In view of high strength and poor impact toughness of the high-zinc magnesium alloys,the method of micro-alloying was adopted to improve the impact-toughness of Mg-10Zn-5Al high zinc magnesium alloys by adjusting the ...In view of high strength and poor impact toughness of the high-zinc magnesium alloys,the method of micro-alloying was adopted to improve the impact-toughness of Mg-10Zn-5Al high zinc magnesium alloys by adjusting the addition of Sb.The results show that:the dystectic Mg3Sb2 particles formed by Sb and Mg are distributed in the front of dendrite,restrain the growth of the secondary phase and then change the morphology of the secondary phases,which refines the matrix in some extent and improves the impact-toughness of the alloy significantly.But with further increase of Sb addition,Mg3Sb2 particles congregate and form needle-like Mg3Sb2 phase,which dissevers the matrix and leads to the reduction of the strength and impact-toughness of the alloys.Hence,the mechanical prosperities of ZA105 high zinc magnesium alloy are significantly improved with appropriate Sb addition,which provides a new way to extend the application fields of high zinc magnesium alloy.展开更多
In view of the mechanics characteristic of cemented tailings backfill(CTB)at early age,the separation Hopkinson pressure bar test device was used to explore the effects of curing age and impact energy.A total of 48 CT...In view of the mechanics characteristic of cemented tailings backfill(CTB)at early age,the separation Hopkinson pressure bar test device was used to explore the effects of curing age and impact energy.A total of 48 CTB samples with diameter of 50 mm and length of 25 mm were prepared with curing ages of 3,5,7 and 9 d.Impact tests under different impact energy(10,20,30 and 40 J)were carried out.The microstructure of CTB at different ages was analyzed by scanning electron microscopy(SEM).The results show that,the curing age mainly affects the mechanical properties and internal structure of early-age CTB.With increasing curing age,the mechanical properties of early-age CTB change from viscoelasticity to brittleness.The impact energy mainly affects the response of dynamic peak compressive strength to strain rate.Under low strain rate,the structure of CTB is broken,but still has bearing capacity,affecting the formation of later strength.It is concluded that the structural loses completely under the action of high strain rate.Therefore,the control of impact energy and the protection of curing age should be fully considered in actual production process.展开更多
Reference to the domestic and foreign relevant technical data, the paper design and manufacture enamel materials with a temperature resistant shock resistance and acid resistance excellent chemical stability, research...Reference to the domestic and foreign relevant technical data, the paper design and manufacture enamel materials with a temperature resistant shock resistance and acid resistance excellent chemical stability, research on microscopic morphology of the enamel surface by scanning electron microscope, the experiment results showed： mill addition certain amount of zirconium silicate crystal in enamel material, enable enamel material to form composite materials of amorphous material and zirconium silicate crystals, it can effectively improve its temperature shock property; it is necessary to improve the enamel material temperature resistance shock property, but also maintain its excellent acid resistance, there is a optimal weight range mill addition into zirconium silicate crystal.展开更多
In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layer...In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layers configuration on the impact resistance is investigated by low-velocity impact test,and the impact failure mechanism of the 3D printed composites is explored by microscopic observations and finite element(FE)simulation analysis.The results show that the 3D printed multi-layered composite with SCF layers distributed in the middle(HFA)exhibits higher impact resistant performance than the specimens with alternating SCF/CCF layers(HFB)and CCF layers distributed in the middle(HFC).The effect of CCF/SCF layers proportion on the impact performance is also studied by FE simulation,and the results show that the specimen with a CCF/SCF proportion of 7.0 exhibits the highest impact strength.展开更多
基金Project(50571073) supported by the National Natural Science Foundation of ChinaProjects(2009011028-3,20051052) supported by the Natural Science Foundation of Shanxi Province,ChinaProject(07010713) supported by Higher School Student Project of Taiyuan City,China
文摘In view of high strength and poor impact toughness of the high-zinc magnesium alloys,the method of micro-alloying was adopted to improve the impact-toughness of Mg-10Zn-5Al high zinc magnesium alloys by adjusting the addition of Sb.The results show that:the dystectic Mg3Sb2 particles formed by Sb and Mg are distributed in the front of dendrite,restrain the growth of the secondary phase and then change the morphology of the secondary phases,which refines the matrix in some extent and improves the impact-toughness of the alloy significantly.But with further increase of Sb addition,Mg3Sb2 particles congregate and form needle-like Mg3Sb2 phase,which dissevers the matrix and leads to the reduction of the strength and impact-toughness of the alloys.Hence,the mechanical prosperities of ZA105 high zinc magnesium alloy are significantly improved with appropriate Sb addition,which provides a new way to extend the application fields of high zinc magnesium alloy.
基金Project(CXZZBS2019126)supported by the Innovative Support Program for Doctoral Students in Hebei Province,ChinaProject(QN2019078)supported by the Science and Technology Research Project of Colleges and University in Hebei Province,ChinaProject(51774137)supported by the National Natural Science Foundation of China。
文摘In view of the mechanics characteristic of cemented tailings backfill(CTB)at early age,the separation Hopkinson pressure bar test device was used to explore the effects of curing age and impact energy.A total of 48 CTB samples with diameter of 50 mm and length of 25 mm were prepared with curing ages of 3,5,7 and 9 d.Impact tests under different impact energy(10,20,30 and 40 J)were carried out.The microstructure of CTB at different ages was analyzed by scanning electron microscopy(SEM).The results show that,the curing age mainly affects the mechanical properties and internal structure of early-age CTB.With increasing curing age,the mechanical properties of early-age CTB change from viscoelasticity to brittleness.The impact energy mainly affects the response of dynamic peak compressive strength to strain rate.Under low strain rate,the structure of CTB is broken,but still has bearing capacity,affecting the formation of later strength.It is concluded that the structural loses completely under the action of high strain rate.Therefore,the control of impact energy and the protection of curing age should be fully considered in actual production process.
文摘Reference to the domestic and foreign relevant technical data, the paper design and manufacture enamel materials with a temperature resistant shock resistance and acid resistance excellent chemical stability, research on microscopic morphology of the enamel surface by scanning electron microscope, the experiment results showed： mill addition certain amount of zirconium silicate crystal in enamel material, enable enamel material to form composite materials of amorphous material and zirconium silicate crystals, it can effectively improve its temperature shock property; it is necessary to improve the enamel material temperature resistance shock property, but also maintain its excellent acid resistance, there is a optimal weight range mill addition into zirconium silicate crystal.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(Grant No.11625210)the National Science Foundation of China(Grant No.51873153)+1 种基金the Shanghai Pujiang Program(Grant No.19PJ1410000)the Shanghai International Science and Technology Cooperation Fund Project(Grant No.19520713000).
文摘In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layers configuration on the impact resistance is investigated by low-velocity impact test,and the impact failure mechanism of the 3D printed composites is explored by microscopic observations and finite element(FE)simulation analysis.The results show that the 3D printed multi-layered composite with SCF layers distributed in the middle(HFA)exhibits higher impact resistant performance than the specimens with alternating SCF/CCF layers(HFB)and CCF layers distributed in the middle(HFC).The effect of CCF/SCF layers proportion on the impact performance is also studied by FE simulation,and the results show that the specimen with a CCF/SCF proportion of 7.0 exhibits the highest impact strength.
