物理气相沉积CrN和AlCrN涂层转动微动摩擦磨损性能研究

发布时间：2018-03-05 10:15

本文选题：PVD　切入点：CrN涂层　出处：《西南交通大学》2011年硕士论文　论文类型：学位论文

【摘要】：物理气相沉积(简称PVD)技术制备的CrN涂层以及CrN加入Al后形成的三元Cr-Al-N系涂层具有优良的综合性能,已被成功用于刀具、模具、轴承和活塞环等耐磨零件表面,其中高A1含量的AlCrN涂层由于其优越的抗高温氧化和磨粒磨损性能更是成为新一代三元PVD氮化物涂层最典型的代表。转动微动磨损是在交变载荷下接触副发生转动的相对运动所造成的磨损。转动微动现象广泛的存在于工业设备、民用机械及医疗器械中,其造成的事故比比皆是,每年由于转动微动磨损带来的损失不可估量。涂层材料对微动磨损与疲劳有很好的防护作用,而CrN和AlCrN涂层作为耐磨涂层用于解决转动微动模式下磨损问题有着很大的前景,如应用在高档主轴承和球阀等零部件中表现出了优异的耐磨性,然而迄今为止关于这两种涂层的转动微动摩擦磨损特性的研究鲜见报道。本文利用新型转动微动磨损试验装置,采用球／平面接触,对磨副为Si3N4陶瓷球,研究了物理气相沉积制备的CrN和AlCrN涂层在不同法向载荷(Fn=10N、20N、40N)和不同转动角位移幅值(θ=0.125°、0.25°、0.5°、1°、2°)条件下的转动微动摩擦磨损行为。在分析摩擦动力学行为的基础上,用扫描电子显微镜(SEM)、表面轮廓仪、电子能谱仪(EDX)分别对涂层的磨损形貌、磨痕轮廓、磨损表面和磨屑的成分进行微观分析,对两种涂层转动微动损伤特征进行了讨论,得到以下结论： 1.转动微动参数对CrN和AlCrN涂层的界面摩擦状态具有重要影响,两种涂层的转动微动运行区域依赖于法向载荷和转角位移幅值,随着法向载荷的降低或转角位移幅值的增加,涂层转动微动从部分滑移向完全滑移转变,相同工况下AlCrN涂层较CrN涂层更容易趋于部分滑移状态。 2.CrN和AlCrN涂层的摩擦系数演变趋势极大地取决于所对应的微动状态,涂层在完全滑移状态下的摩擦系数较部分滑移的高,两种涂层摩擦系数值随法向载荷的增大而降低,随转动角位移幅值增大而增大,摩擦系数爬升阶段对应的循环次数随着法向载荷的增大而明显增加,但随转动角位移幅值增大而减少。在高载荷(Fn=40N)时,不同转角位移幅值下CrN涂层的摩擦系数稳定值都明显较AlCrN涂层的低。AlCrN涂层摩擦系数随着转角位移幅值的增大而明显增大,且曲线走势存在明显差异,而转角位移幅值的变化对CrN涂层的摩擦系数值影响不大。 3.两种涂层在摩擦界面为部分滑移状态时,摩擦界面损伤较为轻微,产生的磨屑很少,而在完全滑移状态时,转动磨损损伤是二体作用和三体作用共同作用的结果,角位移幅值的增大涂层进入完全滑移状态后的损伤明显加重,产生较多的磨屑并分布在磨痕两端。高法向载荷(Fn=40N)下,转角位移幅值对两种涂层的转动微动损伤行为有重要影响,转动角位移幅值由1°增大为2°后,两种涂层在磨痕中心处的磨损特征以及排屑行为都存在明显的差异,主要为CrN涂层磨痕内有较明显的磨屑碾压堆积,而AlCrN涂层具有较好的排屑行为,磨痕中心处有明显的塑性累积隆起的痕迹。完全滑移状态下两种涂层的损伤随转角位移幅值的增大而明显加重,但磨损机理都主要为磨粒磨损和轻微的氧化磨损。
[Abstract]:Physical vapor deposition (PVD) of three yuan Cr-Al-N coating formation preparation technology of CrN coating and CrN after joining Al has excellent comprehensive performance, has been successfully used in cutting tools, dies, bearings and piston ring wear parts surface, AlCrN coating with high A1 content because of its excellent high temperature oxidation resistance and the abrasive wear performance is becoming the most typical representative of a new generation of three yuan PVD nitride coatings. Rotational fretting wear is under alternating load side contact wear caused by relative movement of the rotational fretting. It widely exists in industrial equipment, civil mechanical and medical devices, the accident caused by meet the eye everywhere, every year because the rotational fretting wear bring immeasurable loss. The coating material on the fretting wear has good protective effect and fatigue, while the CrN and AlCrN coatings as wear-resistant coating is used to solve the rotational fretting mode Wear problems have great prospects, such as applications in high-grade main bearings and ball valves and other parts, showing excellent wear resistance. However, up till now, the research on the rotational fretting wear characteristics of the two coatings has rarely been reported.
In this paper, using a new rotational fretting wear test device, using a ball / plane contact of the friction pair of Si3N4 ceramic ball, on the physical vapor deposition of CrN and AlCrN coatings to load in different methods (Fn=10N, 20N, 40N) and different angular displacement amplitudes (theta =0.125 degrees, 0.25 degrees, 0.5 degrees, 1 degrees, 2 degrees) under the condition of rotational fretting wear behavior. Based on the analysis of the dynamic behavior of friction, using scanning electron microscopy (SEM), surface profiler, electron spectrometer (EDX) respectively on the wear morphology of the coating, wear contour, wear surface and wear debris of micro components analysis of two kinds of coating rotary fretting damage characteristics are discussed, and get the following conclusions:
1. rotational fretting parameters has important influence on interface friction state of CrN and AlCrN coating, two coating rotational fretting region depends on the normal load and the angular displacement amplitude. With the increase of the normal load decreases and angular displacement amplitude, rotational fretting coating changes from partial slip to slip under the same conditions, AlCrN coating a CrN coating is easy to tend to the partial slip condition.
The friction coefficient of 2.CrN coating and AlCrN evolution depends greatly on the micro state of the friction coefficient of the coating in full slip condition with partial slip is high, two kinds of coating friction coefficient with the normal load decreases, and increases with the rotating angular displacement amplitude increases, the friction coefficient corresponding to the ascent stage number of cycles with the normal load significantly increases, but with the rotation angular displacement amplitude decreases. Under high load (Fn=40N), different angular displacement amplitudes and stable friction coefficient values of CrN coating.AlCrN coating low friction coefficient of AlCrN coating was significantly increased with the increase of the angular displacement amplitude. There are obvious differences and curve trend, and the variation of the angular displacement amplitude the friction coefficient of CrN coating value has little effect.
3. two kinds of coating on friction interface for partial slip condition, the friction interface damage is slight, the wear debris produced little in the full slip state, rotating abrasion injury is the common two body and three body effect, increase the amplitude of displacement angle of coating completely into the sliding state after the injury was aggravated, to generate more debris and distribution in grinding ends. High normal load (Fn=40N), angular displacement amplitude has great influence on the two kinds of coating the rotational fretting damage behavior, angular displacement amplitude increases from 1 degrees to 2 degrees, two kinds of coating on the wear scar at the center of the wear characteristics and discharge chip behavior are significant differences, mainly for CrN coating wear has obvious rolling debris accumulation, while the AlCrN coating has good chip behavior, has obvious plastic cumulative traces of uplift wear at the center. Two under full slip state The damage of the coating is obviously aggravated with the increase of the angular displacement amplitude, but the wear mechanism is mainly abrasive wear and slight oxidation wear.

【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TG174.4;TH117.1

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