基于原子沉积法的纳米Al2O3涂层微织构刀具刀-屑界面间摩擦系数研究

Study on friction coefficient of tool-chip interface of nano-Al2O3 coating layer micro-texture tool based on atomic layer deposition

采用原子沉积法(Atomic Layer Deposition,ALD)分别在点状微织构和条状微织构YT5硬质合金刀具(微织构刀具)上制备了纳米Al 2O 3涂层,通过直角切削实验研究了纳米Al 2O 3涂层对微织构刀具刀-屑界面间摩擦系数的影响,并将纳米Al 2O 3涂层微织构刀具与微织构刀具、YT5硬质合金刀具进行对比。结果表明,微织构能降低刀具刀-屑界面间的摩擦系数;纳米Al 2O 3涂层能进一步降低微织构刀具刀-屑界面间的摩擦系数,其中厚度为100 nm的Al 2O 3涂层微织构刀具刀-屑界面间的摩擦系数最小,当点状微织构间距为0.15 mm时摩擦系数值最优,当条状微织构方向垂直于主切削刃时摩擦系数值最优;刀具刀-屑界面间的摩擦系数随着切削速度的增加而增大。纳米Al 2O 3涂层与微织构相结合将刀-屑界面间的摩擦由滑动摩擦转变为滑动-滚动复合摩擦的形式,降低了微织构刀具刀-屑界面间的摩擦系数,改善了摩擦性能,有利于提高刀具耐用度。

Atomic Layer Deposition(ALD)was used to prepare nano-Al 2O 3 coating on dot-like micro-texture and strip-like micro-texture YT5 cemented carbide tool(micro-texture tool).The effect of nano-Al 2O 3 coating on the friction coefficient of micro-texture tool-chip interface was studied by orthogonal cutting test.And compared nano-Al 2O 3 coating micro-texture tool with micro-texture tool and YT5 cemented carbide tool.The results show that micro-texture can reduce the coefficient of friction between the tool and chip interface.In addition,nano-Al 2O 3 coating can further reduce the friction coefficient of the micro-texture tool tool-chip interface.Among them,the coefficient of friction at the tool-chip interface of Al 2O 3 coated micro-texture tool with a thickness of 100 nm is the smallest.At the same time,when the dot micro-texture spacing is 0.15 mm,the friction coefficient is optimal,and the friction coefficient is the smallest when the direction of the strip micro-texture is perpendicular to the main cutting edge.In addition,the friction coefficient between the tool-chip interface of tool increases with the increase of cutting speed.The combination of nano-Al 2O 3 coating and micro-texture changes the friction of tool-chip interface from sliding friction to sliding-rolling composite friction,thus it reduces the friction coefficient between the tool-chip interface of micro-texture tool,and is beneficial to improve the tool durability.