Influences of zirconium tungstate additives on characteristics of polyvinylidene fluoride (PVDF) components fabricated via material extrusion additive manufacturing process

Polyvinylidene fluoride (PVDF), a thermoplastic material with excellent resilience and piezoelectric potential, is a natural candidate for use in filament-based additive manufacturing technologies. However, due to the high thermal expansion and low surface energy of homopolymer PVDF, fabrication of this polymer via extrusion deposition processes is challenging, often resulting in substantial stress accumulation and unwanted distortion in printed parts. To address these challenges, this work investigates the effects of adding microscale zirconium tungstate particulate to improve the printability of PVDF materials. Zirconium tungstate was specifically selected because for its demonstrated negative coefficient of thermal expansion over the range of standard filament extrusion deposition method processing temperatures. Composite filament specimens were characterized with respect to mechanical, thermal, and microstructural properties. Compared with pure homopolymer printed specimens, results show that the particulate additives effectively lowered the net coefficient of thermal expansion at the expense of yield strength and total elongation to failure, while the semi-crystalline structure showed a mild reduction in β-phase formation associated with increasing particulate content.