Mechanical Strength Enhancement of Lead Zirconate Titanate Ceramics Through Silicon Carbide Nanopowder Thermal Treatments
Dr. Chad Watson
Sandia National Laboratories (SNL) manufactures lead zirconate titanate (PZT) ceramics for use in applications that take advantage of their unique electrical properties. Due to the low fracture toughness and failure strength of PZT ceramics, crack initiation and propagation during component fabrication (grinding and poling), storage, and acceptance testing can result in premature product failure. Recent research suggests that the mechanical properties of PZT can be enhanced by an exposure to a silicon carbide (SiC) nanopowder thermal treatment, potentially increasing production yield and decreasing production costs. In an effort to establish a SiC nanopowder thermal treatment/mechanical property enhancement relationship for PZT manufactured by SNL, bend bars with dimensions of 3 x 4 x 45 mm were thermally treated with SiC nanopowder at temperatures ranging from 650°C to 900°C for 2 hour intervals. The flexure strength and hardness of the treated PZT bend bars will be evaluated and compared to those of untreated PZT. To begin developing an understanding of the potential strengthening mechanisms, diffusion depths of SiC into the PZT microstructure will be characterized using optical microscopy and scanning electron microscopy. Ultimately, enhancing the mechanical reliability of PZT ceramics would provide SNL with a method to increase production yield, thus reducing production costs.