Common processing method of alumina piezo ceramic substrates

    Alumina acoustic piezoelectric tubes materials are difficult to process materials, with the high hardness, brittleness including grinding, cutting, laser heating, high pressure abrasive water processing and ultrasonic processing.

     Grinding: Alumina piezo ceramics have the high hardness, so grinding wheels are usually made by diamond material. In the grinding process, B4C is used as the abrasive for grinding. Studies have shown that the material removal methods of alumina piezo ceramics during grinding mainly includes grain removal, brittle fracture, material stripping,grain boundary and micro crushing. The voids and cracks on the surface of the high frequency piezoelectric ceramic are subjected to four stages of forming, stretching, peeling and cracking, so that the entire grain peeled off from the surface of the workpiece, and the brittle removal process of the material is completed. In the actual grinding process, the machine's characteristics, grinding parameters and grinding shape have an effect on the grinding process.

Machining: Considering the processing efficiency of the tool, the cutting process of alumina piezo ceramics is carried out by the gold.Rough stone or cubic boron nitride is used as the tool material. When PZT tube piezoelectric ceramic have fracture toughness of the material ,which the main factors are affecting the cutting force. Because of the high hardness, the cutting edge is difficult to cut in, so the radial force is much larger than other components by 5-10 times. Tools includes mechanical wear, chemical wear, and flaking due to grain boundary damage and cracking. High speed, depth of cut and large feed rate increases tool, and the radius of the tool can be increased to the tip strength and heat dissipation.

Laser processing: laser processing is laser-based non-contact processing of processing energy, thus avoiding brittleness material.Surface cracks are generated during sexual removal. When high-energy laser acts on the surface of the machined part, the thermal energy is converted by the light energy on the surface of the workpiece will cause a small temperature in the surface of the workpiece due to the high efficiency of the long-wavelength laser. Rapidly raises and melts  the workpiece material to achieve the effect of material from the surface of the piezoelectric ceramic products. Since the focused spot is small and the heat-affected area is small, precision processing of the alumina piezo ceramic can be achieved.

Ultrasonic machining: Ultrasonic machining essentially adds liquid or paste between the tool and the gap between the workpiece .The abrasive material is ultrasonically vibrated, so that the abrasive particles continuously have impact, press,polishing the surface of the material to be processed at a high speed, so that the material that is impacted and ground flows out, thereby achieving the purpose of cutting. piezoelectric ceramic effects are applied to the surface of the processing tool and the workpiece to be processed. There is a liquid or paste-like abrasive between the tool and the gap of the workpiece to be processed. It is necessary to apply a slight pressure to the processing tool to press the workpiece to be processed.