t‐ZrO2 toughened Al2O3 free‐standing films and as oxidation mitigating thin films on silicon nitride via colloidal processing of flame made nanopowders (NPs)

• DOI: 10.1111/jace.17570
• Publication Date: 2020-11-09T20:45:21Z
• Authors: Xinyu Zhang; Xiaopo Cheng; Monika Jansohn; Matthias Niedermaier; Thomas Lenk; Stefan Britting; Karsten Schmidt; Richard M. Laine
• Keywords: LF‐FSP; nitrides; nanopowders; Si3N4; alumina; 01 natural sciences; power electronic substrates; sinter/sintering; Engineering; Materials Science and Engineering; 0103 physical sciences; nanoparticles; ZTA; tetragonal zirconia; zirconia

Abstract Zirconia toughened aluminas (ZTAs) are one of the most important engineering ceramics with high melting points, excellent mechanical strength, and chemical stability, commonly used as wear resistant high‐temperature components, prosthetic implants, electric circuit substrates. In this work, we explore methods processing fine‐grained, dense, thin, free‐standing (ZrO 2 ) x (Al O 3 1− films ( = 0‐50 mol%, ~40 μm thick) by sintering flame made nanopowders (NPs) to optimize t ‐ZrO content, sinterability, microstructures under select conditions (1120°C‐1500°C/5 h in or 95%N /5%H ). all cases, final sintered products retain t‐ ZrO average grain sizes (AGSs) 0.1‐1 μm. ZTA film thicknesses were increased ~200 assess potential electronic Excellent fracture toughness (24 MPa m 1/2 small AGSs 0.7 found for thick at 1500°C/5 h/N /H using a three‐step binder burnout process. Furthermore, show that homogeneous thin (<5 can be on Si N 4 substrates (thickness ≈ 300 μm) provide physical protection against oxidation extreme (1500°C/1 h/O ), offering additional practical utility power