• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.895-900
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• 2018

In this study, the electroless deposition of Co-B and Co-W-B alloy thin films was developed and the effect of B and W contents on the hardness of the alloy thin films were investigated. An amorphous Co alloy film was successfully formed by electroless deposition and the contents of B and W in the film were controlled by varying the concentrations of dimethylamine borane and sodium tungstate dihydrate, which were used as a reducing agent and W source, respectively. The hardness of the thin films increased as the contents of B and W were increased because B and W act as impurities suppressing the propagation of dislocation in a film. In addition, it was found that the content of B and W in the Co alloy films can be increased significantly when aeration is not performed. Finally, the hardness of Co-W-B alloy thin film was improved up to 8.9 (${\pm}0.3$) GPa.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.368-376
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• 2003

In this research, DLC thin films are produced as several hundred nm thickness by PE-CVD method. And then these thin films are estimated tribological characteristics to find out useful possibilities as a protecting film for high-quality function and life extension at MEMs by mechanical properties observation . These are measured thickness and residual stress of DLC coating. Compared after measuring friction coefficient, adhesion force, hardness, cohesive force of coating films. As results all test, we can decide several conclusions. First, friction coefficient decreased, as the load increased. otherwise, friction coefficient increased, as thickness of coating film increased under low load$(1\~50mN)$. Secod, adhesion force increased as thickness of coating films. Third, hardness of coating film is affected by substrate coating film when it is less than thickness of 300nm and it has general hardness of DLC coating film when it is more than thickness of 500nm. Fourth, cohesive force of coating film is complexly affected by hardness, adhesion force, residual stress, etc.

• Korean Journal of Materials Research
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• v.28 no.10
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• pp.595-600
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• 2018

This study investigates the microstructural properties of CoCrFeMnNi high entropy alloy (HEA) oxynitride thin film. The HEA oxynitride thin film is grown by the magnetron sputtering method using nitrogen and oxygen gases. The grown CoCrFeMnNi HEA film shows a microstructure with nanocrystalline regions of 5~20 nm in the amorphous region, which is confirmed by high-resolution transmission electron microscopy (HR-TEM). From the TEM electron diffraction pattern analysis crystal structure is determined to be a face centered cubic (FCC) structure with a lattice constant of 0.491 nm, which is larger than that of CoCrFeMnNi HEA. The HEA oxynitride film shows a single phase in which constituting elements are distributed homogeneously as confirmed by element mapping using a Cs-corrected scanning TEM (STEM). Mechanical properties of the CoCrFeMnNi HEA oxynitride thin film are addressed by a nano indentation method, and a hardness of 8.13 GPa and a Young's modulus of 157.3 GPa are obtained. The observed high hardness value is thought to be the result of hardening due to the nanocrystalline microstructure.

• Journal of Surface Science and Engineering
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• v.53 no.1
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• pp.36-42
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• 2020

In this study, two novel methods to measure the surface hardness of anodic oxide films on aluminum alloys are reported. The first method is to impregnate oil-based ink into pores in the anodic oxide film and then to clean the ink on the surface using ethanol, resulting in an impregnation of inks only inside of the pores in anodic oxide film. The second method is to coat the anodic oxide film surface with thin Au layer less than 0.1 ?. Both the ink-impregnating method and Au-coating method provided clear indentation marks on the anodic oxide film surface when it was indented using a pyramidal-diamond penetrator. Thus, Vickers hardness of anodic oxide films on aluminium alloy could be measured successfully and precisely from the anodic film surface. In addition, advantages and disadvantages of the ink-impregnating method and Au-coating method for the measurement of surface hardness of anodic oxide films are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.826-830
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• 2015

Transparent Ag nanowire conducting thin films with high surface hardness were fabricated by bar coating method. When coating speed was changed from 35 mm/sec to 50 mm/sec, the transmittance of coated glass increased from 65.3% to 80.8% in visible light range and the surface resistance was changed from $10.1{\Omega}/sq$ to $23.3{\Omega}/sq$. The surface hardness and adhesion of thin film were 5H and 5B.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1059-1060
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• 2011

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2001.11a
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• pp.37-37
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• 2001

TiN coatings were applied for VarIOUS application fields, because of a good wear-resistance and a high hardness. Typically, TiN thin films show the hardness of 25GPa and friction coefficient of 0.6. However, in many field, one is looking for a more improved tool which has low friction coefficient and high wear resistance. The main motivation of this study is to characterize the influence of copper dopant content on TiN thin films. Ti-Cu-N thin films were deposited onto D2 steel substrates by PVD processing with various magnetron current densities (Cu contents). In this work, we synthesized titanium nitride films similar with reported typical titanium nitride films and synthesized Ti-Cu-N thin films with the addition of elemental copper which is measured improved hardness more than pure TiN films with copper content variables. This films has preferred oriented films of (111) direction. In addition, It was found that there is a strong correlation between content of various metal and film characteristics such as preferred orientation, grain size, hardness and friction coefficient and so, in future study, improved mechanical properties of TiN films can be controlled by change in target current density. The Ti-Cu-N film will show apparent hardness improvement and mechanical properties enhancement, when doping element is added onto TiN thin films. Film structure, chemical composition, mechanical properties were investigated by means of X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy(EDS), wear resistance tester and nanohardness tester.

• Transactions on Electrical and Electronic Materials
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• v.8 no.3
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• pp.125-130
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• 2007

DLC coating on ceramics is very useful for manufacturing the materials with hardness and low friction. Adhesion of DLC thin film on ceramics, on the other hand, is usually very weak. Adhesion of DLC film depends on many parameters such as contamination and chemical bonding between thin film and substrate. In this study, adhesion of DLC film on ceramics was improved by the intermediate layer when the plasma immersion ion deposition (PIID) technique was applied. It is found that the chemical composition and the thickness of intermediate layer have significantly an effect on the adhesion of DLC thin film on $Al_2O_3$.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.188-192
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• 2013

Many studies have been conducted for preventing from diffusion between silicon wafer and metallic thin film due to a decrease of line-width and multi-layer thin film for miniaturization and high integration of semiconductor. This paper has focused on the nano-mechanical property of diffusion barrier which sample is prepared for various gas flow rate of nitrogen with tungsten (W) base from 2.5 to 10 sccm. The deposition rate, resistivity and crystallographic properties were measured by a ${\beta}$-ray back-scattering spectroscopy, 4-point probe and x-ray diffraction (XRD), respectively. We also has investigated the nano-mechanical property using the nano-indenter. As a result, the surface hardness of W-N thin film was increased rapidly from 10.07 to 15.55 GPa when the nitrogen gas flow was increased from 2.5 to 5 sccm. And the surface hardness of W-N thin film had 12.65 and 12.77 GPa at the nitrogen gas flow of 7.5 and 10 sccm respectively. These results were decreased by the comparison with the W-N thin film at nitrogen gas flow of 5 sccm. It was inferred that these severe changes were caused by the stoichiometric difference between the crystalline and amorphous state in W-N thin film. In addition, these results were caused by increased compressive stress.

• Journal of the Korean Society for Heat Treatment
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• v.33 no.1
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• pp.25-32
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• 2020

In this study, the tribology of laser patterned DLC thin film was studied. DLC thin films were coated by RF-PECVD to improve the durability of tungsten carbide (WC) materials. DLC thin films have high hardness and low friction characteristics. Dot and line patterning was processed on the surface of DLC thin film with femtosecond laser, and the coefficient of friction was improved. As a result of ball on disk abrasion test, the hardness and friction coefficient of DLC thin films were much better than that of WC material. The friction coefficient of DLC thin film with dot patterning and line patterning showed better results. The excellent performance of the laser patterned DLC coating is appeared to reduce the coefficient of friction due to the reduction of surface contact area.