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The glass/mold interaction is crucial for controlling the surface quality of high‐precision glass products and elongating the lifespan of precious molds in hot forming techniques. Here we employ the probe tack test to separate a typical glass molding interface composed of N‐BK7 glass and tungsten carbide molds at different temperatures from 655 to 690°C. The macroscale debonding behavior translates from interfacial fracture to cohesive bulk deformation as temperature increases. The glass surfaces after debonding are covered by numerous randomly distributed cavities in micrometer. With temperature increasing, the maximum depth of microcavities greatly increases from less than 0.5 to over 10 μm; the area fraction overall increases and reaches 15% at maximum. These microcavities could result from the development of localized deformation at the gas‐trapping spots, due to the separation of the adhesive glass/mold interface. A large‐sized cavity evolves from the cyclic growth and coalescence of small cavities. For the interfacial fracture cases, cavities mainly propagate as cracks along the interface, and thus develop into shallow disc‐like shapes. However, for the cohesive cases, cavities prefer to grow in the bulk. The growth bifurcation could be governed by the competition between strain energy release rate and viscoelastic complex modulus.

Comparisons Between 2D anD 3D mpFem simulations in moDeling uniaxial HigH VeloCityCompaCtion BeHaViors oF ti-6al-4V powDer Multi-particle finite element method (MPFeM) simulation has been proven an efficient approach to study the densification behaviors during powder compaction. however, comprehensive comparisons between 2D and 3D MPFeM models should be made, in order to clarify which dimensional model produces more accurate prediction on the densification behaviors. in this paper, uniaxial high velocity compaction experiments using Ti-6al-4V powder were performed under different impact energy per unit mass notated as E m . Both 2D and 3D MPFeM simulations on the powder compaction process were implemented under displacement control mode, in order to distinguish the differences. First, the experimental final green density of the compacts increased from 0.839 to 0.951 when E m was increased from 73.5 J/g to 171.5 J/g. Then detailed comparisons between two models were made with respect to the typical densification behaviors, such as the density-strain and density-pressure relations. it was revealed that densification of 2D MPFeM model could be relatively easier than 3D model for our case. Finally, validated by the experimental results, 3D MPFeM model generated more realistic predictions than 2D model, in terms of the final green density's dependence on both the true strain and E m . The reasons were briefly explained by the discrepancies in both the particles' degrees of freedom and the initial packing density.