针对激光粉末床熔融(LPBF)传统合金三周期极小曲面(TPMS)点阵结构强塑性难以协同的难题,系统研究了Al Co Cr Fe Ni_(2.1)共晶高熵合金LPBF工艺及其TPMS点阵结构的力学性能。最优参数组合时Al Co Cr Fe Ni_(2.1)共晶高熵合金弹性模量达25...针对激光粉末床熔融(LPBF)传统合金三周期极小曲面(TPMS)点阵结构强塑性难以协同的难题,系统研究了Al Co Cr Fe Ni_(2.1)共晶高熵合金LPBF工艺及其TPMS点阵结构的力学性能。最优参数组合时Al Co Cr Fe Ni_(2.1)共晶高熵合金弹性模量达255 GPa,压缩屈服应力达1348 MPa,抗压强度达2520 MPa,压缩应变超25%。微观组织表征结果表明,其具有FCC(130~250 nm)/BCC(20~30 nm)双相纳米片层结构,元素偏聚形成异质界面协同强化。通过制造Diamond、Gyroid、Primitive三种TPMS结构及BCC桁架结构,揭示了点阵构型、相对密度和单胞尺寸结构参数对准静态压缩性能的影响规律。弹性模量、屈服应力及吸能均与相对密度正相关,Diamond、Gyroid和Primitive结构最大吸能分别达2369 J、2062 J和1096J。弹性模量与屈服应力随单胞尺寸增大呈线性增长,平台应力和吸能同步提升。Gyroid、Primitive结构在40%相对密度时比弹性模量的峰值分别达到47.8 GPa/kg、46.9 GPa/kg。相对Gyroid、Primitive、BCC构型,Diamond结构综合性能最优,比弹性模量达到72.6 GPa/kg,比吸能达38.7 J/g。与316L不锈钢和Ti-6Al-4V钛合金同类TPMS点阵综合对比,可知Al Co Cr Fe Ni_(2.1)点阵结构具有更为优异的强度-塑性匹配性能,在极端载荷条件下的高承载与吸能方面具有良好的应用前景。展开更多
Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted dru...Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.展开更多
In exploring hypersonic propulsion,precooler combined engines require the development of lightweight,efficient,and compact heat exchangers(HX).As additive manufacturing technology continues to progress,triply periodic...In exploring hypersonic propulsion,precooler combined engines require the development of lightweight,efficient,and compact heat exchangers(HX).As additive manufacturing technology continues to progress,triply periodic minimal surface(TPMS)structures,characterized by exceptionally high surface area to volume ratios and intricate geometric structures,have demonstrated superior heat transfer performance.This research examines the thermal-hydraulic(TH)behavior of FKS and Diamond as heat transfer structures under different Reynolds numbers through numerical simulations.The Nusselt number for FKS is 13.2%–17.6%higher than Diamond,while the friction factor for FKS is approximately 18.8%–29.3%higher.A detailed analysis of the internal flow mechanisms reveals that the flow pattern within TPMS can be summarized as cyclic convergence-separation-convergence.The fluid experiences constant disturbances from the structure in all spatial directions,generating strong turbulent mixing and large wall shear stresses,which significantly enhance heat transfer performance.展开更多
文摘针对激光粉末床熔融(LPBF)传统合金三周期极小曲面(TPMS)点阵结构强塑性难以协同的难题,系统研究了Al Co Cr Fe Ni_(2.1)共晶高熵合金LPBF工艺及其TPMS点阵结构的力学性能。最优参数组合时Al Co Cr Fe Ni_(2.1)共晶高熵合金弹性模量达255 GPa,压缩屈服应力达1348 MPa,抗压强度达2520 MPa,压缩应变超25%。微观组织表征结果表明,其具有FCC(130~250 nm)/BCC(20~30 nm)双相纳米片层结构,元素偏聚形成异质界面协同强化。通过制造Diamond、Gyroid、Primitive三种TPMS结构及BCC桁架结构,揭示了点阵构型、相对密度和单胞尺寸结构参数对准静态压缩性能的影响规律。弹性模量、屈服应力及吸能均与相对密度正相关,Diamond、Gyroid和Primitive结构最大吸能分别达2369 J、2062 J和1096J。弹性模量与屈服应力随单胞尺寸增大呈线性增长,平台应力和吸能同步提升。Gyroid、Primitive结构在40%相对密度时比弹性模量的峰值分别达到47.8 GPa/kg、46.9 GPa/kg。相对Gyroid、Primitive、BCC构型,Diamond结构综合性能最优,比弹性模量达到72.6 GPa/kg,比吸能达38.7 J/g。与316L不锈钢和Ti-6Al-4V钛合金同类TPMS点阵综合对比,可知Al Co Cr Fe Ni_(2.1)点阵结构具有更为优异的强度-塑性匹配性能,在极端载荷条件下的高承载与吸能方面具有良好的应用前景。
文摘Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.
基金supported by the Natural Science Basic Research Program of Shaanxi(Program No.2024JC-YBMS-449)Project ZR2022QE233 supported by Shandong Provincial Natural Science Foundation.
文摘In exploring hypersonic propulsion,precooler combined engines require the development of lightweight,efficient,and compact heat exchangers(HX).As additive manufacturing technology continues to progress,triply periodic minimal surface(TPMS)structures,characterized by exceptionally high surface area to volume ratios and intricate geometric structures,have demonstrated superior heat transfer performance.This research examines the thermal-hydraulic(TH)behavior of FKS and Diamond as heat transfer structures under different Reynolds numbers through numerical simulations.The Nusselt number for FKS is 13.2%–17.6%higher than Diamond,while the friction factor for FKS is approximately 18.8%–29.3%higher.A detailed analysis of the internal flow mechanisms reveals that the flow pattern within TPMS can be summarized as cyclic convergence-separation-convergence.The fluid experiences constant disturbances from the structure in all spatial directions,generating strong turbulent mixing and large wall shear stresses,which significantly enhance heat transfer performance.
