• Journal of the Korean Society for Heat Treatment
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• v.4 no.1
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• pp.19-29
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• 1991

This study was to investigate the influence of the substrate hardness on the hardness and adhesion of TiN thin film deposited by R.F. PACVD. Although the substrate hardness changed, chemical composition, stoichiometry and structure of TiN thin film did not change. ISE index was 1.96-1.99 for the substrate and was 1.57-1.79 for TiN thin film. And ISE index of TiN thin film was inverse proportion to the substrate hardness. When the substrate hardness was low, TiN thin film had many cracks around the indentation. But as the substrate hardness increased, TiN thin film had a few cracks and the deformation was limited within indentation. In having measured the adhesion of TiN thin film by SAT, the critical load (Lc) generally increased as the substrate hardness decreased.

• Korean Journal of Materials Research
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• v.13 no.9
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• pp.606-612
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• 2003

Surface and mechanical properties of thin films with submicron thickness was characterized by nanoindentation with Berkovich and Vickers tips, and scanning probe microscopy. Nanoindention was made in a depth range of 15 to 200 nm from the surface by applying tiny force in a range from 150 to $9,000 \mu$N. Stiffness, contact area, hardness, and elastic modulus were determined from the force-displacement curve obtained. Reliability was first tested by using fused quartz, a standard sample. Elastic modulus and hardness values of fused quartz measured were the same as those reported in the literature within two percent of error. Mechanical properties of ITO thin film were characterized in a depth range of 15∼200nm. As indentation depth increased, elastic modulus and hardness decreased by substrate effect. Ion beam deposited DLC thin films were indented in a depth range of 40∼50 nm. The results showed that the DLC thin film using benzene and bias voltage 0∼-50 V has elastic modulus and hardness value of 132 and 18 GPa respectively. Pure DLC thin films showed roughnesses lower than 0.25 nm, but silicon-added DLC thin films showed much higher roughness values, and the wavy surface morphology.

• Tribology and Lubricants
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• v.36 no.6
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• pp.320-323
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• 2020

Thin film coatings are commonly exploited to minimize wear and optimize the frictional behavior of various precision mechanical systems. The enhancement of thin film durability is directly related to the performance maximization of the system. Therefore, a fine approach to analyze the thin film wear behavior is required. Archard's equation is a representative and well-developed law that defines the wear coefficient, which is the probability of creating wear particles. A ploughing model is a commonly used model to determine the friction force during the abrasive contact. The equations demonstrate that the friction force and wear coefficient are inversely proportional to the hardness of the material. In this study, Archard's equation and ploughing models are modified with an effective hardness to minimize the gap between the experimental and numerical results. It is noted that the effective hardness is the hardness variation with respect to the penetration depth owing to the substrate effect. The nanoindentation method is utilized to characterize the effective hardness of Cu film. The wear coefficient value considering the effective hardness is more than three times higher than that without considering the effective hardness. The friction force predicted with the effective hardness agreed better with the results obtained directly from the friction force detecting sensor. This outcome is expected to improve the accuracy of friction and wear amount predictions.

• Korean Journal of Materials Research
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• v.12 no.8
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• pp.669-675
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• 2002

CrN film coated by AIP method, improved the mechanical properties (Hardness, Roughness, wear and fatigue) of Ti-6Al-4V alloy. The properties were studied using GXRD, XPS, Hardness, Roughness, wear and fatigue testers. CrN thin film thickness was about 7.5$\mu\textrm{m}$ and grew with (111) orientation. Hardness of CrN thin film was very high (Hv 1390) and roughness of the surface layer was greatly improved (Ra=0.063$\mu\textrm{m}$) compared with matrix alloy (Ra=0.321$\mu\textrm{m}$). Such changes of hardness and roughness could be contributed to improving the wear resistance and fatigue life. Striation like pattern with dimples and voids, a typical fatigue fracture mode, was observed throughout the specimen.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.1
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• pp.16-20
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• 2021

In this study, we tried finding new materials to improve the stain resistance properties of polymer insulating materials. Using the filtered vacuum arc source (FVAS) with a graphite target source, DLC thin films were deposited on silicon and polymer insulator substrates depending on their thickness to confirm the surface properties, physical properties, and structural properties of the thin films. Subsequently, the possibility of using a DLC thin film as a protective coating material for polymer insulators was confirmed. DLC thin films manufactured in accordance with the thickness of various thin films exhibited a very smooth and uniform surface. As the thin film thickness increased, the surface roughness value decreased and the contact angle value increased. In addition, the elastic modulus and hardness of the DLC thin film slightly increased, and the maximum values of elastic modulus and hardness were 214.5 GPa and 19.8 GPa, respectively. In addition, the DLC thin film showed a very low leakage current value, thereby exhibiting electrical insulation properties.

• Journal of Sensor Science and Technology
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• v.16 no.4
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• pp.319-323
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• 2007

This paper describes the mechanical characteristics of poly 3C-SiC thin films grown on Si wafers with thermal oxide. In this work, the poly 3C-SiC thin film was deposited by APCVD method using only Ar carrier gas and single precursor HMDS at $1100^{\circ}C$. The elastic modulus and hardness of poly 3C-SiC thin films were measured using nanoindentation. Also, the roughness of surface was investigated by AFM. The resulting values of elastic modulus E, hardness H and the roughness of the poly 3C-SiC film are 305 GPa, 26 GPa and 49.35 nm respectively. The mechanical properties of the grown poly 3C-SiC film are better than bulk Si wafers. Therefore, the poly 3C-SiC thin film is suitable for abrasion, high frequency and MEMS applications.

• Transactions of Materials Processing
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• v.13 no.1
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• pp.59-64
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• 2004

Nano-scratch tests were performed on PMMA thin films spin-coated on a Si substrate using an atomic force microscopy (AFM) with loads ranging form 10nN to 100nN. At low loads, a ridge pattern was formed on the PMMA thin film surface. No wear particles were observed during the pattern-forming mild wear. At high loads, severe wear by plowing occurred, accompanied by wear particles. The film with the highest hardness showed the highest wear resistance. Friction force generated during the scratching was measured, which was closely related with surface deformation of the film. A simple empirical equation to deduce scratch hardness of the film from a linear fixed-distance scratch test was proposed, and scratching-speed dependency of the scratch hardness was displayed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.488-493
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• 2022

Generally, diamond-like carbon films (a-C:H, DLC) have been shown to have a low coefficient of friction, a high hardness and a low wear rate. Pd-doped C thin film was fabricated using a dual magnetron sputtering with two targets of graphite and palladium. Graphite target RF power was fixed and palladium target RF power was varied. The structural, physical, and surface properties of the deposited thin film were investigated, and the correlation among these properties was examined. The doping ratio of Pd increased as the RF power increased, and the surface roughness of the thin film decreased somewhat as the RF power increased. In addition, the hardness value of the thin film increased, and the adhesive strength was improved. It was confirmed that the value of the contact angle indicating the surface energy increases as the RF power increases. It was concluded that the increase in RF power contributed to the improvement of the physical properties of Pd-doped C thin film.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.743-750
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• 2023

Aluminum alloy is a material widely used in the aircraft industry. However, since it has relatively low hardness, strength and tribological properties, it is necessary to improve these properties. In this paper, a TiN thin film was coated on the surface of AL7075-T7351 using DC magnetron sputtering. The coating was performed by setting different deposition pressure, deposition time, and applied power. Then, the tribological properties of the thin film were investigated. As a result of the experiment, the hardness of the thin film was higher than that of the base material, and the specimen with the highest hardness had excellent friction coefficient, wear amount, and adhesive strength characteristics. Through this study, it was confirmed that the tribological characteristics of aluminum alloy can be improved by depositing thin films using DC magnetron sputtering.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.06a
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• pp.73-73
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• 2001

Boron-containing materials have several excellent properties, such as superlnardness, insulation and non-Rinear optical property. Recently, oxynitride compounds, such as Si(ON), Ti(ON), became the promising materials applied in diffusion barrier layer and solar cell. With the expectation of obtaining the hybrid property, we have firstly grown the BON thin film by radio frequency (R.F.) plasma enhanced metalorganic chemical vapm deposition (PEMOCVD) with 100 kHz frequency and trimethyl borate precursor. The plasma source gases used in this study were Ar and $H_2$, and two kinds of nhmgen source gases, $N_2$ and <$NH_3$, were also employed. The as-grown films were characterized by XPS, IR, SEM and Knoop microlhardness tester. The relationship between the films hardness and the growth rate indicated that the hardness of the film was dependent on several factors such as nitrogen source gas, substrate temperature and film thickness due to the variation of the composition and the structure of the film. Both nitrogen and carbon content could raise the film hardness, on which nitrogen content did stronger effect than carbon. The smooth morphology and continuous structure was benefit of obtaining high hardness. The maximum hardness of BON film was about 10 GPa.