N_2气流量比对磁控溅射Mo-N涂层结构和性能的影响

Effect of N_2 Flow Ratio on Structure and Property of Mo-N Coatings Deposited by Magnetron Sputtering

目的研究N_2气流量比对直流反应磁控溅射Mo-N涂层结构、力学性能和摩擦性能的影响。方法采用直流反应磁控溅射技术在304不锈钢基体表面制备Mo-N涂层,对涂层结构进行X射线衍射(XRD)分析,对涂层形貌和磨痕形貌进行扫描电镜(SEM)分析,采用维氏显微硬度计测试涂层的显微硬度,采用划痕法表征涂层的结合强度,采用球盘式摩擦磨损试验仪评价涂层的摩擦磨损性能。结果随着N_2气流量比R从0.3增加至0.7,涂层主要由面心立方γ-Mo2N相构成,当R为0.7时,制备的涂层中出现少量的六方δ-MoN相。涂层的显微硬度先降低后增加,最高硬度可达3060HV。结合强度先增加后降低,当R为0.4和0.5时,涂层的结合力较高,约为40N,且具有较好的摩擦学性能,平均摩擦系数约为0.22,磨损形式主要为磨粒磨损。结论在基体温度为300℃时制备涂层,N_2气流量比在0.3～0.7的范围变化对涂层相结构的影响较小。硬度相对较高时,结合力越好,摩擦学性能越好。

The work aims to study the effect of N2 flow ratio(R=N2/(Ar+N2))on structure and mechanical and tribological properties of molybdenum nitride(Mo-N)coatings by DC reactive magnetron sputtering.Mo-N coatings were deposited on 304 stainless steel substrates by DC reactive magnetron sputtering.The structure,surface morphology and wear morphology,microhardness,adhesion strength,friction and friction and wear properties of Mo-N coatings were analyzed,characterized and evaluated by SEM,XRD,Vicker microhardness meter,Rockwell indenter and ball-on-disk tribometer,respectively.With the increase of nitrogen flow ratio(R)from 0.3 to 0.7,the coating was mainly composed ofγ-Mo2N face-centered-cubic(fcc)phase.When R was 0.7,a small volume ofδ-MoN hexagonal phase appeared in the coating.The microhardness of the coating decreased first and then increased,and the maximum hardness reached 3060HV.The adhesion strength of the coating first increased and then decreased.When R was 0.4 and 0.5,the coatings exhibited higher adhesion strength(40 N)and better tribological properties.The average friction coefficient was about 0.22 and the coating wear was mainly abrasive wear.For the coating prepared on 300℃substrate temperature,N2 gas flow ratio(0.3~0.7)has a little effect on the phase structure of the coating when changing between 0.3~0.7.When the hardness is relatively high,the better adhesion strength is,the better tribological properties are.