Preparation And Application Of Ultrasonic Assisted Face Grinding Discs

Hard and brittle materials are widely used in machinery manufacturing,aerospace,national defense,petrochemicals and other fields because of their good mechanical and physical properties.However,the high hardness and brittleness of hard and brittle materials make their machining very difficult.Ultrasonic-assisted grinding is considered as an effective method of precision machining of hard and brittle materials,but the current research is limited to smaller workpieces or tools.In order to solve the problem of low processing efficiency and poor surface quality which exist in the grinding process of hard and brittle sheet parts,a new method of large size ultrasonic-assisted face grinding disc is presented in this paper,and the ultrasonic-assisted face grinding disc is used for ultrasonic-assisted grinding of hard and brittle sheet parts.The main researches of this paper are as follows:(1)A large-size radial ultrasonic-assisted end grinding disc preparation method is proposed for large-size discs for grinding of hard and brittle sheet parts,and the overall structure of the ultrasonic-assisted end face grinding disc is formulated.(2)According to the overall structure of the ultrasonic-assisted end grinding disc,a single ultrasonic vibrating block is first designed and manufactured using software such as three-dimensional software Pro/ENGINEER and finite element ANSYS,and the vibration characteristics of the prepared single ultrasonic vibrating block are also studied.The test is conducted and the measured results show that the ultrasonic vibrating block has good vibration effect and can meet the design requirements.(3)The overall structure of the ultrasonic-assisted face grinding disc is designed,including the connection between the arrangement of the single ultrasonic vibrating block and the fixed chassis,and the connection between the fixed chassis and the spindle.The preparation and commissioning of the disc is carried out according to the results of the design.And test it.The test results show that the ultrasound-assisted end grinding disc meets the design requirements and can realize ultrasonic vibration with a frequency of about 20 KHz.(4)The redesign of some key mechanisms on the basis of existing common single-sided lapping machine tools mainly includes: design optimization of the box that supporting the integral parts and grinding fluid supply recovery system.The various parts that constitute the rotating system(Such as spindles,motors,etc.)are designed and calibrated.The design of the main body supporting the grinding of workpieces mainly consists of motors and components for workpiece loading.The electrical control part of the ultrasonic-assisted end grinding machine is designed.(5)Ultrasonic grinding can achieve higher material removal rate and better surface quality when grinding sapphire under different grinding pressure and different disc speed.The improvement degree of grinding effect on A-plane,C-plane,M-plane and R-plane of sapphire is different by ultrasonic grinding.The material removal rate of C-plane increases 25.3%,A-plane increases 26.99%,M-plane increases 23.49% and R-plane increases 52.56%.The surface roughness of C-plane decreases 5.36%,A –plane decreases 4.17%,M-plane decreases 2.82%,R-plane decreases 8.02%.(6)The ultrasonic-assisted grinding machine can be applied to the grinding of hard and brittle parts.It can not only improve the machining efficiency,but also improve the surface quality.