Effects of titanium-implanted pre-treatments on the residual stress of TiN coatings on high-speed steel substrates

This investigation examined how titanium ion implantation pre-treatment affects the residual stress of TiN coatings on M2 high-speed steel. Ions were implanted by metal plasma ion implantation. The adhesion strength of the TiN coatings was enhanced by pre-treatment that implanted Ti into the M2 tool steel substrate. The implanted substrate functioned as a buffer layer between the deposited TiN and the tool steel substrate, resulting in variations of the residual stress. The residual stress determined by glancing-angle XRD demonstrates that the deposited TiN films on ion-implanted substrates exhibited reduced compressive stress, from − 3.95 to − 2.41 GPa, which corresponded to a decrease in the grain size of the TiN films. The texture of the TiN film was clearly transformed from the preferred orientation of (220) to (111), subsequently enhancing wear resistance against a tungsten ball.     

Off-axis texture in nanostructured Ti1 − xAlxN thin films

Standard θ-2θ and pole figure X-ray diffraction techniques were used to study structural properties and preferred orientation of nanostructured TiAlN thin films prepared using cathodic arc deposition. Systematic collection of reflections from lattice planes {111}, {200}, {220}, and {311} showed that the in-plane orientation of crystallites exhibits cylindrical symmetry with random distribution of crystallites, while the out-of-plane growth presents strong texture which is inclined with respect to the surface normal. This brings the crystallographic orientation of fibre texture towards high indices lattice planes (113) and (115) contrary to traditionally grown films that develop a preferred orientation following to low indices close-packed planes (111) and (200). The origin of inclined growth is discussed taking into account the role of crystallographic defects in particular twin faults that develop in the lattice of growing crystal and change the stacking sequences of atom layers.     

Hydrothermal corrosion of TiN PVD films on SUS-304

Hydrothermal corrosion of thin TiN PVD films (3 μm thickness) at 100 MPa water and 20-800 °C temperature range was studied. Noticeable oxidation starts above 200 °C and acceleration of oxidation processes takes place in hydrothermal conditions in comparison with airflow oxidation of corresponding PVD films and air oxidation of TiN powders. The formation of Ti_nO_2n−1 homological series phases and regular single crystals in oxide scale were observed. FeTiO₃ ilmenite layer secures high protective properties at 600 °C and practically does not contain chromium. Therefore, usual low alloy steel with TiN coating can be used instead superalloy for wet air oxidation system with working temperature up to 600 °C.     

热处理对两种铜膜结合强度的影响

采用PVD和CVD技术制备Cu/TiN/PI试样，研究表明，TiN薄膜可以有效地阻挡Cu向PI基板内部扩散，CVD工艺制备的Cu膜内部残余应力很小，Cu膜有相对高的结合强度；而PVD制备的Cu膜，在有TiN阻挡层存在的情况下，Cu膜内存在拉应力，拉应力降低了Cu膜结合强度，300℃退火可以消除膜内残余应力，结合强度提高。     

Deposition of TiN thin films on Si(100) by HCD ion plating

Titanium nitride (TiN) films were deposited on Si(100) substrates using a hollow cathode discharge ion plating (HCD-IP) technique. Based on previous experimental results, the optimum deposition conditions were chosen. The thickness of the TiN film and the angle between the specimen surface and the evaporating source (coating angle) were selected as the variable parameters. The purpose of this study is to investigate the effect of these two processing parameters on the properties of TiN films. After deposition, the thin film structure was characterized by X-ray diffraction (XRD), cross-sectional transmission electron microscopy (XTEM), and field-emission-gun scanning electron microscopy (FEG-SEM). N/Ti ratios of the thin films were determined using both X-ray photoelectron spectrometer (XPS) and Rutherford backscattering spectrometer (RBS). The resistivity of the TiN films was measured by a four-point probe. The hardness of the thin films was obtained from nanoindentation tests. An atomic force microscope (AFM) was used to measure the roughness of the thin films. The results showed that (111) was the dominant preferred orientation in the TiN films for most of the deposition conditions and for all coating angles, especially for film thicknesses greater than 1 μm. Hardness values of TiN films were approximately 28 GPa for film thicknesses close to 0.5 μm and above, and did not vary with the coating angle. The hardness can be correlated to the (111) preferred orientation of the TiN film. The hardness increased with the (111) texture coefficient and leveled off as the texture coefficient approached 1. The packing factor had a linear relationship with the film thickness. Resistivity decreased with increasing thickness and increasing packing factor for all coating angles. At a similar thickness or packing factor, specimens coated at angles different from 0° had a much higher resistivity than those coated at 0°.     

Combinatorial approach to the growth of α-(Al1 − x,Crx)2O3 solid solution strengthened thin films by reactive r.f. magnetron sputtering

The development of new coatings with superior functionalities for high performance cutting tools is a key challenge in manufacturing. In this context, the synthesis of aluminium oxide and derivative oxide thin films is attracting large scientific and technical interests. The present paper addresses fundamental materials science-based aspects of the physical vapour deposition (PVD) growth of Al-Cr-O thin films at a substrate temperature of 500 °C. A combinatorial experimental approach was chosen to describe the growth and microstructure evolution of Al-Cr-O thin films by means of reactive r.f. magnetron sputtering. A segmented target consisting of two half plates of Al and Cr was used for the deposition carried out under stationary conditions in a laboratory-scale PVD coater. Opposite to the cathode five substrate samples were placed in a line. The r.f. cathode power was set to 500 W and the r.f. substrate bias was set to − 100 V. The total gas pressure was kept constant at 0.4 Pa for all experiments with a fixed ratio of oxygen to argon gas flow. Detailed results on the coatings composition, constitution, microstructure and properties as a function of the elemental composition are presented. X-Ray Diffraction (XRD), X-Ray Reflection (XRR), Transmission Electron Microscopy (TEM) and Electron Probe Microanalysis (EPMA) studies prove the growth of nanocrystalline, stoichiometric, metastable corundum-like solid solution strengthened α-(Al_1 − x,Cr_x)₂O₃ thin films with a high degree of crystallinity, grain sizes between 27 ± 6 nm (in the case of Al-rich coatings) and 44 ± 17 nm (in the case of Cr-rich coatings), Vickers micro hardness values up to 2620 ± 80 HV0.05 and thin film densities between 4.00 g/cm³ (in the case of Al-rich coatings) and 4.86 g/cm³ (in the case of Cr-rich coatings).     

Influence of surface topography of arc-deposited TiN and sputter-deposited WC/C coatings on the initial material transfer tendency and friction characteristics under dry sliding contact conditions

The influence of surface topography of PVD coatings on the initial material transfer tendency and friction characteristics in dry sliding contact conditions has been investigated. A modified scratch test was used to evaluate the material transfer tendency between ball bearing steel and two different PVD coatings, TiN and WC/C, under dry sliding contact conditions. Post test characterisation of the contact surfaces was performed using SEM/EDS and AES in order to map the initiation points and mechanisms for material transfer. The results show that the resulting topography of the PVD coated surfaces is strongly dependent on both the substrate material topography and the topography induced by the coating deposition process used. In sliding contact with a softer surface the coating topography results in a significant material pick-up tendency of the PVD coated surfaces. The material pick-up is mainly controlled by the abrasive action of hard coating asperities and as a result a polishing post treatment of the as-deposited PVD coatings significantly reduces the material pick-up tendency. For the WC/C coating, showing intrinsic low friction properties, the post treatment inhibits the material pick-up and results in a low and stable friction coefficient (μ ~ 0.1). For the TiN coating, that lacks intrinsic low friction properties, the post treatment reduces the material pick-up tendency but has no significant influence on the friction characteristics. This is mainly due to the presence of metallic Ti originating from the macroparticles on the TiN coating which results in a reactive surface that promotes a strong adhesion between the mating surfaces.     

热处理对PI基板铜薄膜金属化TiN阻挡层的影响

聚酰业胺(PI)材料具有介电常数低，分解温度高及化学稳定性好等优点，是很有前途的电子封装材料。Cu具有低的电阻和高的抗电迁移能力，足PI基板金属化的首选材料。采用物理气相沉积(PVD)方法在PI基板上沉积Cu薄膜，利用TiN陶瓷薄膜阻挡Cu向PI基板内部扩散。研究热处理条件下TiN陶瓷薄膜阻挡层的阻挡效果、Cu膜电阻变化以及Cu膜的结合强度，俄歇谱图分析表明TiN可以有效地阻挡Cu向PI内的扩散。300℃热处理消除了Cu膜内应力，提高了Cu膜的结合强度。     

A comparative study of the properties of TiN films deposited by MAIP and FCAP

In this study two types of TiN films were prepared, one using the filtered cathodic arc plasma (FCAP) technique with an in-plane “S” filter, and the other using the multi-arc ion-plating (MAIP), and both deposited under the same parameters. Comparisons of the texture, hardness, roughness, tribological and electrochemical corrosion behaviors of the two types of TiN films were given. The TiN films obtained by the FCAP technology were found to be highly uniform, smooth and macroparticle-free. The TiN films deposited by FCAP had a (111) preferred orientation, while there was no texture in the films deposited by MAIP. Under low load the two kinds of TiN coatings had very different wear mechanisms; the films of FCAP had a lower wear rate and friction coefficient compared with the TiN films deposited by the MAIP technique. The dense and hole-free structure of TiN films of FCAP could effectively avoid the avalanche of TiN films from the substrate during corrosion tests.     

Hydrothermal corrosion of TiAlN and CrN PVD films on stainless steel

Hydrothermal corrosion of thin TiAlN and CrN PVD films (of 3μm thickness) in 100 MPa water over a temperature range of 20-950 °C is compared to the behavior of TiN films over the same T-P conditions. Corrosion resistance increases in the sequence TiN → TiAlN → CrN. A FeTiO₃ (ilmenite) layer on the surface of the TiAlN film is almost chromium-free and provides protective properties up to 700 °C, whilst ülvospinel formation leads to spallation of oxide scale due to high level growth stresses. Formation of a very stable spinel scale on the surface of the CrN films provides long-term corrosion protection in 100 MPa water up to 800 °C. Nitride films on low-alloyed steel can substitute for expensive super alloy in wet air oxidation systems, with working temperatures up to 700 °C in the case of TiAlN, or 800 °C in the case of CrN coatings.     

AISI M2钢上磁控溅射TiN、TiAlN和TiAlVN薄膜的显微结构(英文)

为了研究Al和V掺杂对TiN薄膜微结构的影响,用磁控溅射法在AISI M2高速钢上沉积TiN、TiAlN和TiAlVN薄膜。采用XRD、SEM和TEM对薄膜的显微结构进行表征。结果表明,TiN薄膜中掺杂Al引起了晶格常数的降低,TiAlN中掺杂V则导致晶格常数的增加。另外,TiN、TiAlN和TiAlVN薄膜的生长形态显示,添加Al和V有改善柱状结构的倾向。在TiN、TiAlN和TiAlVN薄膜中鉴定出(111)和(200)晶向,ε(Fe3N-Fe2N)相的存在是因为薄膜中存在少量的Fe。TiAlN和TiAlVN薄膜夹层具有)0101(择优取向。在TiAlN和TiAlVN薄膜中观察到(111)和(200)晶向的织构(柱状)结构,在TiAlVN/M2夹层和回火马氏体之间存在)0101(α-Ti//(110)T.M的位向关系。     

Influence of Si content and growth condition on the microstructure and mechanical properties of Ti-Si-N nanocomposite films

Thin films of Ti-Si-N have been prepared by ion beam assisted deposition (IBAD) from two Ti and Si targets. The silicon concentration in the deposited coatings is varied between 0 and 23.7 at.%. The influence of Si content and growth conditions on the microstructure and mechanical properties were investigated using XPS, AFM, XRD and nanoindenter. These nanocomposite coatings exhibit improved mechanical properties in comparison with TiN deposited under the same condition. The hardness measured by nanoindentation reached 42 GPa in Ti-Si-N films containing 11.32 at.% of Si, whereas TiN films only had a value of about 18 GPa. AFM showed that the finest grain size of Ti-Si-N appeared to be 5 nm when Si content was 11.32 at.%. From XPS and XRD results, the microstructures of the high hardness samples were found to consist of nanocrystal TiN grains and amorphous Si₃N₄.     

直流磁控溅射法在玻璃基片上制备TiN薄膜

采用直流反应磁控溅射法在玻璃片上制备了TiN薄膜,研究不同制备工艺条件与薄膜性能之间的关系。用紫外-可见光分光光度计测试了不同沉积时间和N2流量条件下TiN薄膜透光率;用X射线衍射仪分析了不同N2流量和溅射功率条件下TiN薄膜结构;用扫描电镜(SEM)观察了TiN薄膜的表面腐蚀形貌,用恒电位仪对TiN薄膜的耐腐蚀性进行了分析。结果表明:当沉积时间为2min,N2流量为15mL/min时,在可见光区有较高的透光率,在近红外区的透光率很低;当N2流量为15mL/min,溅射功率为4kW时,TiN薄膜的结晶最致密;当溅射功率为4kW时,TiN薄膜具有较好的耐腐蚀性。     

Oxidation resistance improvement of arc-evaporated TiN hard coatings by silicon addition

Ti-Si-N coatings were deposited on M2 steel by arc evaporation using a Ti-Si composite target in an industrial reactor. The films structure before and after heat treatment at 700 °C was characterised by XRD. In addition, two types of quantitative experiments were performed in thermobalance: oxidation rate was deduced from isothermal thermogravimetric analyses at 800 °C, while the temperature of oxidation beginning (Tc) was measured in dynamic mode. Tc was then calculated by a mathematical approximation based on the non-linear least square. The results were compared to those obtained using TiN and SiN_x standards.Depending on the deposition conditions, ternary films have been deposited with an atomic ratio Si/Ti of 0.10 and 0.15. The hardness of the films was close to 40 GPa. Only the TiN phase was detected by XRD. The mean crystal size was estimated to be in the 6-8 nm range, which suggested the nanocomposite nature of the coatings. After air oxidation at 700 °C, it was found that this crystal size was not affected by the thermal treatment, indicating a good thermal stability of the structure. Moreover, incorporation of silicon into TiN-based coatings led to a drastic decrease of their oxidation rate, together with a shift of 200 °C of Tc. The high resistance of oxidation of Ti-Si-N films at elevated temperature is attributable to the network of refractory SiN_x, which acted as a diffusion barrier for oxygen and insulated TiN nanograins from the aggressive atmosphere.     

Influence of the nanostructuration of PVD hard TiN-based films on the durability of coated steel

The design of thin hard coatings at a nanometric scale is very promising to improve the surface characteristics of coated parts. Unfortunately, most often only one specific property is really enhanced. Besides, the origin of such a “nanostructure effect” remains still not clearly elucidated, and a wider industrial development requires a better understanding of the relations linking structure and functionality.This paper results from an invited review presented within the framework of the EMRS 2007 spring meeting. Its objective is to present how it is possible to control the films structure to achieve optimized performance in terms of tribological, mechanical, and physico-chemical behaviours. Two types of films architecture are studied, resulting either from a stratification of nanolayers, or from a nanodistribution of a crystallised phase into an amorphous matrix. To illustrate both structures, arc-evaporated nanomultilayered TiN/CrN and TiSiN nanocomposite coatings are more particularly developed, and compared to TiN, CrN and SiN_x references.High wear resistance of TiN/CrN is explained by an original propagation mode of the cracks due to a fluctuating residual stress field, evidenced by TEM and synchrotron measurements. Corrosion behaviour depends mainly on the nature of the outer layer. An external CrN layer, presenting a p-type semiconductive character, affords an enhanced protection. A beneficial role of the nanostratification, susceptible to strongly improve the density of films, was also evidenced. The high oxidation resistance of TiSiN is attributable to the network of refractory SiN_x, which acts as a diffusion barrier for oxygen and insulates the highly reactive TiN nanograins from the aggressive atmosphere.     

Properties and performances of innovative coated tools for turning inconel

Three innovative nanostructured coatings have been developed to be applied on cutting tools for continuous cutting of nickel-based super-alloys, in Minimum Quantity Lubrication (MQL) or dry conditions.The coatings, TiN+AlTiN, TiN+AlTiN+MoS₂ and CrN+CrN:C+C, were applied by PVD techniques on WC-Co inserts, developing nanostructured layers, characterised by superior performances, as confirmed both by laboratory tests and machining experiments.Coatings surface qualification included SEM observations with EDS analysis, ball erosion test, nanoindentation and scratch tests, classic tribological evaluation by ball-on-disc set-up, surface texture analysis.Results were analysed in light of the outcome of machining experiments performed mainly in dry and MQL turning of Inconel 718. Ball-on-disc and scratch tests, as well as machining experiments, agreed in classifying the coatings in the following decreasing performance order: TiN+AlTiN+MoS₂, followed by TiN+AlTiN, and by CrN+CrN:C+C.     

TiN, TiN gradient and Ti/TiN multi-layer protective coatings on Uranium

Single-layer TiN, gradient TiN and multi-layer Ti/TiN coating were deposited on silicon and uranium substrates by means of arc ion plating technique. The main phase in the single-layer TiN coating was TiN with a (111) preferred orientation. Ti and TiN were observed in the TiN gradient coating and Ti/TiN multi-layer coatings. The single-layer TiN coating has demonstrated the best wear resistance among the three coatings. Compared with the bare U substrate, the corrosion potential E_corr of the multi-layer Ti/TiN coatings is increased by 580 mV, and the corrosion current density I_corr is decreased at least by two orders of magnitude. The multi-layer Ti/TiN coatings possessed the highest corrosion resistance among the three coating in a 0.5 μg/g Cl⁻ solution.     

Mo离子注入和离子渗硫对TiN涂层微观结构和表面性能的影响

为进一步改善氮化钛涂层的摩擦学性能,分别采用高剂量Mo离子注入和低温离子渗硫技术对Ti N涂层表面进行处理。采用扫描电子显微镜(SEM)、光学形貌仪、扫描俄歇系统(SAM)、X射线衍射仪(XRD)和纳米压痕仪等分析Ti N涂层处理前后的表面形貌、元素分布、微观结构和纳米硬度。利用球盘摩擦磨损试验机在干摩擦条件下考察涂层的摩擦学性能,并利用光学形貌仪和SEM进行磨损表面分析。结果表明,大剂量Mo离子注入后,Ti N涂层表面Mo离子深度接近200 nm,涂层硬度明显降低,涂层磨损剧烈程度得到显著改善,磨损率和摩擦因数分别降低约35%和40%;低温离子渗硫复合处理后,Ti N涂层表面溅射明显,Mo的深度降低约50%,摩擦学性能难以进一步明显改善。     

Evaluation of nanocrystalline TiN films prepared by arc ion plating

Monolayer and multilayer TiN films were synthesized on a SKD 11 steel sheet by an arc ion plating technique and the correlation between the microstructure and properties of the TiN films was comparatively investigated. The results indicated that the main phase was fcc-TiN, showing a (200) preferred orientation in the film under 2.0 × 10⁻¹ torr N₂ partial pressure, whereas a gradual transition to (111) preferred orientation was observed with decreasing N₂ partial pressure to 1.4 × 10⁻¹ torr. The (200) and (111) textures in the film under an arc current of 80 A were found to be competitive orientations, but the (200) texture became stronger as the arc current was increased. Compared to the optimal monolayer TiN films, the multilayer TiN film possessed high hardness of up to 20.3 ± 1.3 GPa and excellent wear resistance. These features are attributed to the presence of dense microstructures that are mainly composed of TiN phase and are around 1.7 μm to 1.8 μm in thickness.     

Thin film processing and multiferroic properties of Fe-BaTiO3 hybrid composite

Multiferroic bi-layer Fe/BaTiO₃ (BTO) thin films were successfully deposited on Pt(200)/MgO(100) substrates using ion beam sputter deposition (IBSD), and the mutiferroic properties were studied at room temperature. X-ray diffraction (XRD) analyses showed that BTO films were c-axis oriented and epitaxially grown on platinum coated MgO substrates, and (110) epitaxial Fe films were subsequently grown on (001) BTO films. Fe/BTO bi-layer films showed good ferroelectric and ferromagnetic properties at room temperature and the multiferroic coupling was observed, which should be attributed to the hybridization of Fe and Ti occurring at the ferromagnetic-ferroelectric interface.