多层交替膜界限载荷研究

为了研究软硬交替多层表面膜在磨粒作用下的应力应变响应、膜层界面剥离和裂纹的产生及扩展的影响,采用大变形接触弹塑性有限元法对刚性基体上的TiN/Ti多层交替膜在法向压痕作用下的力学行为进行了模拟和分析,研究不同软硬膜层厚度比下,不同膜层的变形、界面切应力分布和表面张应力分布,分析得出界限载荷变化规律及参数分布对其影响情况.结果表明:当软层厚度小于或等于硬层厚度时,增加膜层总厚度可以明显增大多层膜层体系的界限载荷,而软层厚度大于硬层厚度时,增加膜层总厚度不但不能明显增加界限载荷,反而会因增大最大弯曲应力而使界限载荷变小;软硬层厚度比大,而膜层总厚度小的多层膜体系,具有相对较小的最大弯曲应力,因而能承受最大的界限载荷.     

两步压入法--薄膜力学性能的可靠测量方法

提出了采用力学探针测量薄膜力学性能的两步压入法.该方法通过大载荷压入展示基体变形对薄膜硬度的影响,从而选择不影响基体变形的小载荷测出薄膜的硬度和弹性模量.对高速钢基片上的TiN硬质薄膜,单晶硅片上的金属Ni薄膜和(Ti,Al)N/VN纳米多层膜的测量表明,两步压入法能够测出各种性质薄膜的力学性能,并且具有准确可靠的特点.此外,两步法对(Ti,Al)N/VN纳米多层膜的力学性能的测量表明,该体系的纳米多层膜存在硬度和弹性模量异常升高的超硬、超模量效应.     

磁控溅射沉积TiB_2/DLC纳米多层膜的结构及其机械性能研究

采用非平衡磁控溅射系统在P(100)硅片和304不锈钢基底上制备TiB_2/DLC纳米多层膜。利用FESEM、TEM、XRD和AFM观察多层膜的微观结构和表面形貌;利用纳米压痕仪、维氏硬度计和CSM球-盘摩擦磨损试验机考察TiB_2靶电流对多层膜的机械性能和摩擦学性能的影响。结果表明:TiB_2/DLC多层膜具有良好的多层调制结构,多层膜沿TiB_2(101)晶向择优生长;多层膜的表面粗糙度随着TiB_2靶电流增加而增加;多层膜中的大量异质界面能显著提高薄膜的硬度及韧性,而且当TiB_2靶电流为2.0 A时,多层膜的硬度约为单层DLC薄膜的两倍;多层膜中具有硬质TiB_2层和软质DLC层的交替结构,在摩擦过程中,硬层TiB_2起到良好的承载作用,软层DLC起到良好的润滑作用,使多层膜具有比单层DLC薄膜更低的摩擦因数。     

优化TiN/MT-TiCN/Al2O3/TiN多层涂层摩擦磨损性能的研究

通过研究微喷砂处理和使用TiOCN、ZrCN替代TiN顶层对TiN/MT-TiCN/Al2O3/TiN多层涂层摩擦磨损性能的影响,进一步提高TiN/MT-TiCN/Al2O3/TiN涂层刀具的性能.采用化学气相沉积(CVD)在硬质合金基体上沉积TiN/MT-TiCN/Al2O3/TiN、TiN/MT-TiCN/Al2O3/TiOCN和TiN/MT-TiCN/Al2 O3/ZrCN多层涂层,并进行微喷砂处理.采用扫描电子显微镜(SEM)表征涂层的组织结构,采用显微硬度计、划痕测试仪和往复式多功能摩擦磨损实验机(UMT-3)分别对涂层的硬度、结合强度和摩擦磨损性能进行测试.结果 表明:微喷砂处理后,TiN/MT-TiCN/Al2O3/TiN多层涂层的顶层TiN被完全去除,摩擦系数增大,且涂层发生剥落、疲劳磨损严重,耐磨性下降.经微喷砂处理的TiN/MT-TiCN/Al2 O3/TiOCN涂层硬度最高,磨粒磨损程度最轻,且无明显剥落,耐磨性最好.经微喷砂处理的TiN/MT-TiCN/ Al2O3/ZrCN涂层摩擦系数最小,但硬度低,磨粒磨损严重,且涂层存在明显剥落,耐磨性较差.     

钛合金人工心脏瓣膜瓣环表面TiN/Ti多层膜的制备与性能

为了提高钛合金人工心脏瓣膜瓣环TiO_2表面改性层的性能,利用非平衡磁控溅射技术在人工心脏瓣膜瓣环表面制备了具有不同调制周期(44,70,100 nm)的TiN/Ti多层膜过渡层;采用XRD、SEM、显微硬度计及摩擦磨损试验机研究了薄膜的物相组成、横截面形貌、硬度和耐磨性。结果表明:TiN/Ti多层膜由Ti和TiN相组成,当调制周期为100 nm时,TiN/Ti薄膜呈现明显的多层结构,具有高硬度和良好耐磨性;人工心脏瓣膜瓣环表面各个位置TiN/Ti多层膜的相结构及性能相同,可望应用于人工心脏瓣膜瓣环的TiO_2表面改性层的过渡层。     

电弧离子镀制备TiN/TiSiN多层涂层及其性能研究

为提高单一TiN涂层的性能，采用AS600DMTXBE型阳极层离子源辅助电弧离子镀系统制备TiN层和TiSiN层厚度比分别为1∶2、2∶2、3∶1的TiN/TiSiN多层涂层。研究不同厚度比的TiN/TiSiN多层涂层的形貌、结构以及性能，并与TiN涂层性能进行比较。结果表明：TiN/TiSiN多层涂层为TiN面心立方结构，其中厚度比为2∶2的TiN/TiSiN多层涂层的TiN(111)衍射峰较强；厚度比为1∶2的TiN/TiSiN多层涂层摩擦因数最低，表明掺入Si的含量越大，涂层减摩性能越好；TiN/TiSiN多层涂层的减摩作用、硬度和结合强度都优于TiN涂层，且厚度比为2∶2的TiN/TiSiN多层涂层的硬度和结合强度均最大；厚度比为2∶2的TiN/TiSiN多层涂层的耐腐蚀性最高，表明Si元素的掺入能够提升涂层的耐腐蚀性能。     

17-4PH不锈钢表面TiO_2膜及其多层膜的结构与性能

利用非平衡磁控溅射技术在17-4PH不锈钢表面分别制备了TiO_2膜、TiO_2/Ti多层膜及TiO_2/Ti/TiN/Ti多层膜,采用XRD、表面轮廓仪、显微硬度仪、摩擦磨损试验机和水蒸气疲劳腐蚀试验设备研究了薄膜的物相、显微硬度、耐磨性和耐疲劳腐蚀性能。结果表明:具有表面薄膜17-4PH不锈钢的硬度、耐磨性和耐腐蚀性能均有较大提高;与TiO_2膜和TiO_2/Ti/TiN/Ti多层膜相比,TiO_2/Ti多层膜耐磨性能最好,较基体的提高了20倍以上,同时其耐疲劳腐蚀性能也最好。     

Ti/TiN复合膜工艺优化及性能研究

利用正交试验和极差分析方法，分析了多弧离子镀Ti／TiN复合膜中工艺参数（弧电流、氮气分压、基体负偏压、钛过渡层厚度）对Ti／TiN复合膜的纳米硬度和膜与基体的结合力的影响及主次关系，并通过正交试验对工艺参数进行了优化。研究表明，氮气分压和弧电流是影响Ti／TiN复合膜纳米硬度的2个最主要因素，膜层与基体的结合力随着弧电流的增加而下降；升高基体负偏压，虽然可以提高Ti／TiN复合膜纳米硬度和膜与基体的结合力，但是高负偏压将急剧升高基体温度，可能导致基体退火；沉积一定厚度的钛过渡层可以显著提高TiN膜层与基体的结合力。     

MoSx/MoSx-Mo纳米多层膜的制备及其环境摩擦学特性

用直流磁控溅射在钢基体上交替溅射制备了MoSx/MoSx-Mo纳米多层膜。采用划痕仪测试薄膜与基体的结合力;采用SEM和XRD分析了纳米多层膜的形貌和显微结构;在球-盘式微摩擦试验机上测试了纳米多层膜在真空和潮湿空气中的摩擦学性能。结果表明,纳米多层膜的结合力优于纯MoS2膜。随着溅射沉积气压的升高,MoSx(002)面择优取向减弱,纳米多层膜的结合力下降。溅射气压0.24 Pa沉积的纳米多层膜在真空和潮湿空气中都呈现出最低的摩擦因数和磨损率,具有优异的环境摩擦磨损特性。     

多弧离子镀制备纳米多层TiAlSiN涂层的性能研究

采用多靶阴极电弧离子镀系统在硬质合金基体上沉积纳米多层结构的Ti Al Si N硬质涂层,该结构是通过Ti Al N涂层与Ti Si N涂层的交替叠加而制备的。实验同时制备了Ti Al N涂层、Ti Al Si N单层涂层与纳米多层涂层进行性能对比分析,用扫描电镜(SEM)、EDS对涂层结构形貌及成分进行了分析,用划痕法和纳米压痕法分别对涂层的结合力与纳米硬度进行了测试,同时也测试了涂层在不锈钢车削上的性能表现。结果表明,Ti Al Si N纳米多层涂层硬度高达33 GPa,同时在不锈钢车削上以Ti Al Si N纳米多层涂层性能最优,而Ti Al Si N单层涂层性能最差。     

High-resolution scanning electron microscopy study of sputtered nanolaminated Ti/TiN multilayers

This work presents the morphologic and structural study of nanolaminated Ti/TiN multilayers using high-resolution scanning electron microscopy (HR-SEM), coupled to x-ray reflectometry (XRR). The multilayers have been deposited by reactive rf-sputtering on silicon substrates. For large period thickness (lambda=40 nm, 10 periods), in XRR, the low number of interfaces makes the interference less structured. An experimental pattern with broad and weakly intense Braggs peaks is obtained, but is difficult to simulate. On the other hand, HR-SEM observation of cross sections gives excellent pictures of the multilayer, so that precise measurements of the thickness can be achieved: a 42 nm thick period is observed, formed with 17 nm of Ti and with 25 nm of TiN. For small (Ti+TiN) period thickness (lambda=2.5 nm, 120 periods), the XRR pattern exhibits intense and narrow Bragg peaks: the number of interfaces is sufficient to structure the interference and an intense signal is obtained. The best fit of simulation is obtained for a 2.6 nm thin period, made of 0.9 nm of Ti and 1.7 nm of TiN. No laminated structure has been observed by cross-section HR-SEM observation because its resolution (around 2 nm at 10 kV) is larger than the layer thickness in a period. High-resolution SEM and XRR are thus two complementary techniques for the routine characterization of multilayers.     

亚四分之一波长宽波段多层膜的设计

简要阐述了强吸收波段亚四分之一波长多层膜的设计方法。这种膜系是由强吸收材料叠加而成,每层膜光学厚度小于四分之一个波长。与常规周期多层膜相比,这种膜系更适用于提高强吸收波段的反射率。利用该方法设计了50nm~110nm波段宽带高反膜的初始膜系,通过Levenberg-M arquart方法对初始膜系进行优化,从而得到宽波段的平坦反射率,其平均反射率达到45%。     

力学薄膜的多层化强化

采用多层膜系是进一步提高诸如TiN等力学薄膜性能的有效方法之一,综述了有关方面的研究情况,目前已经投入应用的各种氮化物薄膜是最简单的多层膜的原型,其内设的过渡层可改善膜/基附着力;多层膜性能与组层结构有关,适当的层间厚度（调制周期）可显著提高多层膜的力学性能,适当的亚层组合可获得同时兼具高硬度和良好韧性的力学薄膜。     

eXTP望远镜用W/Si多层膜

针对增强型X射线时变与偏振探测卫星(eXTP)项目中嵌套式聚焦成像望远镜对柱面镜片上W/Si多层膜的要求,在掠入射角为0.5°,工作波段为1~30keV条件下,设计了非周期W/Si多层膜并优化了薄膜制备工艺。首先,利用分隔板和掩模板对溅射粒子进行准直,同时优化了本底真空度和溅射工作气压,提升了薄膜的成膜质量;然后,通过调整分隔板间距和公转速率提升了在柱面基底上薄膜的沉积均匀性;最后,利用幂指数算法设计了非周期多层膜,并在北京同步辐射光源上进行了多能点反射率测试,得到了与理论设计基本吻合的测试结果。基于优化的制备工艺制备了周期数为80,周期为3.8nm和W膜层厚度占比为0.47的W/Si周期多层膜,其界面粗糙度仅为0.29nm,柱面镜薄膜厚度误差可控制在3%以内,基本满足了eXTP项目中嵌套式掠入射望远镜镜片用多层膜对于成膜质量、沉积厚度均匀性和能谱响应宽度的需求。     

多层金属/介质膜系中Al层的作用分析

设计了一维金属/介质多层膜系,膜系由几个周期的高折射率(Al₂O₃)/低折射率(MgF₂)材料所组成.在低折射率材料中插入金属层(Al),对膜系进行了优化,利用电子束蒸发方法制备了该膜系.实验表明,不仅Al层的总厚度直接影响透射谱的形状,在同样Al层总厚度情况下,Al层厚度分布对膜系也有影响.寻找到了最佳Al层分布结果,并通过了实验验证,制备出了能很好抑止BaF2晶体发射光谱的长波成分的膜系.     

Comparison of tribological characteristics of nanostructured TiN,MoN, and TiN/MoN Arc-PVD coatings

The tribological properties of TiN, MoN, and TiN/MoN coatings have been investigated. It has been shown that, for multilayer (alternate) TiN/MoN coatings, a maximum hardness reaches 29–31 GPa that is significantly less than the hardness of MoN coatings (36.0–40.2 GPa) when changing the deposition conditions. MoN coatings possess lower coefficients of friction compared to TiN coatings, in particular at the initial stages of a scratch test. Two mechanisms of destruction are revealed by the adhesion tests, i.e., a cohesive failure with a minimum critical loading L _C1 and an adhesive test (plastic abrasion) with the appearance of a first crack L _C2. The resistance of multilayer (nanoscale) nanostructured TiN/MoN coatings with a total thickness of up to 8 μm is greater than that of TiN coatings.     

Al/Zr多层膜生长模型和数值计算

在17～19nm波段,利用直流磁控溅射技术将Al(1%wtSi)/Zr多层膜镀制在掺氟的二氧化硅基底上,基于原子力显微镜对不同膜对数(N=10,40,60,80)表面粗糙度的测量结果,将多层膜的生长模型应用于实际结果中,对表面均方根粗糙度随着膜对数的变化进行了深入的分析,并对Stearns粗糙度动态生长理论的适用条件作了补充性讨论。     

TiN复合渗镀层摩擦磨损性能的研究

介绍了一种同时利用等离子尖端放电、空心阴极效应和反应气相沉积技术,在碳钢表面形成具有扩散层和沉积层的TiN复合渗镀层新工艺技术。对TiN复合渗镀层、TiN复合渗镀层+TiN薄膜(PVD法)以及在碳钢基体表面直接沉积TiN薄膜(PVD法)这三种工艺试样的表面形貌、硬度、摩擦磨损进行了对比研究。结果表明TiN复合渗镀层+TiN薄膜,其表面形貌是较为均匀、致密、细小的胞状物组织,平均硬度达到2500HV左右,磨损曲线最平稳、平均摩擦系数最小,耐磨性比较好。复合渗镀层厚度可达十几微米以上,并且成分、硬度、结构均呈梯度分布,与基体是冶金结合,结合力非常好,所以其磨痕最浅。     

Tribological and structural characterization of a physical vapour deposited TiC/Ti(C,N)/TiN multilayer

A physical vapour deposited TiC/Ti(C,N)/TiN multilayer was investigated and compared with a PVD TiN monolayer coating in a ball-on-disc test. Wear and friction against a corundum ball were measured as a function of time and sliding velocity. In these experiments, the coefficient of friction remained constant at 0.2 as long as the ball was sliding on TiC or intermidiate Ti(C,N) layers. When the TiN layer was reached, the coefficient of friction became unstable and rose to an average value of 1–1.5, which is characteristic for a TiN/Al₂O₃ contact. Wear rates for the multilayer were found to be three to four times smaller as compared to the reference TiN. The multilayer morphology of the TiC/Ti(C,N)/TiN was revealed in a low-angle cross-section resulting from a prolonged ball-on-disc test. In that way, it was shown that the multilayer consisted of nine separate sublayers.     

Abrasive Wear of DLC/PVD Multilayer Coatings: AFM Studies

The tribological behaviour of multilayered coatings deposited on plain carbon steel was investigated by microscale abrasion tests (MSATs). The multilayered coatings consisted of an outer diamond‐like carbon (DLC) layer, a physical vapour deposition (PVD) nitride‐based interlayer, and an inner electroless Ni‐P layer. PVD TiN‐ and Ti(C,N)‐coated samples with and without the DLC outer layer were studied in order to evaluate the influence of each layer on the tribological behaviour of the multilayer‐coated system. The MSATs were carried out using a device based on ball‐cratering geometry: a hard steel sphere was rotated against the coated specimen in the presence of an aqueous suspension of SiC particles. The wear coefficients of the multilayers were calculated from the diameter of the wear craters. The morphology of the wear scars produced by the MSATs was studied by atomic force microscopy (AFM). The wear damage was described by measuring the r.m.s. roughness (S_q) on the sides of the wear craters. Roughness values were related to the wear coefficients (k_c) for the different multilayers on the basis of mathematical elaboration typical of the ‘design of experiment’ (DOE) statistical technique. The presence of the DLC outer layer reduced the roughness of the crater sides and significantly increased the wear resistance of the multilayer only in the case of the PVD TiN sublayer.