Low-Temperature Fabrication of Refractory Thin Films via Electric Field and Contact Stress-Activated Sintering of Nanoparticles: An <i>In Situ</i> Study.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41247354.
- Also identified by DOI 10.1021/acs.nanolett.5c04675 and PMC identifier 12670486.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Refractory nanocomposite films are employed to prevent wear of mechanical components under harsh conditions; however, they are traditionally manufactured at elevated temperatures, causing undesirable microstructural transformations. This study presents a novel electric field- and contact stress-activated sintering process for fabricating tungsten carbide (WC-Co) films at low temperatures (100 °C). In this process, nanoparticle-containing "inks" are supplied to stressed sliding/rolling interfaces, while simultaneously applying direct current. Elevated stresses (>1 GPa) and electric currents (2-5 A) drive nanoparticle sintering on contacting surfaces, generating thin films within minutes. Here, we present the results of an <i>in situ</i> study of the kinetics of sintering using optical interferometry. The application of electric currents enhanced film thickness, reduced surface roughness, and increased the fraction of WC incorporated into the film. Co played a critical role in film nucleation by forming a deformable matrix for trapping hard WC nanoparticles. This manufacturing approach provides a rapid, low-temperature pathway for fabricating nanostructured films.