Material mixing method for improving coating uniformity of bismuth-rich grain boundary phase of zinc oxide piezoresistor

The invention discloses a mixed material preparation method for improving distribution uniformity of a bismuth-rich grain boundary phase of a zinc oxide piezoresistor. The preparation method comprises the following steps: (1) weighing zinc oxide, bismuth nitrate pentahydrate, other metal oxide powder and a glycerin solvent for dissolving bismuth nitrate pentahydrate according to a ratio; nitrate of bismuth oxide is used as a key material, a solution for dissolving bismuth nitrate pentahydrate is mixed with zinc oxide and other metal oxide powder according to a specific proportion, then the mixture is treated through a ball milling technology, the agglomerated powder is dispersed, and the mixing uniformity of the raw materials is improved; the coating effect of bismuth oxide nitrate on zinc oxide powder particles is improved, the distribution uniformity of a bismuth-rich grain boundary phase of a sample is further improved, the electrical property and stability of the product are further improved, the energy c