In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HE...In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.展开更多
Achieving high-quality joining of silicon carbide(SiC)ceramics and Inconel 718 alloy has become a significant challenge for the brazing process,which is strongly dependent on the filler material.A novel composite inte...Achieving high-quality joining of silicon carbide(SiC)ceramics and Inconel 718 alloy has become a significant challenge for the brazing process,which is strongly dependent on the filler material.A novel composite interlayer consisting of high-entropy alloys(HEAs),HEA/Ni/HEA,was proposed to reduce the formation of intermetallic compounds in the brazed joints of SiC ceramics and Inconel 718 alloy.A reliable SiC/Inconel 718 brazed joint was produced at 1120℃ for 60 min.The results showed a significant reduction in the number of NiSi compounds in the brazed joint.The brazing seam structure near SiC side was filled with face-centered cubic phases with good plasticity and soft Cu-rich phases due to the high-entropy effect,which effectively suppressed the formation of intermetallic compounds.The maximum shear strength of the brazed joint reached 88 MPa,showing excellent tensile strength.The results provide a valuable basis for improving the joint quality of SiC ceramics and metals by adding high-entropy alloy fillers.展开更多
The interlayer bonding properties are normally unsatisfying for 3D printed composites owing to the layer-by-layer formation process.In this study,low-pressure annealing was performed on 3D printed carbon fiber reinfor...The interlayer bonding properties are normally unsatisfying for 3D printed composites owing to the layer-by-layer formation process.In this study,low-pressure annealing was performed on 3D printed carbon fiber reinforced polyether ether ketone(CF/PEEK)to improve the interlayer bonding strength.The effects of annealing parameters on the mechanical properties and microstructure were studied.The results showed that the interlaminar shear strength(ILSS)of CF/PEEK improved by up to 55.4%after annealing.SEM and𝜇-CT were also applied to reveal the reinforcing mechanism.This improvement could mainly be attributed to the increased crystallinity of the CF/PEEK after annealing.Additionally,annealing reduced the porosity of the printed CF/PEEK and improved the fiber-resin interface.This resulted in a reduction in the stress concentration areas during loading,thereby enhancing the interlayer bonding strength of CF/PEEK.展开更多
基金financial supports from the National Natural Science Foundation of China (No. 51875062)China Postdoctoral Science Foundation (No. 2021M700567)。
文摘In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can effectively inhibit the interfacial diffusion between Al and Mg,which is conducive to the formation of solid solution,especially when the thickness of HEA is 800 nm.With the increase of casting temperature from 720 ℃ to 730 ℃,740℃,and 750 ℃,α-Al(Mg),α-Al(Mg)+Al3Mg2,Al3Mg2+Al12Mg17,and Al12Mg17+δ-Mg are formed at the interface of Ti/Mg bimetal,respectively.When the thickness of the HEA layer is 800 nm and the pouring temperature is 720 ℃,the bonding strength of the Ti/Mg bimetal can reach the maximum of 93.6 MPa.
基金financially supported by the National Natural Science Foundation of China(52074017)Beijing Natural Science Foundation(3232005)+3 种基金2024 BJUT Introducing Intelligence Breeding Project(2024DL01)China-CEEC Joint Education Project for Higher Education(2021113)State Key Laboratory of Advanced Brazing Filler Metals and Technology(SKLABFMT202004)State Key Laboratory of Advanced Welding and Joining(AWJ-20-M01).
文摘Achieving high-quality joining of silicon carbide(SiC)ceramics and Inconel 718 alloy has become a significant challenge for the brazing process,which is strongly dependent on the filler material.A novel composite interlayer consisting of high-entropy alloys(HEAs),HEA/Ni/HEA,was proposed to reduce the formation of intermetallic compounds in the brazed joints of SiC ceramics and Inconel 718 alloy.A reliable SiC/Inconel 718 brazed joint was produced at 1120℃ for 60 min.The results showed a significant reduction in the number of NiSi compounds in the brazed joint.The brazing seam structure near SiC side was filled with face-centered cubic phases with good plasticity and soft Cu-rich phases due to the high-entropy effect,which effectively suppressed the formation of intermetallic compounds.The maximum shear strength of the brazed joint reached 88 MPa,showing excellent tensile strength.The results provide a valuable basis for improving the joint quality of SiC ceramics and metals by adding high-entropy alloy fillers.
基金This work was supported by Basic Strengthening Program of China(Grant No.2021-JCJQ-JJ-0186)National Natural Science Foundation of China(Grant No.52205383)+1 种基金Natural Science Foundation of Jiangsu(Grant Nos.BK20220895&BK20210314)Postdoctoral Science Foundation of China(Grant No.2021M691568).
文摘The interlayer bonding properties are normally unsatisfying for 3D printed composites owing to the layer-by-layer formation process.In this study,low-pressure annealing was performed on 3D printed carbon fiber reinforced polyether ether ketone(CF/PEEK)to improve the interlayer bonding strength.The effects of annealing parameters on the mechanical properties and microstructure were studied.The results showed that the interlaminar shear strength(ILSS)of CF/PEEK improved by up to 55.4%after annealing.SEM and𝜇-CT were also applied to reveal the reinforcing mechanism.This improvement could mainly be attributed to the increased crystallinity of the CF/PEEK after annealing.Additionally,annealing reduced the porosity of the printed CF/PEEK and improved the fiber-resin interface.This resulted in a reduction in the stress concentration areas during loading,thereby enhancing the interlayer bonding strength of CF/PEEK.
