陶瓷刀具超高速铣削镍基高温合金刀具失效机理研究

Failure Mechanisms of a Ceramic Tool in Ultra-high Speed Milling of Nickel-based Super Alloys

采用sialon陶瓷刀具进行了超高速铣削镍基高温合金Inconel 718实验,应用线性回归及极差分析法,研究了在超高速切削范围内切削参数对切削力和切削温度的影响程度,揭示超高速切削刀具失效机理,探讨超高速加工的可行性。结果表明:切削速度、进给量、轴向切削深度对切削合力峰峰值影响依次减少,而对切削温度的影响按显著程度依次为轴向切削深度、进给量和切削速度。陶瓷刀具超高速失效机理主要是剥落、崩刃和粘结磨损,热应力和机械应力交互作用是刀具失效的主要原因。

A series of orthogonal ultra-high-speed milling Inconel 718 experiments were carried out with sialon ceramic tools. The effect of cutting parameters on the cutting forces and cutting temperature was investigated by linear regression method and range analysis method. The failure mechanisms of ultra-high-speed cutting tools were revealed to investigate the feasibility of the ultra-high-speed machining. The results show that the order of the impact on the average peak resultant cutting forces was cutting speed,feed rate and axial depth of cut,while the order of the impact on the cutting temperature was axial depth of cut,feed rate and cutting speed. The main failure mechanisms of the sialon ceramic tool at ultra-high-speeds were flaking,chipping and adhesive wear. The combined effect of thermal stress and mechanical stress was the main factor in the failure of the tool.