摘要：The finite element analysis （FEA） software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom comer of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom comer. When non-uniform interference is adopted the first principal stress at the comer on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the comer stress concentration. The first principal stress at the comer of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.

摘要：due to their unique surface chemistry,highly adjustable metal components,hydrophilicity,and high carrier concentrations,MXenes are applied in a variety of *** to other two-dimensional(2d)materials,building heterostructures with additional materials to form a 3d porous architecture for MXenes can significantly enhance their functionality and ***,the open structures and well-defined pathways of these 3d structured MXenes can improve ionic and electronic transport,thereby promoting their applications in electrochemical energy storage,sensing,catalysis,and *** this review,the recent efforts made on preparing 3d porous MXenes with heterostructures,focusing on MXenes/C,MXenes/inorganics,and MXenes/polymers were *** discussion covers aspects ranging from the design to synthesis of 3d porous MXenes,and their applications in photocatalysis,environmental monitoring and electrochemical energy *** review is concluded by presenting the prospects and insights on exploring the relationships between the porosity formation mechanisms,properties and applications of the 3d porous MXenes *** review can provide meaningful guidance for the design,fabrication and application of 3d porous MXenes in high-performance materials and devices.