Experimental Research On 3mm-diameter Hole Peck Drilling On High Volume Fraction SiCp/Al Composite

SiC particle reinforced aluminum matrix composites(SiCp/Al)are widely used in the aerospace,electronics and other fields.It have low density,high specific strength and stiffness,low thermal expansion coefficient and some other excellent physical and thermal properties.High hardness and wear resistance of this material makes its machining performance poor,easily lead to tool wear and surface quality defects.On the other hand,researches for drilling Si Cp/Al composites are very rare,greatly limits application of this material.Therefore,in order to further study the mechanism of drilling SiCp/Al composites,promote the application of high-level manufacturing,this reseach aims at high volume fraction(65%)of SiCp/Al composites,and design the drill basing on small diameter(Φ3mm)drill experimental study,the tool wear,drilled holes quality and other aspects.The main contents are as follows:(1)Learn the removal mechanism of SiCp/Al composites,and use parametric design method for tool structure design.From the analysis of the characteristics of the material itself SiCp/Al composites machining removal mechanism.Bonding material characteristics and mechanical removal of ways to structure and materials mainly discuss the design elements of the tool,lastly use UGNX secondary development program complete the drilling tool parametric design work.(2)Do the cutting force and torque test on the SiCp/Al composites,research the variation rules between different drills of the axial force of the drill bit when drilling.Experimental results show that diamond drill axial force far below the carbide cutting tools,PCD drill since the chisel too long will cause excessive torque.Wet cutting method can not reduce the axial force and torque.(3)Learn the tool wear conditions on drilling SiCp / Al composites by using three drill bits of different material,make a conclusion of cutting mechanism and tool wear law.PCD drill chisel edge is particularly serious,drilling bit blade wear form of a coating for local micro-hop edge and the flank carbide drills were milled horn small facets of 0 °.According to the change of flank wear with tool wear curve,obtained to verify the three stages of tool wear.(4)Analysis the drilled holes surface quality after drilling SiCp/Al composites,study the formation mechanism of surface defects.It explains the defects formation mechanism on entrance area,smooth cutting and outlet sections of the hole surface.