LEAD-FREE PIEZOCERAMIC MATERIAL COMPRISING A PEROVSKITE PHASE AND TUNGSTEN BRONZE PHASE AND METHOD FOR PRODUCING A PIEZOCERAMIC COMPONENT WITH THE MATERIAL

摘要

The invention relates to a lead-free, multi-phase piezoceramic material, comprising at least one perovskite phase having the perovskite phase composition (Li_xK_1-x-yNa_y) (Nb_1-t-uTa_tSb_u) O₃ and at least one tungsten bronze phase having the tungsten bronze phase composition (M^III_m(Li_xK_1-x-yNa_y)1_-m(Nb_1-wTa_w) ₅O₁₅ + VA'_2m, where M^III is at least one trivalent metal, VA' are a-site vacancies and the following relationships apply: 0 m ≤ 0.05; 0 ≤ t ≤ 0.15; 0 ≤ u ≤ 0.15; 0 ≤ w ≤ 1; 0 ≤ x ≤ 0.15; 0.25 ≤ y ≤ 0.75. Also disclosed is a method for producing a piezoceramic component using the piezoceramic material, said method comprising the following steps: a) a green body having a starting piezoceramic composition of the piezoceramic material is provided, and b) said green body is subjected to a thermal treatment, wherein the piezoceramic material of the component is produced from the starting piezoceramic composition. The piezoceramic component is, for example, an ultrasonic transducer or a piezoceramic bending transducer. In particular, the piezoceramic component is a multilayer piezo actuator used for actuating a fuel valve of an internal combustion engine of a motor vehicle.