Single-side ground alumina piezo ceramic substrate(2)

When the piezo ceramic tile is positioned by the ceramic ring, the surface material of the alumina piezo ceramic after single-side grinding decreases with the decreasing of the hardness of the grinding disk, while the copper abrasive disk obtains the lowest surface roughness Ra.The quality of the grinding disc is second, and the cast iron grinding disc is the highest. The reason can be considered,when is using cast iron grinding disc for processing, the diamond abrasive particles will be embedded in the cast iron grinding disc during the processing. Due to the high hardness of the piezoelectric ceramic material, the binding effect on the abrasive particles is poor, so that the abrasive particles can be maintained. 

The three-body friction state is processed to obtain a higher surface roughness value; while the non-cast iron grinding disc is used for processing, the hardness of the abrasive grains is better because of its smaller hardness, and the diamond abrasive grains are ground in the non-cast iron. There is less tri-body friction on the piezo disc, which results in lower material removal rates and less damage to the workpiece. Although the hardness of the aluminum piezo disc is lower than that of the synthetic copper grinding disc, the low toughness of the aluminum piezo material causes the abrasive particles to "embed and disengage", on the one hand, the surface of the aluminum piezo ceramic is destroyed, and on the other hand, the surface of the aluminum piezo disc .The topography is mapped onto the surface of the workpiece, so that the surface uniformity of the workpiece is worse than that of the copper abrasive disc, and the surface roughness Ra is also increased accordingly. Therefore, the processing environment that eliminates the iron pollution source can solve the problem of yellowing of the surface of the alumina piezo ceramic substrate, and the copper grinding disc and the ceramic trimming ring are processed together for the best grinding effect.

The phenomenon of yellowing of the surface of piezoelectric transducers piezo rings substrate after grinding was analyzed. Combined with the characteristics of the piezo material in the grinding process, the root cause of the yellowing of the surface of alumina piezo ceramic substrate was analyzed. Three solutions were proposed through process test and detection. The scheme (the way in which the rust inhibitor is added to the polishing solution, the way is to improve the material removal rate, the method of using the iron-free grinding disc and the trimming ring) is verified, and the mechanism of action is analyzed and the following conclusions are drawn by oxidation.The reason why the surface color of the aluminum piezo ceramic substrate turns yellow is that the abrasive grains are slightly broken during the grinding process, so that the iron is separated from the cast iron plate and escaped into the polishing liquid in the dispersed state, and the iron is in a certain medium condition (water, The air, etc., undergoes a chemical action, and the product is yellowish and covers the surface of the alumina piezo ceramic substrate, which causes the surface of the alumina ceramic substrate to have a yellowish color after grinding.

The use of the rust preventive agent can solve the problem that the surface of the piezo ceramic transducer substrate becomes yellowish. The rust inhibitor can block the anodic process of dissolving iron metal and inhibit its chemical action. On the other hand, the rust inhibitor can also dissolve and peel off the material covering the surface of the alumina piezo ceramic substrate. And it escapes the surface of the piezo ceramic substrate.When the mechanical process of the abrasive particles during the grinding process is simultaneously carried out with the chemical reaction in the cast iron plate, the higher rate of mechanical removal can effectively remove the iron chemistry and cover the surface of the alumina piezo ceramic. But can not inhibit the chemical action of iron. When the single-side grinding (high mechanical removal rate) is performed by using the diamond abrasive and the cast iron grinding disc, and the polished sheet can be effectively cleaned and removed after processing, the problem of yellowing surface of the alumina piezoelectric ceramics ring substrate after grinding can be solved. Under the condition of grinding of non-cast iron grinding disc and ceramic ring, the alumina piezo ceramic substrate can obtain the processing environment without iron participation, which can solve the problem that the color of the alumina piezo ceramic substrate is yellow after grinding. Among them, the copper grinding disc is used together with the piezo ceramic ring for the best grinding effect, but it is more suitable for the fine grinding of small particle size for fine grinding, while the cast iron grinding disc is more suitable for abrasive with large particle coarse grinding.