The interfacial microstructure of zirconia and MaCor™ joined using spin-on interlayers

Scanning and transmission electron microscopy (SEM and TEM) were used to investigate the interfacial microstructure of sintered polycrystalline partially stabilized zirconia (PSZ) specimens bonded to a commercial machinable glass ceramic (MaCor™). All specimens were joined using a thin (approximately 400 nm) amorphous silica interlayer. This interlayer was produced by spin coating an organic based silica bond material precursor and curing at 200°C, followed by joining in a single-mode microwave cavity. After joining, no evidence of the silica bond layer was observed, with the silica presumably dissolving into the surrounding materials. The bond interface was non-planar as a result of the strong wetting of MaCor™ and silica and dissolution of ZrO2. The interfacial microstructure shows intimate bonding between the zirconia and MaCor™, without any additional observed interfacial phases. This microstructural development is discussed.