Lead-free piezoelectric ceramic sensor material and a preparation method thereof

A preparation method of a lead-free piezoelectric ceramic sensor material, comprising following steps:

• preparing ingredients:
• weighing and taking a required mass of main raw materials according to mass percentages of each main raw material, wherein the main raw materials include barium carbonate, calcium carbonate, zirconia, titanium dioxide, strontium carbonate, erbium oxide and bismuth oxide, and mixing the main raw materials uniformly to prepare a mixed raw materials, wherein the mass percentages of the main raw materials include 32.8-35.3% of the barium carbonate, 34.4-38.7% of the calcium carbonate, 8.5-10.3% of the zirconia, 8.6-11.0% of the titanium dioxide, 3.8-5.2% of the strontium carbonate, 2.4-3.7% of the erbium oxide, and 1.5-4.2% of the bismuth oxide;
• ball milling:
• adding the mixed raw materials into a high-energy ball mill, then adding a dispersant agent in a mass of ⅓ of 0.3-0.6% of the dispersant agent of a total amount of the main raw materials and a deionized water, starting a wet ball milling, and a mass ratio of the mixed raw materials and the deionized water is 1:1, a ball milling rate is 320-380 r/min, preforming the wet ball milling for 4-5 h;
• then continuing to adding lithium oxide in a mass of 0.21-0.35% of the total amount of the main raw materials, a mass of yttrium oxide in a mass of 0.18-0.29% of the total amount of the main raw materials and a mass of ⅔ of 0.3-0.6% of the dispersant agent of the total amount of the main raw materials into the high-energy ball mill, starting a secondary ball milling and the ball milling rate is 320-380 r/min, and preforming the secondary ball milling for 10 h;
• granulating and tableting:
• suction filtering a slurry after ball milling, and then processing the slurry after ball milling into a 400 mesh granular ceramic powder through a centrifugal spray dryer;
• uniformly mixing the 400 mesh granular ceramic powder with absolute ethyl alcohol in a mass ratio of 1:0.3, adding a composite binder in a mass of 3.5-4.5% of the total amount of the main raw materials, and after mixing uniformly, heating up to 70° C., stirring for 1 h, and then granulating into pellets;
• and placing the pellets in a stainless steel mold and pressing the pellets into a green body with a required thickness under a pressure of 12-18 MPa;
• debinding:
• putting the green body in a heating furnace, heating up to 200-250° C. for 60 minutes;
• and then heating up to 500-600° C. at a rate of 3-5° C/min for 2 h;
• then heating up to 720-780° C. for 3 h;
• and
• sintering:
• putting a debinding green body in a clamp pot, covering tightly, and sintering at 1050-1180° C. for 3-4 h;
• and then naturally cooling the debinding green body to a room temperature, preparing the lead-free piezoelectric ceramic sensor material.