Wear Behavior of Ti(N,C)-Al<sub>2</sub>O<sub>3</sub> Coated Cemented Carbide Tools during Milling Ti<sub>2</sub>AlNb-Based Alloy

Ti2AlNb-based alloy is regarded as lightweight high-temperature structural material, which is expected to replace the nickel-base super alloy due to its low density, high elastic modulus, strength retention at elevated temperature, outstanding oxide resistance. However, these excellent properties also make Ti2AlNb to be difficult-to-cut material. In this paper, the milling experiment of Ti2AlNb alloy was carried out using Ti(N,C)-Al2O3 coated cemented carbide tools. SEM and EDS analysis was utilized to observe the worn tools to determine the tool failure modes and wear mechanisms. Tool life when milling Ti2AlNb was short and heavily dependent on the cutting parameters. During milling, coating material of the tool was separated rapidly from the base material. When the cutting speed exceeded 100m/min, serious cracks appeared on the tool surface. Thermal fatigue, adhesive and attrition were the predominant wear mechanisms of the coated tools.