• 제목/요약/키워드: Surface modification

검색결과 1,099건 처리시간 0.224초

전기화학적 에칭을 이용한 스테인리스 스틸의 표면 개질 (Surface Modification Method of Stainless Steel using Electrochemical Etching)

  • 이찬;김준원
    • 한국정밀공학회지
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    • v.31 no.4
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    • pp.353-358
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    • 2014
  • This paper reports a simple, yet effective 1-step surface modification method for stainless steel. Electrochemical etching in dilute Aqua Regia forms hierarchical micro and nanoscale structure on the surface. The surface becomes highly hydrophobic (${\sim}150^{\circ}$) as a result of the etching in terms of static contact angle (CA). However the liquid drops easily pinned on the surface because of high contact angle hysteresis (CAH), which is called a "petal effect": The petal effect occur because of gap between surface microstructures, despite of intrinsic hydrophobicity of the base material. The pore size and period of surface structure can be controlled by applied voltage during the etching. This method can be applied to wide variety of industrial demand for surface modification, while maintaining the advantageous anti-corrosion property of stainless steel.

질소이온주입에 의한 알루미늄의 표면개질특성 (Surface Modification of Aluminum by Nitrogen ion Implantation)

  • 강혁진;안성훈;이재상;이재형;김경균
    • 한국정밀공학회지
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    • v.22 no.12
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    • pp.124-130
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    • 2005
  • The research on surface modification technology has been advanced to improve the properties of engineering materials. ion implantation is a novel surface modification technology to enhance the mechanical, chemical and electrical properties of substrate's surface using accelerated ions. In this research, nitrogen ions were implanted into aluminum substrates which would be used for mold of rubber materials. The composition of nitrogen ion implanted aluminum alloy and nitrogen ion distribution profile were analyzed by Auger Electron Spectroscopy (AES). To analyze the modified surface, properties such as hardness, friction coefficient, wear resistance, contact angle, and surface roughness were measured. Hardness of ion implanted specimens was higher than that of untreated specimens. Friction coefficient was reduced, and wear resistance was improved. From the experimental results, it can be expected that ion implantation of nitrogen enhances the surface properties of aluminum mold.

질소이온주입에 의한 금형용 알루미늄의 표면개질특성 (Surface modification of Aluminum for mold by nitrogen ion implantation)

  • 강혁진;안성훈;김경동;이재상;이재형
    • 한국정밀공학회:학술대회논문집
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    • pp.254-259
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    • 2004
  • The research on surface modification technology has been advanced to change the properties of engineering material. Ion implantation is a novel surface modification technology to enhance the mechanical, chemical and electronic properties of mechanical parts. In this research, nitrogen ions are implanted into aluminum for mold to improve endurance and life span. To analyze modification of surface properties, micro hardness, friction coefficient, wear resistance, contact angle, and surface roughness were measured. Hardness of ion implanted specimens was higher than untreated specimen and friction coefficient was also improved. In this experiment, it can be expected that nitrogen ion implantation can contribute to enhance the mechanical properties of material and ion implantation technology may also be applied to other materials.

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표면개질의 트라이볼로지 특성에 관한 연구(제1보) (A Study on the Tribological Characteristics of Surface Modification (The 1st))

  • 오성모;채왕석;이봉구;김동현
    • 한국정밀공학회지
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    • v.16 no.5
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    • pp.145-150
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    • 1999
  • We have studied on the tribological characteristics of surface modification by Arc Ion Implantation(AIP) coating method. Coating materials were deposited by the Titanium carbide(TiC) and Titanium nitride(TiN). An experimental process was established to determine the tribological characteristics of friction and wear behaviour with the variation of applied load, temperature and the time by the Falex friction and wear test machine. The results, It can be improved that when the surface modification of hard coatings(TiC, TiN) was deposited steel, the tribological characteristics become better. It is argued that improved because of excellence of the anti-wear, the extreme pressure properties and the heat stability.

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잔골재용 폐유리의 표면개질이 모르타르의 역학적 특성 및 알칼리 실리카 반응에 미치는 영향 (Effect of Surface Modification of Waste Glass for Fine Aggregate on the Mechanical Properties and Alkali Silica Reaction of Mortar)

  • 손민재;김규용;이상규;사수이;유하민;남정수
    • 한국건축시공학회:학술대회논문집
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    • pp.23-24
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    • 2020
  • In this study, effect of surface modification of waste glass for fine aggregates on the mechanical properties and alkali silica reaction of mortar was analyzed. As a result, it was confirmed that the incorporation of waste glass fine aggregate decreases the mechanical properties of the mortar and increase the alkali silica reaction expansion. On the other hand, the surface modification of the waste glass fine aggregate is effective in improving this problem. However, unlike green and brown waste glass, it is judged that an additional experiment to determine the cause is necessary for white waste glass where alkali silica reactive expansion occurs extremely.

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Nd:YAG 레이저를 이용한 PDMS 표면개질 (Surface Modification of Polydimethylsiloxane using Nd:YAG Laser)

  • 신성권;송현승;이천
    • 한국전기전자재료학회논문지
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    • v.19 no.2
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    • pp.181-184
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    • 2006
  • Nd:YAG($\lambda$=266 nm, pulse) laser beam was irradiated on the PDMS surface to improve its chemical reaction, wettability, adhesive property. The various surface modification methods of PDMS were already studied using oxygen plasma, ozone and corona discharge. The surface modification using laser has the advantage of the simple experiment that only directly irradiated laser beam on the PDMS surface in the air. After the laser treatment, the PDMS surface was investigated using a contact angle measuring instrument. The contact angle was decreased with a increase of the surface oxygen content. In conclusion, the wettability of PDMS surface was improved by the laser treatment without changing of its bulk characteristics.

알칼리 표면개질을 통한 메조포러스 알루미늄 하이드록사이드 필름 형성 기구 (Formation Mechanism of Mesoporous Aluminum Hydroxide Film by Alkali Surface Modification)

  • 서영익;전용진;이영중;김대건;이규환;김영도
    • 한국재료학회지
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    • v.20 no.2
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    • pp.97-103
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    • 2010
  • In this study, a new, relatively simple fabrication method for forming a mesoporous $Al(OH)_3$ film on Al substrates was demonstrated. This method, i.e., alkali surface modification, was simply comprised of dipping the substrate in a $5\times10^{-3}$ M NaOH solution at $80^{\circ}C$ for one minute and then immersing it in boiling water for 30 minutes. After alkali surface modification, a mesoporous $Al(OH)_3$ film was formed on the Al substrate, and its chemical state and crystal structure were confirmed by XPS and TEM. According to the results of the XPS analysis, the flake-like morphology after the alkali surface modification was mainly composed of $Al(OH)_3$, with a small amount of $Al_2O_3$. The mesoporous $Al(OH)_3$ layer was composed of three regions: an amorphousrich region, a region of mixed amorphous and crystal domains, and a crystalline-rich region near the $Al(OH)_3$ layer surface. It was confirmed that the stabilization process in the alkali surface modification strongly influenced the crystallization of the mesoporous $Al(OH)_3$ layer.

졸-겔 공정으로 합성된 코디어라이트를 이용하여 알루미나의 표면개질 (Surface Modification of Alumina Ceramic with Mg2Al4Si5O18 Glass by a Sol-Gel Process)

  • 최필규;추민철;배동식
    • 한국재료학회지
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    • v.24 no.1
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    • pp.48-52
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    • 2014
  • The Mg-enriched magnesium aluminum silicate (MAS) glass is known for its higher mechanical strength and chemical resistance. Among such glasses, cordierite ($Mg_2Al_4Si_5O_{18}$) is well known to have a low thermal expansion and low melting point. Polycrystalline engineering ceramics such as alumina can be strengthened by a surface modification with low thermal expansion materials. The present study involves the synthesis of cordierite by a sol-gel process and investigates the effect of glass penetration on the surface of alumina. The cordierite powders were prepared from $Al(OC_3H_7)_3$, $Mg(OC_2H_5)_2$ and tetraethyl orthosilicate by hydrolysis and condensation reaction. The cordierite powders were characterized by X-ray diffraction (XRD, Rigaku), scanning electron microscope (SEM, JEOL: JSM-5610), energy dispersive spectroscopy (EDS, JEOL: JSM-5610), and universal testing machine (UTM, INSTRON). The X-ray diffraction patterns showed that the synthesized particles were ${\mu}$-cordierite calcined at $1100^{\circ}C$ for 1 h. The shape of synthesized cordierite was changed from ${\mu}$-cordierite to ${\alpha}$-cordierite with increasing calcination temperature. Synthesized cordierite was used for surface modification of alumina. Cordierite powders penetrated deeply into the alumina sample along grain boundaries with increasing temperature. The results of surface modification tests showed that the strength of the prepared alumina sample increased after surface modification. The strength of a surface modified with synthesized cordierite increased the most, to about 134.6MPa.