Requirements for the transfer of lead-free piezoceramics into application

The recent review for the Restriction of Hazardous Substances Directive (RoHS) by the expert committee, appointed by the European Union, stated that the replacement of PZT " ... may be scientifically and technologically practical to a certain degree ... ", although replacement " ... is scientifically and technically still impractical in the majority of applications." Thus, two decades of sustained research and development may be approaching fruition, at first limited to a minority of applications. Therefore, it is of paramount importance to assess the viability of lead-free piezoceramics over a broad range of application-relevant properties. These are identified and discussed in turn: 1. Cost, 2. Reproducibility, 3. Mechanical and Thermal Properties, 4. Electrical Conductivity, and 5. Lifetime. It is suggested that the worldwide efforts into the development of lead-free piezoceramics now require a broader perspective to bring the work to the next stage of development by supporting implementation into real devices. Guidelines about pertinent research requirements into a wide range of secondary properties, measurement techniques, and salient literature are provided. (c) 2018 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.