The Change Of Tool Performance During CFRP/Ti Hole Making And Its Effect On Tool Wear

Carbon fiber reinforced resin matrix composites(CFRP)and titanium alloy show excellent performance in mass and specific strength,which greatly reduce the structural weight of aircraft,and have a wide range of applications in the aerospace field.As a very important tool,the hardness of cemented carbide tool is affected by temperature and load.In this paper,the hardness changes of cemented carbide tools during drilling and the influence on tool wear during drilling of CFRP/Ti laminated components are studied:Firstly,in order to explore the law of hardness changes of cemented carbide materials at different temperatures and loads,Vickers indentation tests at different temperatures were designed,and the surface damage of the indentation was tested.The results showed that:under normal temperature conditions,the load increasing,the Vickers hardness of cemented carbide decreases.When the load is constant and the temperature increases,the Vickers hardness of the cemented carbide decreases,and a method to evaluate the degree of surface damage of the indentation is proposed.Secondly,in order to study the cutting force and cutting temperature when making holes in CFRP/Ti laminates,five different stacking methods of CFRP and titanium alloy were designed,and the temperature and cutting force during drilling of each stacking method were studied.The results show that when continuously drilling the interface between titanium alloy and titanium alloy,the cutting force and cutting temperature continue to increase.When the drill bit drills from the titanium alloy layer to the CFRP layer,the drilling temperature of CFRP increases significantly.Thirdly,in order to study the relationship between the hardness and tool wear of the tool under different cutting force and cutting temperature conditions,the tool wear during drilling with different lamination methods was tested.The results show that the cutting force has a significant impact on the hardness of the tool,and the decrease in hardness aggravates the wear of the tool.In addition,as the tool wears,the edge radius of the main cutting edge gradually increases.Finally,in view of the hole quality of the CFRP/Ti laminated component and the sub-surface damage of the CFRP layer when the tools with different wear conditions are drilled,the quality of the entrance and exit of the bottom CFRP of different laminated methods is tested.The damage of the sub-surface was observed,and the results showed that the precision of hole-making of severely worn tools decreased significantly and caused more damage to the sub-surface of the CFRP layer.