氮气流量及后续热处理对多弧离子镀制备Ti2AlN涂层的影响规律

EFFECTS OF NITROGEN FLOW RATE AND POST-HEAT TREATMENT ON PREPARATION OF Ti_2AlN COATINGS BY AIP

利用电弧离子镀技术在1Cr18Ni9Ti基材上低温沉积Ti-Al-N涂层,研究氮气流量及热处理工艺对涂层微观组织结构的影响。结果表明,沉积态涂层中不含三元层状陶瓷Ti_2AlN MAX相,可能含有Ti_3AlN(反钙钛矿结构)、TiN、α-Ti、fcc-Al及Ti_xAl_y金属间化合物等。涂层经退火后在一定条件下可以形成Ti_2AlN。涂层中的N元素含量及退火温度对Ti_2AlN的形成起到重要作用。N元素含量过多不利于Ti_2AlN的形成;提高退火温度可以促进Ti_2AlN的形成。透射电镜(TEM)分析结果表明,退火过程中Ti_2AlN的形成伴随着涂层微观组织结构的转变,从明显的层状结构转变为细小的等轴晶结构。

In the present work,Ti-Al-N coatings were deposited on 1Cr18Ni9Ti substrates at a low synthesis temperature using arc ion plating（AIP）.The effects of nitrogen flow rate and post-heat treatment on the microstructure of the coatings were investigated.The results show that no Ti_2AlN phase forms in all the asdeposited coatings.The coatings are possibly composed of Ti_3AIN inverse perovskite phase,TiN,α-Ti,fcc-Al and Ti_xAl_y intermetallic phase.Ti_2AlN phase can be detected in the annealed coatings in a given condition.It has been found that the nitrogen concentration in the coatings and the annealing temperature play a key role in the phase formation.The formation of Ti_2AlN phase is suppressed by the increment of nitrogen concentration and promoted by the enhancement of annealing temperature.TEM results indicate that the formation of Ti_2AlN phase is accompanied by the microstructure evolution from strong layered structure to fine equiaxed crystals in the process of heat treatment.