刀具表面超晶格TiN/AlN纳米多层膜的制备及性能的研究

采用脉冲多弧离子镀技术制备TiN／AlN纳米多层膜，对该薄膜的结构研究表明，随着调制周期的减小，稳定态六方AlN相逐渐转变成亚稳态立方AlN相，形成以TiN／AlN超晶格结构为主的薄膜。并从与标准图谱的对比中可知．TiN／AlN超晶格是AlN在立方TiN簿膜的影响下，在TiN层上以亚稳态相立方结构外延生长所形成。另研究显示，TiN／AlN薄膜具有一定的超硬效应以及在硬质合金刀具上优良的使用性能。     

磁控溅射沉积Al/AlN纳米多层膜的摩擦学性能

纳米多层膜因具有优异的力学性能与抗摩擦磨损性能使其在摩擦学领域具有重要的应用价值。采用磁控溅射沉积法制备了Al、AlN单层薄膜与Al/AlN纳米多层膜,探讨了纳米多层化对薄膜的力学性能和摩擦学性能的影响。采用纳米压痕仪和摩擦磨损试验机测量评价薄膜的纳米硬度和摩擦学性能。结果表明:Al/AlN纳米多层膜具有良好的周期调制结构,多层膜中的大量界面能显著提高薄膜的力学性能与摩擦学性能。多层膜的硬度为8.8GPa,高于采用混合法则计算出的硬度值6.6GPa;多层膜具有软质Al层和硬质AlN层的交替结构,在摩擦过程中,硬质AlN层可以起到良好的承载作用,软质层可以起到良好的减摩作用。相对于Al单层薄膜或AlN单层薄膜,Al/AlN纳米多层膜具有较低的摩擦因数(0.15)和优异的抗磨损性能。     

调制结构对TiN/TaN多层膜的生长行为及力学性能的影响

利用反应磁控溅射方法，制备了调制周期相同而调制比不同的TiN／TaN多层膜．利用XRD，HRTEM和纳米压痕仪分别对多层膜的结构、微观状态和力学性能进行了系统研究．结果表明：调制结构不仅改变多层膜的生长速率，而且能导致多层膜择优生长取向的变化；界面应力的存在使得薄膜生长速率随沉积层厚度的增加而下降；在TiN／TaN多层膜中存在着各自独立外延生长的[111]和[100]两种取向的调制结构，且具有不同的调制周期；调制周期为6nm左右的TiN／TaN多层膜的硬度与弹性模量分别提高约50％与30％；在调制比为3：1时，硬度最大值为34．2GPa，弹性模量为344．9GPa；根据结构和力学性能的分析结果，讨论了TiN／TaN多层膜的硬化机制．     

Characterization and wear properties of nanoscaled TiN/TaN multilayer coatings

The structural, morphological, mechanical and tribological characterization of nanoscaled multilayer TiN/TaN coatings deposited by magnetron sputtering technology were investigated by low angle X-ray diffractometry, high angle X-ray diffractometry, atomic force microscopy, microhardness, pin-on-disc testing and 3-D surface profiler. The results show that the TiN/TaN coatings exhibit good modulation period and sharp interface between TiN and TaN layers. In mutilayered TiN/TaN coatings, TiN layers have cubic structure, but hexagonal structure emerged among TaN layers besides cubic structure as modulation period is beyond 8.5 nm. The mierohardness is affected by modulation period and the maximum hardness value of 31.5 GPa appears at a modulation period of 8.5 rim. The coefficient of friction is high and the wear resistance is improved for TiN/TaN coatings compared with those of TiN coating; the wear mechanism exhibits predominantly ploughing, material transfer and localized spallation.     

多层膜晶界和膜界间竞比变形及其对硬度测量的影响

使用磁控溅射法制备了不同调制波长的Ni/Al多层膜,利用X射线衍射(XRD)和高分辨电子显微术(HRTEM)对薄膜进行了微结构表征,采用连续刚度法(CSM)研究了不同压入深度下多层膜的硬度.结果表明,随调制波长减小,薄膜呈纳米晶结构特征且存在超硬效应.调制波长L大于30nm时,纳米压入硬度随压入深度的增加而升高;L小于30nm时,最大压入深度的硬度测量值反而最小.同时发现压入深度较小时硬度相对大小对调制波长不敏感.结合微结构表征,从晶界和膜界的竞比变形角度进行了分析讨论.     

TiN/ZrO2 multilayers synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition

TiN/ZrO₂ multilayers with different modulation periods were synthesized on GCr15 bearing steel using plasma immersion ion implantation and deposition (PIIID). The total thickness of the TiN/ZrO₂ multilayers was approximately 2 μm and the modulation period was varied from 8 to 400 nm. The as-deposited films were characterized by scanning electron microscopy (SEM), micro-hardness, friction, scratch and corrosion tests. The SEM result indicates that the structure of the TiN/ZrO₂ multilayers has a good periodicity. Micro-hardness testing results show that the hardness enhancement effect takes place at the specific period of 15 nm, 100 nm and 200 nm. In addition, the friction coefficient declined from 0.8 to 0.1-0.3 and the cut-through number was increased greatly. The critical load in the scratch test exceeds 100 N, which shows a high adhesion strength. Moreover, the corrosion resistance of the TiN/ZrO₂ multilayers was improved significantly at the modulation period of 100 nm and 200 nm.     

钛合金表面百微米级Ti/TiN多层复合涂层性能研究

目的提高TiN硬质涂层的厚度及各项力学性能。方法采用等离子增强PVD技术在钛合金(TC4)基体表面制备多层复合Ti/TiN涂层,对涂层进行扫描电镜(SEM)分析,采用划痕法表征涂层的结合强度,用维氏显微硬度计测试涂层的显微硬度,利用销盘式摩擦磨损试验仪评价涂层的摩擦磨损性能。结果制备的多层复合Ti/TiN涂层厚度最高可达100μm,且未发生剥落等失效,结合强度相对于单层TiN提高了近3倍。由于Ti、TiN的多层复合调制作用,制备的Ti/TiN显微硬度测试表明复合涂层的显微硬度高达2700 HV0.025,同时,涂层在原有耐磨性能优良的基础上具备自润滑减摩作用,经过近20 000 m的磨损测试,复合涂层的摩擦系数低至0.25左右,且未完全失效。结论多层复合结构能够有效提高TiN硬质涂层的厚度,制备的Ti/TiN多层复合涂层的各项力学性能显著提高。     

调制周期对TiN/Ti多层膜组织结构和结合力的影响

为了阐明调制周期对薄膜微观组织及薄膜与基体结合力的影响,采用反应磁控溅射在Ti6Al4V基板上交替沉积了Ti层及TiN层制备了TiN/Ti多层膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度仪和划痕仪测量分析了薄膜的晶体结构、微观组织、硬度以及薄膜与基体之间的结合力。研究结果表明:TiN/Ti多层膜中均存在TiN,Ti和Ti2N 3种相。TiN/Ti多层膜均以柱状晶方式生长,在调制周期较大(5层)时,TiN和Ti层的界面清晰;随着调制周期的减小(层数增加),TiN和Ti层的界面逐渐消失。与单层TiN薄膜相比,多层TiN/Ti薄膜的硬度显著提高;但随着薄膜层数的增加,多层TiN/Ti薄膜硬度略微降低。当调制周期为80nm(30层)时,薄膜与基体的结合力明显提高,达到73N。     

Plasma and ion-beam-assisted deposition of multilayers for tribological and corrosion protection

Multilayers of Ti/TiN and Al/AlN were deposited on steel and silicon by magnetron sputtering and ion-beam-assisted deposition. Compositions and film thicknesses were determined by Rutherford backscattering. Hardness was measured with a dynamic ultramicrohardness tester. The corrosion protection potential in an aqueous environment was evaluated by electrochemical techniques. The results are discussed in terms of the structure and composition of the multilayer arrangement. It turns out that the multilayer coatings generally show a better corrosion protection performance than both the pure metal and the pure nitride films, with an optimum ratio of nitride film thickness to metal film thickness for a maximum corrosion protection effect. The hardness values are in between that of nitride single film and those of metal single films. Deposition of multilayers with the possibility of selecting the thickness ratio of metal to nitride film for particular mechanical and chemical requirements allows a controlled adaption of the film features to a given application problem.     

TiN/Si3N4纳米多层膜硬度对Si3N4层厚敏感性的研究

通过反应磁控溅射制备了一系列不同Si3N4层厚的TiN/Si3N4纳米多层膜,利用X射线衍射仪、高分辨透射电子显微镜、扫描电子显微镜和微力学探针表征了多层膜的微结构和硬度,研究了其硬度随Si3N4层厚微小改变而显著变化的原因.结果表明,在TiN调制层晶体结构的模板作用下,溅射态以非晶存在的Si3N4层在其厚度小于0.7 nm时被强制晶化为NaCl结构的赝晶体,多层膜形成共格外延生长的{111}择优取向超晶格柱状晶,并相应产生硬度显著升高的超硬效应,最高硬度达到38.5GPa.Si3N4随自身层厚进一步的微小增加便转变为非晶态,多层膜的共格生长结构因而受到破坏,其硬度也随之降低.