Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic ...Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.展开更多
Mg alloys with a combination of high strength and excellent ductility are increasingly required for structural applications.This study investigates the influence of advanced processing techniques on the mechanical pro...Mg alloys with a combination of high strength and excellent ductility are increasingly required for structural applications.This study investigates the influence of advanced processing techniques on the mechanical properties and microstructural evolution of Mg-Gd-Y-Zn-Zr alloys.Utilizing a combination of double extrusion and stepwise hot rolling followed by aging treatments,significant enhancements in the mechanical performance of these alloys are demonstrated.The processing techniques applied lead to notable refinement in grain-size and modifications in the microstructure,including the transformation of LPSO phases from 18R to 24R and the dispersion of β phase particles.These microstructural transformations contribute to a substantial increase in yield-strength,ultimate-tensile-strength,and ductility.Furthermore,findings reveal that these improvements are also supported by alterations in material texture,which influence dislocation dynamics as indicated by changes in Kernel Average Misorientation(KAM)values.The combined effect of grain boundary(GB)strengthening,phase distribution,and texture modification elucidates the observed mechanical enhancements.This research provides valuable insights into the design and optimization of Mg-Gd-Y-Zn-Zr alloys for critical applications in aerospace and automotive industries where high strength and ductility are paramount.展开更多
The insulin-like growth factor 1（IGF1） gene is a member of the group of somatotropin axis genes that play a significant role in cell proliferation and growth of muscles. Here, we searched for polymorphisms in buffal...The insulin-like growth factor 1（IGF1） gene is a member of the group of somatotropin axis genes that play a significant role in cell proliferation and growth of muscles. Here, we searched for polymorphisms in buffalo IGF1 and found two novel single nucleotide polymorphisms（SNPs）, G64 A and G280A, in the noncoding sequences of exon 1 and exon 4, respectively. Statistical analysis of different genotypes showed that the individuals with GG genotypes had significantly（P〈0.05） higher body weight（BW） and average daily gain（ADG） than those with other genotypes at ages of 3–6 months in G64A SNP and 6–9 months in G280A SNP. The combined genotypes of these two SNPs produced three haplotypes, GG/GG, AG/AG, and AA/AA, which were significantly associated（P〈0.0001） with BW and ADG at an age from 3 to 12 months. Buffaloes with the homozygous GG/GG haplotype showed higher growth performance than other buffaloes. The two SNPs were correlated with m RNA levels of IGF1 and IGF1 receptor（IGF1 R） in semitendinosus muscle as well as with the serum concentration level of IGF1. Also, buffaloes with GG/GG haplotype showed higher m RNA and serum concentration levels. The data revealed that these two SNPs could be valuable genetic markers for selection of Egyptian buffaloes for better performance in the population.展开更多
基金financially and technically supported by the National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact,Beijing Institute of Technology,China(No.WDZC2024-1)。
文摘Cryogenic rolling impacts on microstructure and mechanical properties of spray-formed 7055(SF-7055)Al alloy were investigated.Results show that with the increase of the reduction from 20%to 80%,the grain of cryogenic rolled SF-7055 Al alloy is elongated to form a fiber texture.Numerous proliferating dislocations in the microstructure accumulate into dislocation walls and cells,and eventually form subgrains.These subgrain boundaries divide the original grain,thereby reducing the grain size.Under severe deformation conditions,they even enable the formation of nanograins.Meanwhile,the Cu-rich precipitates in the matrix are also broken and refined under the action of large rolling stress.In the process of cryogenic rolling,the tensile strength and hardness of SF-7055 Al alloy gradually increase,while the plasticity decreases.Moreover,the fracture morphology of cryogenic rolled SF-7055 Al alloy gradually transforms to the ductile and quasi-cleavage hybrid fracture characteristics with increased reduction.
基金financially supported by the financial supports from the National Natural Science Foundation of China(Grant No.52027805).
文摘Mg alloys with a combination of high strength and excellent ductility are increasingly required for structural applications.This study investigates the influence of advanced processing techniques on the mechanical properties and microstructural evolution of Mg-Gd-Y-Zn-Zr alloys.Utilizing a combination of double extrusion and stepwise hot rolling followed by aging treatments,significant enhancements in the mechanical performance of these alloys are demonstrated.The processing techniques applied lead to notable refinement in grain-size and modifications in the microstructure,including the transformation of LPSO phases from 18R to 24R and the dispersion of β phase particles.These microstructural transformations contribute to a substantial increase in yield-strength,ultimate-tensile-strength,and ductility.Furthermore,findings reveal that these improvements are also supported by alterations in material texture,which influence dislocation dynamics as indicated by changes in Kernel Average Misorientation(KAM)values.The combined effect of grain boundary(GB)strengthening,phase distribution,and texture modification elucidates the observed mechanical enhancements.This research provides valuable insights into the design and optimization of Mg-Gd-Y-Zn-Zr alloys for critical applications in aerospace and automotive industries where high strength and ductility are paramount.
基金Project supported by the Science Technology Development Fund(STDF,No.2585),Ministry of Scientific Research,Egypt
文摘The insulin-like growth factor 1（IGF1） gene is a member of the group of somatotropin axis genes that play a significant role in cell proliferation and growth of muscles. Here, we searched for polymorphisms in buffalo IGF1 and found two novel single nucleotide polymorphisms（SNPs）, G64 A and G280A, in the noncoding sequences of exon 1 and exon 4, respectively. Statistical analysis of different genotypes showed that the individuals with GG genotypes had significantly（P〈0.05） higher body weight（BW） and average daily gain（ADG） than those with other genotypes at ages of 3–6 months in G64A SNP and 6–9 months in G280A SNP. The combined genotypes of these two SNPs produced three haplotypes, GG/GG, AG/AG, and AA/AA, which were significantly associated（P〈0.0001） with BW and ADG at an age from 3 to 12 months. Buffaloes with the homozygous GG/GG haplotype showed higher growth performance than other buffaloes. The two SNPs were correlated with m RNA levels of IGF1 and IGF1 receptor（IGF1 R） in semitendinosus muscle as well as with the serum concentration level of IGF1. Also, buffaloes with GG/GG haplotype showed higher m RNA and serum concentration levels. The data revealed that these two SNPs could be valuable genetic markers for selection of Egyptian buffaloes for better performance in the population.
