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 ( L a ) and the size of large-scale cavities in the sintered structure ( L c ) 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 ( τ f ). A relationship τ f = τ c /(1 + √(2 L cmax / d )) is established, which fits the experimental results very well. The model reveals that the relative agglomerate size ( L a / d ) or relative cavity size ( L c / d ) plays a more important role than the particle size ( d ) itself in terms of defining the final sintering properties of metal nano/microparticles.