• Title/Summary/Keyword: hard Coating

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A Study on the Influence of Social Regulation on Competition and Innovation: A Case of Fire-retardant Coating Material for Steel Structure Sector in Korea (사회적 규제가 대체재 간 경쟁과 혁신에 미치는 영향에 관한 연구 : 국내 철강 구조물용 내화 피복재 산업의 사례연구)

  • Chang, Chul Kwon;Ji, Ilyong
    • Journal of Korea Technology Innovation Society
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    • v.20 no.4
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    • pp.939-969
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    • 2017
  • The interest in social regulation and its influence on innovation are increasing as the society concerns more for environment and safety. There have been plenty of literature about the impact of social regulation on innovation and its mechanism. Majority of research have been influenced by or based on the famous Porter's hypothesis. However, majority of the literature focus on internal factors such as expected benefits from change of regulations, and it is hard to find one studying social regulation's influence on innovation through external factors such as market or industrial structure. This study addresses this issue of the impact of social regulation on innovation by analyzing the case of fire-retardant coating material for steel structure industry in Korea. It scrutinizes the impact of social regulation which affects competition and innovation on substitute competing market, and tries to reveal that there might exist the other path to innovation, besides the way that the expected benefit from compliance of regulation directly drives innovation. As a result of the case study, we have found that changes in social regulation may act like economic regulation and restructure the market segment and this effect may lead to innovation. It can be explained by the fact that expected benefits from compliance of regulation can be a direct source of innovation, as Porter suggested, but the change of industry structure and competitive strength caused by the change in social regulation can also act as a driving force of innovation.

Fabrication of Superhydrophobic Aluminum Alloy Surface with Hierarchical Pore Nanostructure for Anti-Corrosion

  • Ji, Hyejeong;Jeong, Chanyoung
    • Corrosion Science and Technology
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    • v.18 no.6
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    • pp.228-231
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    • 2019
  • Aluminum and its alloys have been widely used in various fields because of low weight, high strength, good conductivity, and low price. It is well known that aluminum alloys that cause natural oxide film can inhibit corrosion in wet, salty environments. However, these oxides are so thin that corrosion occurs in a variety of environments. To prevent this problem, an electrochemical anodizing technique was applied to the aluminum alloy surface to form a thick layer of oxide and a unique oxide shape, such as a hierarchical pore structure simultaneously combining large and small pores. The shape of the structures was implemented using stepwise anodization voltages such as 40 V for mild anodizing and 80 V for hard anodizing, respectively. To maximize water repellency, it is crucial to the role of surface structures shape. And a hydrophobic thin film was coated by 1H, 1H, 2H, 2H-Perfluorodecyltrichlorosilane (FDTS) to minimize surface energy of the structure surface. Thus, such nanoengineered superhydrophobic surface exhibited a high water contact angle and excellent corrosion resistance such as low corrosion current density and inhibition efficiency.

Fabrication and Properties of Ni and Ni-W Electroplated Molds Using LIGA-like Process for Replication of Micro Components (LIGA-like 공정을 이용한 마이크로 부품 복제용 Ni과 Ni-W 금형 제조 및 특성)

  • Hwang, W.S.;Park, J.S.;Kang, Y.C.;Cho, J.W.;Park, S.S.;Lee, I.G.;Kang, S.G.
    • Korean Journal of Materials Research
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    • v.13 no.1
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    • pp.6-10
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    • 2003
  • Electroplated Ni and Ni-W micro-molds using LIGA-like process for replication of micro-components such as microfluidic parts and micro optical parts have been investigated. In general, it is hard to produce micro-parts using conventional mechanical processes. Micro-mold formed by LIGA-like process could fabricate micro-parts with high aspect ratio. In this paper, fabrication and properties of electroplated Ni molds with varying applied current types as well as those of Ni-W molds were investigated. Ni molds fabricated under pulse-reverse current showed the highest hardness value of about 160 Hv. Ni-W molds showed the hardness of about 500 Hv which was much harder than that of Ni electroplated molds. The above results suggested that high quality micro-molds could be fabricated by using Ni electroplating of pulse-reverse type for core molds and sequential Ni-W alloys coating.

Development of Automatic Painting Unit for Back-side of Longitudinal Stiffeners in Double Hull Blocks (선체블록 론지 이면부 자동 도장 장비 개발)

  • Kim, Eun-Tae;Lee, Dong-Hoon;Kim, Ho-Kyung
    • Special Issue of the Society of Naval Architects of Korea
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    • 2009.09a
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    • pp.123-129
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    • 2009
  • Ship painting procedures can be divided into two categories; Out-shell plate painting of the hull and the interior painting of each double gull blocks. It is really hard to apply standardized and automated operations to the latter because the double hull blocks contains a variety of complicated supportive materials and pipes to strengthen the ship structure. In addition their poor working conditions cause painting workers to avoid working in them, resulting in the waste of paints and additional pollution issues. So this research, successfully focused on overcoming the difficulties in working in the complicated blocks and the tough working conditions introduces the main details of automatic equipment systems and their transfer algorism which show how the equipment paints the inner sides of a longitudinal stiffener and moves to another automatically.

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High Temperature Oxidation Behavior of Plasma-sprayed Ti(Al,O)/$Al_2O_3$ Coatings on SS41 Steel (Ti(Al,O)/$Al_2O_3$ 플라즈마 코팅한 SS41의 고온산화 거동)

  • Choi, G.S.;Woo, K.D.;Lee, H.B.;Jeon, J.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.20 no.5
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    • pp.231-236
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    • 2007
  • High velocity oxy-fuel (HVOF) spraying was used to coat Ti(Al,O)/$Al_2O_3$ powder onto the SS41 steel plate. Macrostructure of the coated specimen has been investigated by scanning electron micrograph (SEM). High temperature oxidation behavior of the coated specimen and SS41 steel have been studied. From the results of SEM observation, Ti(Al,O)/$Al_2O_3$ powder was coated well onto the substrate SS41 steel. Porosity onto the coated layer was only 0.38%. The oxidation results showed that Ti(Al,O)/$Al_2O_3$ powder coated SS41 steel have improved little oxidation resistance at $900^{\circ}C$ in air, but improved remarkably oxidation resistance at $800^{\circ}C $ in air compare to the substrate SS41 steel.

A development of fabrication processes of microstructure using SU-8 PR (SU-8 PR을 이용한 마이크로 구조물 제작 공정 개발)

  • 김창교;장석원;노일호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.13 no.2
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    • pp.68-72
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    • 2003
  • In this paper, we developed a new thick photoresist fabrication technology for 3-dimensional microstructures. In general, like as AZ photoresist was coated with thin film thickness about 1 $\mu\textrm{m}$ to 30 $\mu\textrm{m}$, but photoresist like SU-8 has thickness of several tens $\mu\textrm{m}$ or more and high aspect ratio. When we fabricate a microstructure using the thick photoresist like SU-8, cracks on the SU-8 thick photoresist are appeared by stress which was caused by sudden cooling down during bake of the thick photoresist spun on wafer. Thus, it was hard to fabricate the microstructure using the thick photoresist for electroplating. In this paper, we developed a new process to produce a 3-dimensional microstructure without the crack by stress through a suitable thick photoresist coating, time control of cool down and time control of PEB (Post Expose Bake).

A Study on the Wear Characteristics of SiC Particle Dispersed Composites by Rheo-Compocasting Method (Rheo-compocasting법에 의한 SiC입자분산 복합재료의 마모특성에 관한 연구)

  • Kwak, Hyun-Man;Choi, Chang-Ock
    • Journal of Korea Foundry Society
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    • v.13 no.3
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    • pp.238-247
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    • 1993
  • Microstructure, hardness and wear characteristics of $SiC_p/Al-6.5wt%Si-1.7wt%Mg$ alloy composites fabricated by the method of rheo-compocasting and hot pressing are investigated in this study. The dispersion of SiC particles in the composites is homogeneous and the hardness improves as additional amount increases. The wear amount of the matrix metal increases highly as wear rates increase, for the wear mechanism changes from adhesive wear to melt wear, and the matrix metal was coated on the surface of revolving disc and its weight increases. In the 5vol% composites, Fe is adhered on the surface of specimen by the projection of the dispersed hard SiC particles which have net-work structure and the coating layer is about $300{\mu}m$. But in the composite more than 20vol%, the wear amount of composite decreases because the SiC particles which have superior hardness, wear resistance and heat resistance properties resist wear, the abrasive wear turn out predominant wear mechanism and so the wear amount of revolving disc increases.

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Characterizations of Ti-Al-V-N Films Deposited by DC and RF Reactive Magnetron Sputtering (직류 및 고주파 마그네트론 스퍼터링법으로 증착한 Ti-Al-V-N 박막의 특성)

  • Sohn, Yong-Un;Chung, In-Wha;Lee, Young-Ki
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.6
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    • pp.398-404
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    • 2000
  • The Ti-Al-V-N films have been deposited on various substrates by d.c and r.f reactive magnetron sputtering from a Ti-6Al-4V alloy target in mixed $Ar-N_2$ discharges. The films were investigated by means of XRD, AES, SEM/EDX, microhardness, TG and scratch test. The XRD and SEM results indicated that the films were of single B1 NaCl phase having dense columnar structure with the (111) preferred orientation. The composition of Ti-Al-V-N film was the Ti-7.1Al-4.3V-N(wt%) films. Adhesion and microhardness of Ti-Al-V-N films deposited by r.f magnetron sputtering method were better than those deposited by d.c magnetron sputtering method. The anti-oxidation properties of Ti-Al-V-N films were also superior to that of Ti-N film deposited by the same deposition conditions.

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A HISTOLOGICAL STUDY OF SURROUNDING BONE TISSUE REACTION TO HYDROXY APATITE COATED DENTAL IMPLANT (Hydroxy Apatite가 피복된 치과매식체의 주위골조직 반응에 관한 조직학적 연구)

  • Song, Joon-Ki;Hur, Sung-Joo;Cho, In-Ho
    • The Journal of Korean Academy of Prosthodontics
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    • v.29 no.2
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    • pp.23-34
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    • 1991
  • Even if we can recover the function of mastication, pronunciation and esthetic using the fixed or removable prosthesis in the loss of teeth or hard tissue in the oral cavity, we use several kinds of implants in order to solve the problem which can be occured when we can't install the denture because of excessive bone resolution or psychlogical affairs. At present Titanium implant plays a major role in this field and has osseointegrated. And the study on the modern material is going on, that result in developing and using the implant which is coated with HA, bone induced material. In this, I studied histologically the change of the bone tissue which is occured when three kinds of HA coated implants. Such as Integral, Sustain, Biovent implanted into mandible of dog and got a 8-weeks healing period. I got the conclusion as follows: 1. Most of the implant which is covered with serveral kinds of HA coating implant in bone after 8 weeks being implanted and has osseointegrated, partially converted into the connective tissue. 2. Biovent formed the connective tissue in the perforated area of inferior alveolar canal and has osseointegrated.

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A Study in the Heat Resistance Properties of STD61 Steel using the Surface Hardening Method (STD61 강의 내열특성향상을 위한 표면경화에 관한 연구)

  • Lee, Gu-Hyeon
    • 연구논문집
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    • s.26
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    • pp.121-132
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    • 1996
  • The carburising surface modification treatment of the die steel has been used for improving wear resistance and heat cycle strength of the die and preventing a pitting on the surface because the carbides are forming in the matrix during carburising. Generally, the hot forging die was used after quenching-tempering treatment or nitriding after quenching-tempering treatment. The nitriding after carburising on the surface of a hot die steel and a wear resistance die steels was suggested by SOUCHARD, JACQUOT. and BUVRON. This surface modification treatment improved the adhesive and abrasive wear resistance and friction coefficient. The process was introduced to the forging die of stainless steel, titanium alloy steel, alloy and medium carbon steel and the physical properties of the die after the treatment were improved. The surface hardening treatment of the nitriding, the carburising, the boriding, and TD process were used to improved the life time of the forging die. Also, the coating process of PVD, CVD and PCVD were used and the hard chromium plating was occasionally used. Therefore, this study analyzed the effects of the carburising time and the conditions of nitriding on STD61 steel. The case depth, the surface hardness, the forming carbide size and shape during overcarburising process on the die steel were also examined.

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