Study On Performance Of Thermal Shock Resistance For Micro Textured Cemented Carbide Ball End Milling Cutter

In order to ensure the machining quality,the milling of titanium alloy usually adopts the high speed and small feed machining method,due to the small tool contact area and the poor thermal conductivity of titanium alloy,the surface temperature of the tool is too high,which aggravates the thermal shock phenomenon and affects the tool life and its cutting performance.Milling is a typical intermittent cutting,the tool cutting in and out accompanied by instantaneous high temperature heating instantaneous low temperature cooling,continuous cycle through the cooling-heating process,temperature changes make the internal and external surfaces of the tool constantly subject to alternating tensile-compressive stresses,this repeated impact in the tool to generate thermal stresses,in the front tool surface perpendicular to the cutting edge will produce a series of cracks.The thermal cracks will expand and grow with the milling process,leading to thermal shock fatigue failure of the tool.As one of the main forms of tool failure,thermal shock fatigue failure can cause a lot of economic loss and resource waste.In this paper,we analyze the thermal shock resistance of microweave carbide ball end milling tool based on milling titanium alloy,in order to obtain the influence law of microweave parameters on the thermal shock behavior of the tool,to achieve high quality machining of titanium alloy and improve the tool performance.Firstly,the design of the thermal shock test scheme of the microloom carbide tool material was carried out,with the residual flexural strength as the evaluation index;the experimental study of the thermal shock resistance of the tool material was carried out to analyze the influence law of the microloom parameters on the thermal shock resistance of the tool material,so as to lay the foundation for the subsequent simulation analysis of the microloom carbide ball-end milling tool and the milling temperature test.Secondly,based on the heat source method to analyze the heat source change of the tool in the milling process,construct the mathematical model of the heat source above the tool-work contact area;establish the micro-loom complete thermal coupling simulation model to conduct complete thermal coupling analysis of the dynamic temperature field of the tool;study the heat source change of the tool milling process and the temperature change range of the tool-work contact area.Again,the test platform of "turning instead of milling" is built,and the noncontact high-precision infrared thermometer is used to collect the milling temperature of the tool and obtain the peak and valley temperatures and their differences;the influence law of micro-weaving parameters on the change of milling temperature is studied;the indirect thermal coupling model is built to analyze the mechanism of the influence of micro-weaving parameters on the thermal stress of the tool.Finally,based on the experimental and simulation results data,the regression model of microloom parameters is established using stepwise regression method;the multi-objective optimization of microloom parameters is carried out based on particle swarm algorithm.