The topic of high-entropy alloys is one of the focus for both physics and materials research.High-entropy alloys were usually defined as solid solution alloys,while the solid solution is different from the traditional...The topic of high-entropy alloys is one of the focus for both physics and materials research.High-entropy alloys were usually defined as solid solution alloys,while the solid solution is different from the traditional terminal solid solution,because the solid solution without solvent element is the dominant one.The discovery of high-entropy alloys greatly extended the composition space and the possibility of creating unique micro-and nano-level structures,which can meet the demands of lightweight and dynamic applications.The relationship between the phases and the parameters for the high-entropy alloys is rather complex.The data driving design can screen the specific high-entropy alloys.The correlation between the composition and properties of highentropy alloys can be discovered by material genetic engineering and data science.展开更多
In the present study, it is expected to tailor the microstructural features, martensitic transformation temperatures and mechanical properties of Ti-V-Al shape memory alloys through adding Sn alloying elements, which ...In the present study, it is expected to tailor the microstructural features, martensitic transformation temperatures and mechanical properties of Ti-V-Al shape memory alloys through adding Sn alloying elements, which further expands their applications. Sn addition results in the monotonous rising of average valence electron number (e/a). In proportion, the single α″ martensite phase directly evolves into merely β parent phase in present Ti-V-Al-based shape memory alloys, as Sn content increases from 0.5 to 5.0 at.%. Meanwhile, Sn addition causes the reduction in the grain size. Combined with transmission electron microscopy (TEM) observation and d electron theory analysis, it can be speculated that Sn addition can suppress the precipitation of ω phase. With increasing Sn content, fracture strength invariably decreases from 962 to 792 MPa, whereas the yield strength firstly decreases and then increases. The lowest yield stress for the stress-induced martensitic transformation of 220 MPa can be obtained in Ti-V-Al shape memory alloy by adding 3.0 at.% Sn. By optimizing 1.0 at.% Sn, the excellent ductility with a largest elongation of 42.1% can be gained in Ti-V-Al shape memory alloy, which is larger than that of the reported Ti-V-Al-based shape memory alloys. Besides, as a result of solution strengthening and grain refinement, Ti-V-Al-based shape memory alloy with 5.0 at.% Sn possesses the highest yield strength, further contributing to the excellent strain recovery characteristics with 4% fully recoverable strain.展开更多
On 25th,April,Jinfei Kaida signed the agreement with management committee of Jinhua Economic and Technological Development Zone,planning to invest in the local construction of smart manufacturing project of lightweigh...On 25th,April,Jinfei Kaida signed the agreement with management committee of Jinhua Economic and Technological Development Zone,planning to invest in the local construction of smart manufacturing project of lightweight aluminium alloy auto rim with the annual production of 3 million pieces.展开更多
The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of this work. It takes a load-dependent design of components and as...The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of this work. It takes a load-dependent design of components and assemblies, for example, based on the composition of different construction materials or a targeted setting of component areas with specified characteristics to fully exploit the lightweight potential when substituting conventionally used materials. Different process chains for the manufacturing of roll-formed long products made of magnesium alloys and high-strength steels with locally defined properties will be presented in this paper. Depending on the kind of material to be formed and the desired product characteristics, different temperature managements are needed for capable processes. Due to limited formability at room temperature, magnesium alloys require a heating of the forming zones above 200–225 °C throughout the bending process in order to activate additional gliding planes and to avoid any failures in the radii. The realization of local hardening effects requires at least one process-integrated heat treatment when roll forming manganese–boron steels. For both processes, it is imperative to realize a heating and cooling down or quenching appropriate for the manufacturing of long products with the required quality. Additionally, proper line speeds that allow a continuously operated economical production have to be considered. Research results including design, FEA, realization and experimentation of the mentioned process chains and strategies will be described in detail.展开更多
基金supports from the National Natural Science Foundation of China(Grant No.52273280)the financial support from the National Natural Science Foundation of China(Grant No.52271110)Creative Research Groups of China(Grant No.51921001)。
文摘The topic of high-entropy alloys is one of the focus for both physics and materials research.High-entropy alloys were usually defined as solid solution alloys,while the solid solution is different from the traditional terminal solid solution,because the solid solution without solvent element is the dominant one.The discovery of high-entropy alloys greatly extended the composition space and the possibility of creating unique micro-and nano-level structures,which can meet the demands of lightweight and dynamic applications.The relationship between the phases and the parameters for the high-entropy alloys is rather complex.The data driving design can screen the specific high-entropy alloys.The correlation between the composition and properties of highentropy alloys can be discovered by material genetic engineering and data science.
基金financial support from the National Natural Science Foundation of China(Nos.52101231,52101232 and 51871079)the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing(Yantai)(No.AMGM2021F09)+1 种基金the Natural Science Foundation of Shandong Province,China(No.ZR2021QE044)the Gansu Province Science and Technology Foundation for Youths(No.21JR7RA088).
文摘In the present study, it is expected to tailor the microstructural features, martensitic transformation temperatures and mechanical properties of Ti-V-Al shape memory alloys through adding Sn alloying elements, which further expands their applications. Sn addition results in the monotonous rising of average valence electron number (e/a). In proportion, the single α″ martensite phase directly evolves into merely β parent phase in present Ti-V-Al-based shape memory alloys, as Sn content increases from 0.5 to 5.0 at.%. Meanwhile, Sn addition causes the reduction in the grain size. Combined with transmission electron microscopy (TEM) observation and d electron theory analysis, it can be speculated that Sn addition can suppress the precipitation of ω phase. With increasing Sn content, fracture strength invariably decreases from 962 to 792 MPa, whereas the yield strength firstly decreases and then increases. The lowest yield stress for the stress-induced martensitic transformation of 220 MPa can be obtained in Ti-V-Al shape memory alloy by adding 3.0 at.% Sn. By optimizing 1.0 at.% Sn, the excellent ductility with a largest elongation of 42.1% can be gained in Ti-V-Al shape memory alloy, which is larger than that of the reported Ti-V-Al-based shape memory alloys. Besides, as a result of solution strengthening and grain refinement, Ti-V-Al-based shape memory alloy with 5.0 at.% Sn possesses the highest yield strength, further contributing to the excellent strain recovery characteristics with 4% fully recoverable strain.
文摘On 25th,April,Jinfei Kaida signed the agreement with management committee of Jinhua Economic and Technological Development Zone,planning to invest in the local construction of smart manufacturing project of lightweight aluminium alloy auto rim with the annual production of 3 million pieces.
基金the Federal Government of Germanythe Free State of Saxony namely within the programs European Regional Development Fund and Innovative Regional Growth Cores
文摘The processing of innovative lightweight materials to sheet metal components and assemblies with globally or locally defined properties is the object of this work. It takes a load-dependent design of components and assemblies, for example, based on the composition of different construction materials or a targeted setting of component areas with specified characteristics to fully exploit the lightweight potential when substituting conventionally used materials. Different process chains for the manufacturing of roll-formed long products made of magnesium alloys and high-strength steels with locally defined properties will be presented in this paper. Depending on the kind of material to be formed and the desired product characteristics, different temperature managements are needed for capable processes. Due to limited formability at room temperature, magnesium alloys require a heating of the forming zones above 200–225 °C throughout the bending process in order to activate additional gliding planes and to avoid any failures in the radii. The realization of local hardening effects requires at least one process-integrated heat treatment when roll forming manganese–boron steels. For both processes, it is imperative to realize a heating and cooling down or quenching appropriate for the manufacturing of long products with the required quality. Additionally, proper line speeds that allow a continuously operated economical production have to be considered. Research results including design, FEA, realization and experimentation of the mentioned process chains and strategies will be described in detail.