铣刀倒棱角对大进给铣削718H模具钢影响研究

Influence of Milling Cutter Chamfering Angle on 718H Die Steel with High Feed Milling

采用5种倒棱角的大进给铣刀对718H模具钢进行铣削试验,分析了切削力、切屑表面形貌、表面粗糙度和刀具磨损等因素对刀片切削性能的影响。结果表明:随着倒棱角的增大,三向切削力Fx,Fy,Fz呈单调递增;切屑自由面和接触面都有明显的材料挤压,随着倒棱角的增大,其切屑挤压程度加剧,工件表面粗糙度增大;刀具的磨损形态主要为崩刃,并产生粘结磨损、涂层剥落和裂纹等损伤。刀具寿命先增大后减小,在倒棱角度为20°时,刀具寿命最长,为88min。在倒棱角度为20°时,刀具的切削性能提高,刀具磨损显著减少,从而极大地提高刀具耐用度。

Angle cutters,the cutting forces,chip surface topography,surface roughness and tool wear are analyzed by the high feed milling test of 718H die steel with five different chamfer.The results show that with the increase of chamfer angle,the cutting force Fx,Fy and Fz are monotonically increased.Both the free surface and contact surface of chip have obvious material extrusion.The degree of extrusion on the chip surface is increased with the increase of chamfer angle,the mechanism of tool wear is chipping,the wear of adhesion,disbanding and cracking are caused.However,the tool life is increased firstly and then decreased with the increasing chamfer angles,the tool life is increased to a maximum value about 88 min for cutting edge with 20°chamfer angle.In the high feed milling 718H steel experiments,the results show that there is an optimisted chamfer angle around 20°,where the tool will have the best cutting performance,and the tool wear can be effectively reduced,thus the tool life is greatly improved.