Approaching the structure-property relationship of sintered metal nano/microparticles from the perspective of the agglomerate size effect

In this study, we explore the structure-property relationship of sintered metal nano/microparticles from the perspective of the agglomerate size effect. Through sintering experiments and mechanical tests of Cu particle pastes with different solvents, a linear correlation between the agglomerate size in the particle paste (La) and the size of large-scale cavities in the sintered structure (Lc) is revealed, and a negative correlation between the cavity size and the shear strength of the sintered structure is discovered. Based on these results, a quantitative model is proposed to predict the overall strength of the sintered structure (τf). A relationship τf = τc/(1 + √(2Lcmax/d)) is established, which fits the experimental results very well. The model reveals that the relative agglomerate size (La/d) or relative cavity size (Lc/d) plays a more important role than the particle size (d) itself in terms of defining the final sintering properties of metal nano/microparticles.