Dispersion and rheology for direct writing lead‐based piezoelectric ceramic pastes with anisotropic template particles

Abstract

Controlling the rheology of direct writing pastes is essential for producing high quality printed ceramics. Ceramic pastes were formulated to explore the relation between surface chemistry and rheology of complex pastes of Pb(In1/2Nb1/2)O3‐Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PIN‐PMN‐PT) powder, large BaTiO3 (BT) platelet particles, and a commercial poly(acrylic) acid‐based binder system. Zeta potential of the ceramic powder, the conformation of the poly(acrylic) acid, and the effect of these factors on rheology were evaluated as a function of suspension pH. Effective dispersion and amenable rheology for direct writing were achieved at mixing pH 5. Additions of 0.3 to 2.6 vol% BT tabular particles dramatically altered the rheology of the pastes due to the shear alignment of the BT particles. Powder‐organic interactions and the size and concentration of BT platelet particles can be tailored to direct write either space‐filling filaments to form dense ceramics or non‐flowing filaments to form spanning ceramic structures.

Robocasting of advanced ceramics: ink optimization and protocol to predict the printing parameters - A review

“…Similarly, coagulants are special polymers acting as glues to provide resistance to the external forces and enhance the viscoelastic response [13]. and c) images are adapted with permission from [79,83] and [80] respectively.…”

“…Finer powders are preferred for ink formulation as they allow better dispersion and sinterability, while large size particles have better flowability but are more prone to sediment. In fact, at a constant particle volume fraction, a narrow particle size distribution tends to increase the total surface area of the suspended particles by favouring a short interparticle distance which promotes strong particleparticle interactions [82,83]. The formation of a typical chains and networks of touching particles with strong interactions lead to an increase in the viscosity and yield stress of the suspension [75,84,85].…”

“…The influence of particle size and content of BaTiO 3 platelet pastes containing lead-based perovskites has been the scope of a detailed work performed by Walton et al [83]. As presented by the amplitude sweep curve in Figure 5b the particle size has been grouped into small-sized platelets in the range of 5-20 μm and large-sized platelets in the range of 20-40 μm.…”

4D Printing of Lead Zirconate Titanate Piezoelectric Composites Transducer Based on Direct Ink Writing

“…Trisodium citrate was added as a dispersant into ethanol to prepare a premixed solution. The surfaces of the particles were quickly wetted by dispersants, which increased the energy barrier between the particles in order to eliminate the agglomeration (Walton et al, 2020). After ball milling, the mixture was filtered and dried.…”

Direct ink writing of bismuth molybdate microwave dielectric ceramics

“…Multi-modal particle distributions; as the powder that is used, are often preferred when making ceramic formulations for additive manufacturing, since the combination of big and small particles within the suspension, often exhibit a more desirable rheological behaviour such as high solid content and lower viscosity [30,31] and reduced shrinkage during drying [32], compared to unimodal distributions. Additionally, this has been found to have a positive effect with sintering, as the smaller particles are expected to fill in any intra-granular gaps formed in between the larger grains and lead to improved packing densification and mechanical properties [32][33][34][35].…”