On the Robustness of Scratch Testing for Thin Films: the Issue of Tip Geometry for Critical Load Measurement

1999 ◽  
Vol 594 ◽  
Author(s):  
Vincent D. Jardret ◽  
Warren C. Oliver
Keyword(s):  
Thin Films ◽  
Critical Load ◽  
Abrasive Particle ◽  
Great Influence ◽  
Polymer Coatings ◽  
Polymer Surfaces ◽  
Industrial Environment ◽  
Load Measurement ◽  
Abrasion Testing ◽  
Indenter Geometry

AbstractScratch and abrasion resistance of hard protective thin films and polymer coatings is often related to their ability to withstand abrasive conditions without fracturing. Wear particles generate catastrophic and severe wear for hard films, and fractured scratches are often very visible on shiny polymer surfaces. Using a particular abrasive particle shape, the fracture resistance of a surface can be characterized by the load required to create fracture damages. The scratch technique has demonstrated its ability to create these damage mechanisms and characterize the critical load for coatings failure. However, this technique does not yet have the reproducibility and robustness required to be implemented in an industrial environment. The major reason for this lack of robustness is the great influence of the indenter geometry on critical load results and the non-reproducibility of the geometry of conical indenters. This paper addresses this issue and presents a fast and robust method to characterize the indenter geometry based on the indentation technique. Indenters, with radii smaller than 1 micron, were used to characterize thin films of different nature and thickness. The influence of tip geometry on the critical load results is presented for paint coatings. The reproducibility of the critical load measurement using different indenter tips of identical geometry, as shown in this paper, represents a considerable technological breakthrough in abrasion testing and demonstrates the scratch test's ability to control the manufacturing quality of thin films in an industrial environment.

Characterisation of ‘wet’ polymer surfaces for tissue engineering applications: Are flat surfaces a suitable model for complex structures?

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Laleh Safinia ◽  
Jonny J. Blaker ◽  
Véronique Maquet ◽  
Aldo R. Boccaccini ◽  
Athanassios Mantalaris ◽  
...  
Keyword(s):  
Thin Films ◽  
Tissue Engineering ◽  
Pore Wall ◽  
Polymer Surfaces ◽  
Suitable Model ◽  
Tissue Engineering Scaffolds ◽  
3D Structures ◽  
Flat Surfaces ◽  
Point Test ◽  
Highly Porous

AbstractTissue engineering scaffolds are 3D constructs that simulate the growth environment in vivo. The present work aims to address the question of whether thin films, i.e., flat surfaces, are a suitable model for more complex 3D structures? With this in mind a complete study of the morphology and surface chemistry of poly(D,Llactide) (PDLLA) substrates, fabricated into two different structures, is presented. The polymer structures studied include a 3D, porous, foam-like scaffold prepared by the thermally induced phase separation (TIPS) method and flat polymer thin films made by solvent casting. Based on the maximum bubble point test, a new method to assess the wettability of wet pore wall surfaces inside highly porous 3D structures was developed and tested. The maximum pore diameter determined using the maximum bubble point test for the total wetting liquids was confirmed through image analysis of scanning electron micrographs. The method allows the determination of the contact angle between the wet pore wall and a contacting liquid. The captive bubble method was employed to characterise the wettability of flat polymer films in contact with water. Both structures were further characterised using zeta- (ζ-) potential measurements to assess the surface chemistry of the polymer. The results demonstrate that PDLLA contains acidic functional groups and is hydrophobic. In order to evaluate the sensitivity of the test methods, the polymer surfaces were modified by protein adsorption using fibronectin and collagen. ζ-Potential and wettability measurements show that proteins indeed adsorb on virgin PDLLA surfaces. Protein adsorption causes the wettability of the PDLLA for water to improve. Our results strongly indicate that flat surfaces are not a suitable model for surfaces in complex 3D structures such as highly porous tissue engineering scaffolds. Such scaffolds must be characterised as a 3D system.

Structure Characteristics of TiO2 Thin Films Prepared by DC Reactive Magnetron Sputtering at Low Pressure

2021 ◽  
Vol 19 (4) ◽  
pp. 77-86
Author(s):  
A.S. Ahmed ◽  
I.H. Kadim ◽  
A.A. Ramadhan
Keyword(s):  
Thin Films ◽  
Total Pressure ◽  
Great Influence ◽  
Dissociative Adsorption ◽  
Interplanar Distance ◽  
Main Role ◽  
Tio2 Thin Films ◽  
Two Phase ◽  
Adsorption Of Water ◽  
Standard Value

Structural properties of TiO2 thin films play a main role in determine the characteristic of the thin films especially their stability and activity, the total pressure has a great influence in determine the crystallinity of the films and the orientation of the facets of their structure, especially the two facet (101) and (001), the enhancing the structure properties will cause to enhance the application efficiency of TiO2 thin films such as the dissociative adsorption of water and the solar cell. Many researcher interest to prepare the TiO2 thin film under the low range of total pressure (less than to 10 Pa) to avoid the low degree of crystalline and the mixed of two phase anatas and rutile, so in our work tend to prepare TiO2 thin films under a high total pressure (more than 10 Pa) with values (10, 20, 50 and 100) Pa and with (1:1) mixed ratio of Argon and Oxygen gases, the pattern of X-Ray diffraction revealed that the structure was polycrystalline and the phase was anatas. The intensity at 2θ ≈ 25.00°, 37.00°, 53.00° and 55.00° correspond to the diffraction from (101), (004), (105) and (211) planes respectively. The intensity and number of peaks decreased with increased the total pressure, the plane (101) could be considered as a prefential growth plane which take a high texture factor and this would decreased with increased the total pressure, the ratio of texture factor between 001 and 101 will increase with decrease the total pressure, The lattice constant and the interplanar distance displayed a greater deviation compared with the standard value at the lowest total pressure than the decrease observed with increased total pressure.

scholarly journals Scratch-Profiles Study in Thin Films Using SEM and EDS

1984 ◽  
Vol 11 (3) ◽  
pp. 237-241 ◽  
Author(s):  
M. El-Shabasy ◽  
L. Pogány ◽  
G. Konczos ◽  
E. Hajtó ◽  
B. Szikora
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Critical Load ◽  
Conventional Method ◽  
Experimental Work ◽  
Measuring Method ◽  
Shearing Stress ◽  
Line Profiles ◽  
X Ray ◽  
Thickness Profile

The adhesion of evaporated or sputtered thin films to substrates is one of the most important characterising parameters in their fabrication. It is a conventional method to scratch the films using a stylus and evaluate the shearing stress, which is proportional to the energy of adhesion. For the evaluation it is necessary to determine the so-called critical load and the profile of the scratch.The aim during this experimental work was to find a method to evaluate the scratch profile from the X-ray-line profile and SEM pictures. From SEM pictures, the lateral dimensions and surface morphology of the scratches were studied. The thickness was also studied from X-ray-line profiles.In this paper the thickness profile measuring method and the conclusion for the scratch method are discussed.

Positronium Formation as a Probe of Polymer Surfaces and Thin Films

1995 ◽  
Vol 74 (24) ◽  
pp. 4947-4950 ◽  
Author(s):  
L. Xie ◽  
G. B. DeMaggio ◽  
W. E. Frieze ◽  
J. DeVries ◽  
D. W. Gidley ◽  
...  
Keyword(s):  
Thin Films ◽  
Polymer Surfaces ◽  
Positronium Formation

Crystallographic Texture of MgO and its Effect on the Growth of BaTiO3 Thin Films by RF Sputtering

2007 ◽  
Vol 546-549 ◽  
pp. 2175-2178
Author(s):  
Liang Qiao ◽  
Xiao Fang Bi
Keyword(s):  
Thin Films ◽  
Substrate Temperature ◽  
Crystallographic Texture ◽  
Great Influence ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
High Substrate Temperature ◽  
Argon Pressure ◽  
Structure And Microstructure ◽  
Deposition Conditions

In this work, MgO thin films were prepared by rf magnetron sputtering technique on two different substrates of Si (100) wafers and amorphous glasses. The influence of different deposition conditions such as substrate temperature, Ar pressure, film thicknesses on the crystal structure of MgO thin films were studied. BaTiO3 ferroelectric thin films were subsequently deposited on the MgO films. The XRD results showed that the orientation of MgO films was dependent greatly on the substrate temperature. A highly (100) oriented MgO thin films were obtained at the temperature of 800°C. The crystallographic texture has been deteriorated rapidly as the argon pressure decreased to 1.0 Pa. It has been also found that the film thickness has a great influence on the film orientation. High substrate temperature, high argon pressure and a certain thickness appear to be favorable for formation of a good texture for the MgO films. The structure and microstructure of the BaTiO3 films were various both with deposition conditions and with the crystallographic texture of the MgO. A highly (001) oriented ferroelectric BTO film was obtained on the MgO films with an optimized deposition conditions.

Preparation and Properties of Infrared Transparent Condutive Thin Films

2009 ◽  
Vol 1220 ◽  
Author(s):  
Yiding Wang ◽  
Li Li ◽  
Junjing Chen ◽  
Zhenyu Song ◽  
Yupeng An ◽  
...  
Keyword(s):  
Thin Films ◽  
Great Influence ◽  
Preparation Condition ◽  
Infrared Transmission ◽  
Electrically Conductive ◽  
X Ray ◽  
Atomic Force ◽  
Visible Transmittance ◽  
Ir Transmission ◽  
Conductive Thin Films

AbstractThis paper presents results for infrared transparent and conducting thin films based on In2O3. The films have been prepared by magnetrons sputtering equipment with different condition. Typical transmittance of 70%-80% with a film sheet resistance of 80-300Ω/□ in the 3.5-5.0μrn region has been achieved.Optically transparent and electrically conductive semiconductor Oxide films have been extensively studied in recent years. Such films have been prepared by various methods. In general, these films have high visible transmittance, but are opaque in the IR wavelength range of 1-12μm IR transmission. The infrared transparent and electrically conductive thin films are useful in certain important applications. For example, these films can be use as antistatic coatings, and while permitting a reasonable transmission coefficient for IR. Another obvious application is to serve as the conducting electrode for various optical devices where good infrared transmission is important. So, it is important to research indium oxide base infrared (3-5 um) transparent conduction thin films.It has been developed that preparation condition influence on properties of thin films. Such as the sputtering time, and pressure, and power, and the substrate temperature, had great influence on the crystal structure, optical and electrical properties of In2O3-based thin films.The In2O3-based thin films obtained were characterized and analyzed by X-ray Diffractometer (XRD), Atomic Force Microscope (AFM), Vander Pauw Method and Fourier Transform Infrared Spectroscopy (FTIR).

Novel optical techniques for the analysis of polymer surfaces and thin films

1991 ◽  
Vol 341 (3-4) ◽  
pp. 272-278 ◽  
Author(s):  
W. Knoll ◽  
W. Hickel ◽  
M. Sawodny ◽  
J. Stumpe ◽  
H. Knobloch
Keyword(s):  
Thin Films ◽  
Polymer Surfaces ◽  
Optical Techniques

scholarly journals Thin-film morphologies of block copolymers with nanoparticles

2015 ◽  
Vol 30 (S1) ◽  
pp. S16-S24 ◽  
Author(s):  
Dieter Jehnichen ◽  
Doris Pospiech ◽  
Peter Friedel ◽  
Guping He ◽  
Alessandro Sepe ◽  
...  
Keyword(s):  
Thin Films ◽  
Diblock Copolymers ◽  
Grazing Incidence ◽  
Polymer Surfaces ◽  
Nanostructured Surfaces ◽  
Force Microscopy ◽  
Molar Ratios ◽  
X Ray Scattering ◽  
Atomic Force

Diblock copolymers (BCPs) show phase separation on mesoscopic length scales and form ordered morphologies in both bulk and thin films, the latter resulting in nanostructured surfaces. Morphologies in thin films are strongly influenced by film parameters, the ratio of film thickness and bulk domain spacing. Laterally structured polymer surfaces may serve as templates for controlled assembly of nanoparticles (NPs). We investigated the BCP of poly(n-pentyl methacrylate) and poly(methyl methacrylate) which show bulk morphologies of stacked lamellae or hexagonally packed cylinders. Thin films were investigated by atomic force microscopy and grazing-incidence small-angle X-ray scattering. For film thicknesses f well below dbulk, standing cylinder morphologies were observed in appropriate molar ratios, while film thicknesses around and larger than dbulk resulted in cylinders arranged parallel to surface. To alter and/or improve the morphology also in presence of different NPs (e.g., silica, gold), solvent vapour annealing (SVA) was applied. The BCP morphology usually remains unchanged but periodicities change depending on type and amount of incorporated NPs. It was found that silica clusters enlarge lateral distances of cylinders, whereas Au NPs reduce it. The effect of SVA is weak. The quality of morphology is slightly improved by SVA and lateral distances remain constant or are slightly reduced.

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