目的 比较TiN和TiAlN涂层刀具加工铝锂合金的切削性能和表面质量。方法 使用硬质合金、TiN涂层和TiAlN涂层三种刀具，对2198-T8型铝锂合金进行干式铣削试验。改变切削因素的水平，比较刀具磨损、铝锂合金的表面粗糙度、切削力和切屑形态。结果 铣削铝锂合金时，刀具主要磨损为粘附磨损，TiN涂层的粘附程度最低，硬质合金次之，TiAlN涂层表面粘附最严重，切削效能最低。粘附磨损严重影响铣削成形的表面粗糙度，并使铣削力增加。铣削速度是影响工件表面粗糙度的主要因素，通过提高铣削速度可明显降低材料的粘结程度，降低表面粗糙度与铣削力，TiN涂层在铣削铝锂合金时最小表面粗糙度可达到0.5 μm以下。在相同的切削参数下，TiN涂层断屑均匀，切屑表面较为光滑，切屑塑性变形最小。硬质合金刀具产生的切屑尺寸较短，切屑表面有少量带状条纹，TiAlN涂层刀具产生的切屑发生了严重的塑性变形。结论 与TiAlN涂层和硬质合金刀具相比，TiN涂层刀具在铣削铝锂合金时的切削效能最好，可以达到最好的表面粗糙度和加工效果。

Carbide, TiN coating and TiAlN coating three tools were carried out for dry milling test of 2198-T8 aluminum lithium alloy, the machining surface quality and milling force data were obtained under different parameters and coating tool, chip characteristics was also observed and analyzed. The results show that when milling aluminum-lithium alloys, the main wear of the tool for adhesion wear, TiN coating adhesion degree is the lowest, followed by carbide, while surface adhesion of TiAlN coating tool is the most serious, the lowest cutting efficiency. The adhesion wear seriously affects the surface roughness of the milling forming, and increases the milling force; milling speed is the main factor affecting the surface roughness, by increasing the milling speed can reduce the degree of material adhesion, reduce the surface roughness and milling force, TiN coating in milling aluminum lithium alloy when the minimum surface roughness can reach 0.5 μm below. Under the same cutting parameters, the TiN coating chip breaks evenly, the chip surface is relatively smooth, and the chip plastic deformation is minimal; the chip produced by carbide tools has a short chip size, and there are a few stripes chip on the surface, and the chip produced by TiAlN coating tools undergoes serious plastic deformation. Compared with TiAlN coated tools, TiN coated tools have the best cutting efficiency and can achieve the best surface roughness and machining effect.