Preparation and sintering method of potassium-sodium niobate-based piezoelectric ceramic

The invention discloses a preparation and sintering method of potassium sodium niobate based piezoelectric ceramics. The preparation and sintering method comprises the following steps: preparing raw materials of K2CO3, Na2CO3, Nb2O5, CaCO3, ZrO2, Bi2O3, HfO2 and Li2CO3; carrying out primary ball milling on all the raw materials to obtain ceramic powder, and drying the ceramic powder; carrying out pre-sintering on the dried ceramic powder; carrying out secondary ball milling on the pre-sintered ceramic powder, and drying to obtain pre-sintered ceramic powder; putting the granulated ceramic pre-sintered powder into a graphite mold, and tabletting; the graphite mold is placed in an SPS sintering furnace to be pressurized, heated and formed, and a ceramic block is formed; cooling the graphite mold; the obtained ceramic block is annealed, a carbonized layer generated on the surface in the SPS sintering process is eliminated, and finally the high-density potassium-sodium niobate ceramic is obtained. The invention a