Therefore, conductive composites of polymer/metal alloy/nano-filler with high conductivity are possible to be prepared by using the new method.展开更多
As a structural and functional material with excellent properties,ceramics play an extremely important role in a wide range of industries,including life and production.To expand the range of applications for ceramic m...As a structural and functional material with excellent properties,ceramics play an extremely important role in a wide range of industries,including life and production.To expand the range of applications for ceramic materials,ceramics are often joined to metals and then used.Among the physical and chemical joining methods of ceramics to metals,the AMB method is efficient and simple,suitable for industrial applications,and has been a hot topic of research.However,due to the problems of residual stresses caused by the large difference in thermal expansion coefficients between ceramic and metal brazing,composite fillers have become a very worthwhile solution by regulating the physical properties of the brazing material and improving the weld structure.This review describes the wetting principle and application of Ag‒Cu‒Ti active metal filler in the field of ceramic joining,with emphasis on the current stage of composite filler,and discusses the influence on the former brazing properties and organization after the introduction of dissimilar materials.展开更多
The ever-growing demand for next-generation high-energy-density devices drives the development of lithium metal batteries with enough safety and high performance,in which quasi-solid-state composite electrolytes(QSCEs...The ever-growing demand for next-generation high-energy-density devices drives the development of lithium metal batteries with enough safety and high performance,in which quasi-solid-state composite electrolytes(QSCEs)with high ionic conductivity and lithium ion transference number(urn:x-wiley:1001604X:media:cjoc202300232:cjoc202300232-math-0001)are highly desirable.Herein,we successfully synthesize a kind of two-dimensional(2D)molecular brush(GO-g-PFIL)via grafting poly(ionic liquid)side-chain(poly(3-(3,3,4,4,4-pentafluorobutyl)-1-vinyl-1H-imidazol-3-ium bis(trifluoromethanesulfonyl)imide),denoted as PFIL)on the surface of 2D graphene oxide(GO)sheet.GO-g-PFIL is used as multifunctional filler to prepare novel composite membranes and corresponding QSCEs(e.g.,QSCE-PH/GPFIL3/P).The as-obtained QSCE-PH/GPFIL3/P integrates features of PFIL side-chain-enhanced lithium ion conduction,poly(vinylidene fluoride-co-hexafluoropropene)backbone-induced flexibility,and GO-strengthened mechanical property.As a result,our ultrathin(21μm)self-supporting QSCE-PH/GPFIL3/P exhibits high ionic conductivity(3.24×10^(−4)S·cm^(−1))and excellent urn:x-wiley:1001604X:media:cjoc202300232:cjoc202300232-math-0002(0.82)at room temperature,and Li/LFP full cell with QSCE-PH/GPFIL3/P shows superior rate performance(high specific capacities of 79 mAh·g^(−1)at 30°C and 5 C)and excellent cycling performance(high capacity retention of 91%after 500 cycles at 80°C and 1 C).展开更多
The effects of filler metal （FM） composition on inclusions and inclusion defects for ER NiCrFe-7 weldments have been investigated and analyzed. Results show that as Al, Ti content in FM increases from 0.14 wt% Al, 0...The effects of filler metal （FM） composition on inclusions and inclusion defects for ER NiCrFe-7 weldments have been investigated and analyzed. Results show that as Al, Ti content in FM increases from 0.14 wt% Al, 0.30 wt% Ti to 0.42 wt% Al, 0.92 wt% Ti, the Al, Ti reduction will increase during welding. Inclusion defects （point-like defects named by welding workers） are prone to form in the high Al, Ti content weldments. Inclusion defects with Mg, Ca, Al, and Ti as major metallic elements have been found on the surface and interior of the weldments, as Al, Ti content in FM is over 0.29 wt% Al, 0.62 wt% Ti. Less -ri content in FM cannot prevent ductility-dip-cracking （DDC） through producing enough intragranular precipitates and lessening intergranular M23C6 precipitates. Nb can be used to replace Ti to reduce the sensitivity of the DDC in the NiCrFe-7 alloy weldments.展开更多
基金Project(50875199) supported by the National Natural Science Foundation of ChinaProject supported by State Key Laboratory of Advanced Welding and Joining,China
文摘To improve the wettability of Al metal matrix composites（Al-MMCs） by common filler metals,Al-12Si-xTi（x=0.1,0.5,1,3.0;mass fraction,%） system active ternary filler metals were prepared.It was demonstrated that although the added Ti existed within Ti（Al1-xSix）3（0≤x≤0.15） phase,the shear strength and shear fracture surface of the developed Al-12Si-xTi brazes were quite similar to those of traditional Al-12Si braze due to the presence of similar microstructure of Al-Si eutectic microstructure with large volume fraction.So,small Ti addition（～1%） did not make the active brazes brittle and hard compared with the conventional Al-12Si braze.The measured melting range of each Al-12Si-xTi foil was very similar,i.e.,580-590 ℃,because the composition was close to that of eutectic.For wettability improvement,with increasing Ti content,the interfacial gap between the Al2O3 reinforcement and filler metal（R/M） could be eliminated,and the amount of the remainder of the active fillers on the composite substrate decreased after sessile drop test at 610 ℃ for 30 min.So,the wettability improvement became easy to observe repeatedly with increasing Ti content.Additionally,the amount and size of Ti（AlSi）3 phase were sensitive to the Ti content（before brazing） and Si content（after brazing）.
文摘Si/SiC ceramic composite and lnvar alloy were successfidly joined by vacuum brazing using Ti5OCu-W filler metals into which W was added to release the thermal stress of the brazed joint. Microstructures of the brazed joints were irwestigated by scanning electron micrascope （SEM） and energy dispersive spectrometer （EDS）. The mechanical properties of the brazed joints were measured by shearing tests. The results showed that the brazed joints were composed of Ti-Cu phase, W phase and Ti-Si phase. W had no effect on the wettability and mobility of the .filler metals. The growth of Ti2 Cu phase was restrained, and the reaction between ceramic composite and filler metals was weakened. The specimen, brazed at 970°C for 5 rain, had the maximum shear strength of 108 MPa at room temperature.
基金the National Natural Science Foundation of China(Nos.22279070,U21A20170 and 22175106)the Ministry of Science and Technology of China(Nos.2019YFA0705703,2021YFB2501900 and 2019YFE0100200)+1 种基金the Tsinghua University Initiative Scientific Research Program(20223080001)the Tsinghua-Foshan Innovation Special Fund(2021THFS0216)。
文摘Solid-state electrolytes(SSEs)are widely considered the essential components for upcoming rechargeable lithium-ion batteries owing to the potential for great safety and energy density.Among them,polymer solid-state electrolytes(PSEs)are competitive candidates for replacing commercial liquid electrolytes due to their flexibility,shape versatility and easy machinability.Despite the rapid development of PSEs,their practical application still faces obstacles including poor ionic conductivity,narrow electrochemical stable window and inferior mechanical strength.Polymer/inorganic composite electrolytes(PIEs)formed by adding ceramic fillers in PSEs merge the benefits of PSEs and inorganic solid-state electrolytes(ISEs),exhibiting appreciable comprehensive properties due to the abundant interfaces with unique characteristics.Some PIEs are highly compatible with high-voltage cathode and lithium metal anode,which offer desirable access to obtaining lithium metal batteries with high energy density.This review elucidates the current issues and recent advances in PIEs.The performance of PIEs was remarkably influenced by the characteristics of the fillers including type,content,morphology,arrangement and surface groups.We focus on the molecular interaction between different components in the composite environment for designing high-performance PIEs.Finally,the obstacles and opportunities for creating high-performance PIEs are outlined.This review aims to provide some theoretical guidance and direction for the development of PIEs.
基金supported by the Science and Technology Commission of Shanghai Municipality(No.19DZ2270100),China。
文摘Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design.
文摘Aluminum matrix particulate reinforced composites are of significant interest to industry, but it’s difficult to provide stable properties for this group of material. The mechanical properties of metal matrix composites are deeply influenced by the distribution of reinforcement particulates in the matrix. In this paper uniformity of SiC particles distribution in Al-based composites produced by stir casting and powder metallurgy technique is assessed. Analysis is carried out by means of classical and computer quantification metallographic image analysis methods. In addition, we suggest setting hardness distribution in cross section of samples as an indicator of reinforcement distribution uniformity in the matrix.
文摘SiC p/6061Al alloy composite was welded by using TIG and pulsed-TIG welding (P-TIG) without addition of filler metal, or with addition of Al-Si or Al-Mg filler metal. The microstructure and properties of the weld were investigated with XRD, OM, TEM, and MTS-810 testing system was used to observe the effect of different welding procedure and filler metals on the microstructure and properties of the weld. Thermodynamic of SiC-Al reaction was used to analyze the tendency of the reaction between SiC particle and Al matrix during welding. The results showed that the P-TIG tends to produce less plate-like Al 4C 3 precipitates than TIG; when welding with P-TIG, addition of Al-Si filler metal can not only prevent from formation of Al 4C 3, but also decrease hot crack sensitivity of weld; the tensile strength of joint of adding Al-Si filler metal is higher than that of adding Al-Mg filler metal. The SiC p/6061Al composite can be successfully welded by P-TIG with addition of Al-Si filler metal.
文摘A novel method for preparing conductive polyethylene （PE） composites has been developed. In the method, the powder of low melting point metal alloy （LMPA） is filled into the PE matrix by using twin screw extruder at a temperature below the melting point of the LMPA, and followed by a die drawing process at a temperature around the melting point of the metal alloy. It has been found that die drawing process, repeating the die drawing process and adding nano-fillers, such as montmorillonite （MMT） and multi-wall carbon nanotubes （MWCNTs）, all help reduce the metal particle size in the PE matrix, thus improve the conductivity of the composite. The conductivity improvement is attributed to an increased number of the smaller metal particles. Therefore, conductive composites of polymer/metal alloy/nano-filler with high conductivity are possible to be prepared by using the new method.
基金the National Natural Science Foundation of China(Grant Nos.51971204 and 52171081)the Zhejiang Provincial Natural Science Foundation of China(Grant Nos.LY19E010006 and LY21E010005).
文摘As a structural and functional material with excellent properties,ceramics play an extremely important role in a wide range of industries,including life and production.To expand the range of applications for ceramic materials,ceramics are often joined to metals and then used.Among the physical and chemical joining methods of ceramics to metals,the AMB method is efficient and simple,suitable for industrial applications,and has been a hot topic of research.However,due to the problems of residual stresses caused by the large difference in thermal expansion coefficients between ceramic and metal brazing,composite fillers have become a very worthwhile solution by regulating the physical properties of the brazing material and improving the weld structure.This review describes the wetting principle and application of Ag‒Cu‒Ti active metal filler in the field of ceramic joining,with emphasis on the current stage of composite filler,and discusses the influence on the former brazing properties and organization after the introduction of dissimilar materials.
基金This work was supported by the projects of National Key Research and Development Program of China(2021YFF0500600)National Natural Science Foundation of China(51925308)+1 种基金Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23yxqntdo02)Natural Science Foundation of Guangdong Province(2023A1515030160,2022A1515011778).
文摘The ever-growing demand for next-generation high-energy-density devices drives the development of lithium metal batteries with enough safety and high performance,in which quasi-solid-state composite electrolytes(QSCEs)with high ionic conductivity and lithium ion transference number(urn:x-wiley:1001604X:media:cjoc202300232:cjoc202300232-math-0001)are highly desirable.Herein,we successfully synthesize a kind of two-dimensional(2D)molecular brush(GO-g-PFIL)via grafting poly(ionic liquid)side-chain(poly(3-(3,3,4,4,4-pentafluorobutyl)-1-vinyl-1H-imidazol-3-ium bis(trifluoromethanesulfonyl)imide),denoted as PFIL)on the surface of 2D graphene oxide(GO)sheet.GO-g-PFIL is used as multifunctional filler to prepare novel composite membranes and corresponding QSCEs(e.g.,QSCE-PH/GPFIL3/P).The as-obtained QSCE-PH/GPFIL3/P integrates features of PFIL side-chain-enhanced lithium ion conduction,poly(vinylidene fluoride-co-hexafluoropropene)backbone-induced flexibility,and GO-strengthened mechanical property.As a result,our ultrathin(21μm)self-supporting QSCE-PH/GPFIL3/P exhibits high ionic conductivity(3.24×10^(−4)S·cm^(−1))and excellent urn:x-wiley:1001604X:media:cjoc202300232:cjoc202300232-math-0002(0.82)at room temperature,and Li/LFP full cell with QSCE-PH/GPFIL3/P shows superior rate performance(high specific capacities of 79 mAh·g^(−1)at 30°C and 5 C)and excellent cycling performance(high capacity retention of 91%after 500 cycles at 80°C and 1 C).
基金support from the key research program of the Chinese Academy of Sciences(Grant No.KGZD-EW-XXX-2)
文摘The effects of filler metal （FM） composition on inclusions and inclusion defects for ER NiCrFe-7 weldments have been investigated and analyzed. Results show that as Al, Ti content in FM increases from 0.14 wt% Al, 0.30 wt% Ti to 0.42 wt% Al, 0.92 wt% Ti, the Al, Ti reduction will increase during welding. Inclusion defects （point-like defects named by welding workers） are prone to form in the high Al, Ti content weldments. Inclusion defects with Mg, Ca, Al, and Ti as major metallic elements have been found on the surface and interior of the weldments, as Al, Ti content in FM is over 0.29 wt% Al, 0.62 wt% Ti. Less -ri content in FM cannot prevent ductility-dip-cracking （DDC） through producing enough intragranular precipitates and lessening intergranular M23C6 precipitates. Nb can be used to replace Ti to reduce the sensitivity of the DDC in the NiCrFe-7 alloy weldments.
