Research On Machining Characteristics Of Hard And Brittle Materials By Micromilling

Hard and brittle materials,such as glass and ceramic,due to its high hardness, high strength, thermostability,corrosion preventive and other characteristics, has been widely noticed and used in recent years. However, because of high hardness and brittleness and low fracture toughness, hard and brittle materials can easily produce brittle brake or other undesirable phenomenon in machining. With the development of micromachining technology, micromilling technology is widely used in various industries and also puts forward new requirement for micro machining of hard and brittle materials.In this paper, in order to research the processing characteristics of micro milling and processing mechanism of hard and brittle materials, micro ball milling cutter is used to complete plastic domain processing of hard and brittle materials. Combined with the different processing phenomenon of micro milling and conventional milling, hard and brittle materials micro milling mechanism is analyzed from the size effect and minimum cutting thickness phenomenon. Combined with micro ball milling cutter geometry model and the machining process instantaneous cutting thickness model and joined the influence of tool inclination angle, the linear force model of ploughing force and shearing force is established for the analysis of materials processing.In order to reduce the influence of micro milling cutter self deformation and tool vibration for experiment processing results and reduce brittle fracture during machining hard and brittle materials, this paper takes the cutter extended length as the variable conditions and analyze the mechanical characteristics of the micro milling cutter by ANSYS. Besides, analyzing the milling cutter stress distortion and mode is used to determine the best cutter extended length.In addition, this paper has conducted micro-milling experiment for glass on self-developed experiment platform and studied the micro milling experiment of hard and brittle materials by using orthogonal experimental method. The influence degree of each processing parameter on the experimental results and the influence of single factor processing parameters changing on experimental results trend are studied through the analysis of the experimental data. Besides, the milling force model is validated by the comparison of theoretical value and experimental milling force test data.