TENSILE AND ADHESIVE STRENGTHS OF FINE TiN FILM ON Ti SUBSTRATE

The cantilever bending test,particularly monitored by an acoustic emission technique, was adopted to measure the tensile and interfacial adhesive strengths of the HCD ion plated fine TiN film on pure Ti substrate.The behaviors of film damaging were found to be characterized by:an internal tensile stress which exceeded its tensile strength for TiN facing upward,and a shearing stress along film substrate interface which exceeded its adhesive strength for TiN facing downward.The measured tensile and adhcsive strengths are 603 and 242 MPa respectively.

The Effect of Diffusion Barrier and Bombardment on Adhesive Strength of CuCr Alloy Films

A novel co-sputtering method that combined magnetron sputtering (MS) with ion beam sputtering (IBS) was used to fabricate CuCr alloy films without breaking vacuum after depositing diffusion barrier with IBS. Different bombardment energies were used to improve the comprehensive properties of Cu alloy film. The results indicated that the effects of diffusion barriers and bombardment energy on adhesive strength could be evaluated by a rolling contact fatigue adhesion test. Diffusion barrier can enhance the adhesive strength, and the adhesion of CuCr/CrN was higher than that of CuCr/TiN. When bombarding energy was higher, the adhesive strength of CuCr/TiN films was higher due to the broader transition zone.

Interfacial Bonding Strength of TiN Film Coated on Si_3N_4 Ceramic Substrate

The fraction of TiN/Si3N4 in the cross section was observed with scanning electric microscope （SEM）, and residual stresses of TiN coated on the surface of Si3N4 ceramic were measured with X-ray diffraction （XRD）.The hardness of TiN film was measured, and bonding strength of TiN film coated on Si3N4 substrate was measured by scratching method. The formed mechanism of residual stress and the failure mechanism of the bonding interface in the film were analyzed, and the adhesion mechanism of TiN film was investigated preliminarily. The results show that residual stresses of TiN film are all behaved as compressive stress, and TiN film is represented smoothly with brittle fracture, which is closely bonded with Si3N4 substrate. TiN film has high hardness and bonding strength of about 500 MPa, which could satisfy usage requests of the surface of cutting Si3N4 ceramic.

Adhesive strength of CVD diamond thin films quantitatively measured by means of the bulge and blister test

Large advancement has been made in understanding the nucleation and growth of chemical vapor deposition （CVD） diamond, but the adhesion of CVD diamond to substrates is poor and there is no good method for quantitative evaluation of the adhesive strength. The blister test is a potentially powerful tool for characterizing the mechanical properties of diamond films. In this test, pressure was applied on a thin membrane and the out-of-plane deflection of the membrane center was measured. The Young＇s modulus, residual stress, and adhesive strength were simultaneously determined using the load-deflection behavior of a membrane. The free-standing window sample of diamond thin films was fabricated by means of photolithography and anisotropic wet etching. The research indicates that the adhesive strength of diamond thin films is 4.28±0.37 J/m^2. This method uses a simple apparatus, and the fabrication of samples is very easy.

ADHESION STRENGTH OF COATING SUBSTRATE AND SURFACE MORPHOLOGY OF PRETREATMENT

Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is conducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.

Development of hyaluronic acid-based edible film for alleviating dry mouth

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were compared.The concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the solubility.The 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among samples.All of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%humidity.The optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years old.By the sensory test,800 F was also the most acceptable.Based on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

Enhanced adhesion of Cu-W thin films by ion beam assisting bombardment implanting

Cu-W thin film with high W content was deposited by dual-target DC-magnetron co-sputtering technology.Effects of the substrates surface treating technique on the adhesive strength of Cu-W thin films were studied.It is found that the technique of ion beam assisting bombardment implanting of W particles can remarkably improve the adhesive property of Cu-W thin films. Indentation and scratching test show that,the critical load is doubled over than the sample only sputter-cleaned by ion beam.The enhancing mechanism of ion beam assisting bombardment implanting of Cu-W thin films was analyzed.With the help of mid-energy Ar+ion beam,W atoms can diffuse into the Fe-substrate surface layer;Fe atoms in the substrate surface layer and W atoms interlace with one another;and microcosmic mechanical meshing and diffusing combination on atom-scale among the Fe and W atoms through the film/substrate interface can be formed.The wettability and thermal expansion properties of the W atoms diffusion zone containing plentiful W atoms are close to those of pure W or W-based Cu-W film.

真空热处理对不锈钢表面TiN薄膜结构及性能的影响

为提高不锈钢材料在海洋环境中的耐腐蚀能力,采用磁控溅射技术在304不锈钢表面沉积TiN薄膜,并在不同温度下对其进行真空热处理,研究热处理温度对TiN薄膜结构及性能的影响。结果表明:适当的真空热处理可提高304不锈钢表面TiN薄膜的结晶度及致密性,缓解其残余应力。与未处理薄膜相比,500℃真空热处理后薄膜内部应力可降低87%,与基底的结合强度提高78%,其腐蚀电流密度由2.42×10^(-6)A/cm^(2)降低到4.43×10^(-7)A/cm^(2),腐蚀电位由-0.247 V提高到-0.044 V,耐腐蚀性能明显提升。

离子束辅助磁控溅射沉积TiN薄膜的研究

利用三离子束辅助沉积设备 ,以离子束辅助沉积、磁控溅射和离子束辅助磁控溅射几种工艺在GCr15基体上沉积TiN薄膜。实验结果表明 :离子束辅助磁控溅射有效地提高了薄膜的硬度、耐磨性和耐蚀性 ,改善了膜基结合力。

基体材料对TiN薄膜表面液滴及薄膜结合力的影响

采用真空阴极电弧离子镀技术分别在4Cr5MoSiV1(H13)模具钢、Cr18Ni9Ti(304)不锈钢、YG6硬质合金、Ti6Al4V(TC4)钛合金4种基体表面沉积TiN薄膜。利用扫描电镜(SEM)对薄膜表面液滴进行观察分析,通过划痕仪对薄膜的膜/基结合力进行表征。结果表明:基体材料不同,TiN薄膜上液滴的密度、尺寸存在明显的区别。其中,镀膜后H13钢和304不锈钢表面的液滴数量最多,YG6硬质合金次之,TC4钛合金最少;薄膜的膜/基结合强度依次为YG6硬质合金>H13钢>304不锈钢>TC4钛合金。

精细TiN陶瓷薄膜的抗拉强度和界面结合强度

采用声发射监测悬臂梁弯曲实验法测量并计算出HCD离子镀法制备的精细TiN陶瓷薄膜的抗拉强度,及其与钛基材界面抗剪切强度(结合强度)值分别是:603MPa,242MPa。

PVD TiN涂层力学性能的测试方法

至今一种试样只能测试一到两个涂层性能参数,尚未得到一种切实可行、简单有效、物理意义明确的涂层力学性能的评价方法。文中通过对传统的复合板模型进行改进,提出一种能同时测试涂层多个力学性能参数的方法。利用应变仪、光学显微镜及拉伸机的有效组合,对W6Mo5Cr4V2钢PVD(physical vapor deposition,离子镀)涂覆TiN涂层的板状拉伸试样进行试验,得到TiN涂层的弹性模量、泊松比、剪切模量和断裂强度。弹性常数与文献报道基本吻合,而断裂强度差别较大,并分析差别的可能原因。

PCVD TiN膜的界面制备及性能

用TiCl4作为反应气体制备PCVDTiN镀层，对降低界面的氧含量，改善PCVDTiN镀层的界面性能进行了研究。在镀层制备过程中增加了界面制备过程，即采用氩离子轰击以及氢的反应使界面的氯含量降低，膜基界面得到改善。结果表明，与常规PCVD制备的TiN镀层相比，膜层的结合强度有大幅度的提高，耐磨性和耐蚀性均有改善，特别是其耐蚀性达到甚至超过奥氏体不锈钢的水平。

N_2流量对反应共溅射TiN/Ni纳米复合膜结构和结合强度的影响

以高纯Ti和Ni为靶材,在不同N_2气流量下反应磁控共溅射了TiN/Ni纳米复合膜,采用原子力显微镜、X射线衍射、X射线光电子能谱、场发射扫描电镜和划痕试验研究了N_2气流量对复合膜微结构、界面结合力和摩擦系数的影响。结果表明,共溅射TiN/Ni纳米复合膜组织细小、表面光滑、致密。TiN为fcc结构,其择优取向为(111)面。随N_2气流量增加,复合膜孔隙率、晶粒尺寸和沉积速率均出现不同程度的下降;而膜表面粗糙度先减小后增大,界面结合力则先提高后下降。本实验条件下,在N_2气流量为16mL/min时所沉积的复合膜表面粗糙度最小、界面结合力最好,分别为2.75nm和44.6N,此时复合膜的摩擦系数最低,为0.14。

磁控溅射TiN界面结合强度的压痕法测试

在试验的基础上提出了测量 Ti N涂层界面结合强度的弹塑性赫兹接触应力经验修正公式 ,作为应用实例测量了不同基体表面粗糙度对磁控溅射沉积的 Ti N涂层界面结合强度的影响 .将测量结果与其它测量方法所得结果进行了比较 ,证明提出的方法切实可行 .

Properties of W/DLC/W-S-C composite films fabricated by magnetron sputtering

A kind of W/DLC/W-S-C composite film was fabricated by magnetron sputtering method.Effects of WSx content on the structure and the adhesion of the composite films were investigated.In addition,tribological behavior of the composite films was studied in the conditions of the ambient air and N2 gas atmosphere by ball-on-disk tester.The results indicate that the composite films show dense and amorphous microstructure.The WCx and WSx compounds are found in amorphous diamond like carbon matrix in the top layers of W-S-C.A proper WSx content is beneficial for improving the adhesion of the composite films.In air atmosphere,the composite films with high C content have better wear resistance and the friction coefficients range from 0.15 to 0.25.In N2 condition,high WSx content is benefit for the wear resistance and the friction coefficients of the composite films range from 0.03 to 0.1.

离子束流密度和基底温度对TiN纳米薄膜性能的影响

采用低能离子束辅助沉积技术在Si片上制备了TiN纳米薄膜。考察了离子束流密度和基底温度对薄膜性能的影响。研究表明:随着离子束流密度的增大,TiN薄膜的纳米硬度上升,膜基结合力变化不大,薄膜的耐磨性获得了很大改善;制膜时的基底温度升高,薄膜的硬度也会上升,但膜基结合力下降,摩擦系数增大,薄膜的耐磨性下降。

TiN涂层陶瓷刀具膜—基界面应力的试验研究

利用X射线衍射(XRD)应力分析仪测试了TiN薄膜涂层与Si3N4陶瓷刀具基体的界面残余应力状况,分析了成膜过程中应力形成的原因及对膜—基结合强度的影响。结果表明,TiN薄膜的残余应力为压应力,本征应力为张应力,应力的大小及分布对涂层刀具的硬度和膜—基结合强度有明显影响。

4Cr13不锈钢表面镀TiN薄膜组织结构及性能的研究

采用多弧离子镀技术在4Cr13不锈钢上沉积TiN薄膜,在其他参数不变的条件下,研究不同弧电流下薄膜的组织、结构及性能。利用扫描电子显微镜、X射线衍射仪、显微硬度计、划痕仪和往复式摩擦磨损仪分别对薄膜进行表面形貌观察,物相分析,以及表面硬度、结合力、耐磨性检测。实验结果表明:弧电流对薄膜的表面形貌有明显的影响,随着弧电流的增大,薄膜表面的液滴数目和尺寸逐步增大;薄膜的相结构主要由TiN相组成,在(111)面有较强的择优取向,且随着弧电流的增大,衍射峰强度略有增加;随着弧电流的增大,薄膜的硬度先增大后减小,硬度值最大为2897HV;随着弧电流的增大,薄膜的结合力先增大后减小,当弧电流为105A时,薄膜的结合力最大,为75N;随着弧电流的增大,薄膜的摩擦系数先减小后增大,当弧电流为105A时,薄膜的耐磨性最好。