• 한국표면공학회지
• /
• 제29권5호
• /
• pp.478-481
• /
• 1996

Disproportionation reaction is very important and interesting reaction to be applied to such surface treatment as metal, alloy, compound coating, a surface etching and so on. In gaseous system, the reaction of Al chloride is applied to Al and Al alloy coating, and the similar reaction of Ti chloride is also used for Ti, Ti alloy and Ti compound coating. As for aqueous system, this reaction is utilized to such metal coat as Sn etc. and metal etching such as Cu, Fe and so on. Also in molten salts system, this reaction has many application for surface treatment like metal, alloy and compound coatings for corrosion, wear, heat resistance and so forth. For instance, carbide film, nitride film, boride film, alloy film, quite new different film from the components of substrate material are coated in single and multiple component film system by the disproportionation reaction.

• 열처리공학회지
• /
• 제2권2호
• /
• pp.68-83
• /
• 1989

Physical metallurgy aspects of gaseous ferritic nitrocarburising are reviewed in the light of basic studies undertaken since 1975 which have illustrated inconsistencies between the iron-carbon-nitrogen ternary phase diagram at $570^{\circ}C$ and the experimental observation of the co-existence of the ${\varepsilon}$ carbonitride phase and ferrite. Thermodynamic investigations by Xu and Li together with those by Slycke et al are reviewed to illustrate compatability between a modified isothermal section of the Fe-C-N system and the formation and growth of a monophased ${\varepsilon}$ structure under a variety of processing conditions. The implications of the modified diagram in terms of innovations in industrial ferritic nitrocarburising practice are discussed, together with limitations on the control of the process. The importance of the developing technology of black nitrocarburising for enhanced wear, fatigue, and corrosion resistance is emphasised. Basic studies and industrial status of austenitic nitrocarburising treatments are also reviewed, which highlight the importance of substrate strengthening for high load bearing applications of anti-scuff thermochemical treatments.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.621-624
• /
• 1999

Metalization technology of the fine patterns by electroless plating is required in place of electrodeposition as high-density printed boards(PCR) become indispensable with the miniaturization of electronic components. Electroless nickel plating is a suitable diffusion barrier between conductor meta1s, such as Al and Cu and solder is essetional in electronic packaging in order to sustain a long period of service. Moreover, Electroless nickel has particular characteristics including non-magnetic property, amorphous structure. wear resistance, corrosion protection and thermal stability In this study fundamental aspects of electroless nickel deposition were studied with effort of complexeing agents of different kinds. Then the property of electroless deposit are controlled by the composition of the deposition solution the deposition condition such as temperature and pH value and so on. the characteristics of the deposits has been carried out.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2001년도 춘계학술대회 논문집
• /
• pp.1101-1104
• /
• 2001

The special purposed materials, such as ceramics and stainless steel, are widely used in the various industrial area. They have properties of the higher strength of material, the wear-resistance, and the corrosion proof. But ceramics is a difficult-to-grind material which possesses the higher level of a strength and a brittleness. In this study, the theoretical investigation of a grinding force and of a surface roughness was conducted. The evaluations of grinding characteristics on the hardened-brittle and difficult-to-grind materials were experimentally carried out.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.42-47
• /
• 2004

Metallic glasses are amorphous meta-stable solids and are now being processed in bulk form suitable for structural applications including impact. Bulk metallic glasses have many unique mechanical properties such as high yield strength and fracture toughness, good corrosion and wear resistance that distinguish them from crystalline metals and alloys. However, only a few studies could be found mentioning the dynamic response and damage of metallic glasses under impact or shock loading. In this study, we employed a small explosive detonator for the dynamic indentation on a Zr-based bulk amorphous metal in order to evaluate the damage behavior of bulk amorphous metal under impact loading. These results were compared with those of spherical indentation under quasi-static and impact loading. The interface bonded specimens were adopted to observe the appearances of subsurface damage induced during indentation under different loading conditions.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.89-92
• /
• 2000

Laser claddmg 1s thc deposition of material on the surface of a part or workpiece. Cladding of metals produces a 100% dense metallurgically-bonded coating with minimal dilution for enhanced corrosion, abrasion and wear resistance. Despite of minimal heat Input and reduced processing time, cladding quality 1s affected by various process condition such as laser power and feed rate. Therefore, it is necessary to develop the momtoring and control methods of laser cladding process for the best cladding quality. In this paper, laser cladding monitoring system using CCD camera for measuring cladding pool shape, and photo-diode sensor for detecting optical signal emitted from the cladding front is introduced The variables extracted using this system can be apphed to control the laser cladding system to achieve the best claddmg results..

• 한국연소학회지
• /
• 제22권4호
• /
• pp.35-42
• /
• 2017

This case covers the issues related to the operation problem, cause analysis and improvement cases of the FGD that employed the non-leakage type GGH in coal-fired power plant for the first time in Korea. In the Cooler, there was a main problem that the tube is damaged by the ash cutting due to the high velocity of flue gas in the duct and by the weak wear resistance of material. In the Reheater, there was a main problem that the tube was corroded due to chlorine and sulfur in the circumstance of the low temperature. In order to solve those problems, we have improved the Reheater tube and tube fins by coating enamel to reduce corrosion rate.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 1996년도 특별강연 및 추계학술발표 개요집
• /
• pp.186-190
• /
• 1996

Laser cladding is a technique for modification on surface in materials. This study describes a laser cladding equipment design and the results of laser cladding nickel on rolled steel for general structure. The laser clsdding equipment designed to consider continuous supply, a fixed quantity. The material used MC plastic. Laser cladding condition is found out by processing parameters. The experiment advanced to suppy substrate with powder. The substrate is rolled steel for general structure(KS D 3503) and powder is using the nickel powder for the corrosion resitance, wear resistance and surface hardness of materials. When the substrate travel on X-Y table, laser beam irradiates to prevent from oxidize with shielding gas on it. The obtained specimens measure the victors hardness test. For the research laser cladding results make a comparative study the microstructure.

• 한국공작기계학회논문집
• /
• 제16권3호
• /
• pp.103-108
• /
• 2007

The number of parts made of ceramic materials has gradually been increasing in field of from mechanical engineering to electronics engineering and, mechanical engineering ceramics have spread because of three very favourable characteristic features of their application, namely, heat, wear, and corrosion resistance. therefore, the elaboration of suitable grinding technologies is Important. grinding is problematic because crack-free ceramics are difficult to process owing to their particular micro structure. In this paper we report on the application of advanced precision grinding process, elaborating continuous wheel dressing. The removal rate can be increased significantly and surface roughness is improved. Various problems(roughness, ground surface etc)encountered in grinding of ceramics are also discussed.

• 한국표면공학회지
• /
• 제43권6호
• /
• pp.260-265
• /
• 2010

STD 61 steel has been widely used for tools, metallic mold and die for press working because of its favorable mechanical properties such as high toughness, and creep strength as well as excellent oxidation resistance. The STD 61 tool steel coated with TiN and ZrN by sputtering results in improvement of wear and corrosion resistance. In this study, surface characteristics of TiN and ZrN film coated STD 61 by sputtering were studied by using FE-SEM, EDS, XRD, and XRR and nanoindentation tests. From the results of surface characteristics of coated specimen, the ZrN coated surface showed finer granular than that of TiN coated surface. The coated layer structures of ZrN and TiN were grown to (111) and (200) preferred orientation. From the results of XRR test for surface roughness, density and growth rate of coating film, surface roughness and growth rate of ZrN coated film revealed lower values those of TiN coated film, whereas density of ZrN coated film showed higher values than that of TiN coated film. From the nanohardness and elastic modulus test, nanohardness value and elastic modulus of ZrN coated film became higher than those of TiN coated film.