• Title/Summary/Keyword: base-metal

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Base Metal's Price Hike and Chinese Economic Growth (Base Metal 가격상승과 중국의 경제성장)

  • Lee, Hyun-Bock
    • Economic and Environmental Geology
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    • v.43 no.5
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    • pp.523-528
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    • 2010
  • With the financial crisis from USA had negative impacts on the real economy, base metals price on LME was downward in 4 quarter of 2008. Following the deepest global downturn in recent history, economic growth solidified and broadened to advanced countries and simultaneously the price of base metal on LME showed a rising curve over 2009. There are three factors supported an upward tendency of base metal's price. The First factor is the US economy recovery, the second factor is the weak dollar, the third factor is the chinese base metal demand. Among the factors, the last one is a major factor. Therefore, this study analyze the factor of the movement of price of base metal with linear regression analysis. The result of analysis show that the chinese GDP growth has effect on the recent upward base metal price. Despite the result, the upward movement is difficult to be sustained without the full recovery of advanced economies.

The Mixing Ratio Effect of Insert Metal Powder and Insert Brazing Powder on Microstructure of the Region Brazed on DS Ni Base Super Alloy (일방향응고 Ni기 초내열합금 천이액상화산접합부의 미세조직에 미치는 모재와 삽입금속 분말 혼합비의 영향)

  • Ye Chang-Ho;Lee Bong-Keun;Song Woo-Young;Oh In-Seok;Kang Chung-Yun
    • Journal of Welding and Joining
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    • v.23 no.6
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    • pp.99-105
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    • 2005
  • The mixing ratio effect of the GTD-111(base metal) powder and the GNI-3 (Ni-l4Cr-9.5Co-3.5Al-2.5B) powder on TLP(Transient Liquid Phase) bonding phenomena and mechanism was investigated. At the mixing ratio of the base metal powder under $50wt\%$, the base metal powders fully melted at the initial time and a large amount of the base metal near the bonded interlayer was dissolved by liquid inter metal. Liquid insert metal was eliminated by isothermal solidification which was controlled by the diffusion of B into the base metal. The solid phases in the bonded interlayer grew epitaxially from the base metal near the bonded interlayer inward the insert metal during the isothermal solidification. The number of grain boundaries farmed at the bonded interlayer corresponded with those of base metal. At the mixing ratio above $60wt\%$, the base metal powder melted only at the surface of the powder and the amount of the base metal dissolution was also less at the initial time. Nuclear of solids firmed not only from the base metal near the bonded interlayer but also from the remained base metal powder in the bonded interlayer. Finally, the polycrystal in the bonded interlayer was formed when the isothermal solidification finished. When the isothermal solidification was finished, the contents of the elements in the boned interlayer were approximately equal to those of the base metal. Cr-W borides and Cr-W-Ta-Ti borides formed in the base metal near the bonded interlayer. And these borides decreased with the increasing of holding time.

The Bonding Strength Characteristic of the Filler Metal Powder on the TLP Bonded Region of Superalloy GTD-111DS (일방향 초내열합금 GTD-111DS에서 삽입금속 분말에 따른 천이액상확산접합부의 접합강도 특성)

  • Oh, In-Seok;Kim, Gil-Moo;Moon, Byeong-Shik
    • Journal of Welding and Joining
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    • v.25 no.5
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    • pp.45-50
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    • 2007
  • The Ni-base superalloy GTD111 DS is used in the first stage blade of high power land-based gas turbines. Advanced repair technologies of the blade have been introduced to the gas turbine industry over recent years. The effect of the filler metal powder on Transient Liquid Phase bonding phenomenon and tensile mechanical properties was investigated on the GTD111 DS superalloy. At the filler metal powder N series, the base metal powders fully melted at the initial time and a large amount of the base metal near the bonded interlayer was dissolved by liquid inter metal. Liquid filler metal powder was eliminated by isothermal solidification which was controlled by the diffusion of B into the base metal. The solids in the bonded interlayer grew from the base metal near the bonded interlayer inward the insert metal during the isothermal solidification. The bond strength of N series filler metal powder was over 1000 MPa. and ${\gamma}'$ phase size of N series TLP bonded region was similar with base metal by influence of Ti, Al elements. At the insert metal powder M series, the Si element fluidity of the filler metal was good but microstructure irregularity on bonded region because of excessive Si element. Nuclear of solids formed not only from the base metal near the bonded interlayer but also from the remained filler metal powder in the bonded interlayer. When the isothermal solidification was finished, the content of the elements in the boned interlayer was approximately equal to that of the base metal. But boride and silicide formed in the base metal near the bonded interlayer. And these boride decreased with the increasing of holding time. The bond strength of M series filler metal powder was about 400 MPa.

The stiffness-degradation law of base metal after fatigue cracking in steel bridge deck

  • Liang Fang;Zhongqiu Fu;Bohai Ji;Xincheng Li
    • Steel and Composite Structures
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    • v.47 no.2
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    • pp.239-251
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    • 2023
  • The stiffness evaluation of cracked base metal is of great guidance to fatigue crack reinforcement. By carrying out fatigue tests and numerical simulation of typical cracking details in steel box girder, the strain-degradation law of cracked base metal was analyzed and the relationship between base metal stress and its displacement (stiffness) was explored. The feasibility of evaluating the stress of cracked base metal based on the stress field at the crack tip was verified. The results demonstrate that the stiffness of cracked base metal shows the fast-to-slow degradation trend with fatigue cracking and the base metal at 50mm or more behind the crack tip basically lose its bearing capacity. Drilling will further accelerate stiffness degradation with the increase of hole diameters. The base metal stress has a negative linear relation with its displacement (stiffness), The stress of cracked base metal is also related to stress intensity factor and its relative position (distance, included angle) to the crack tip, through which the local stiffness can be effectively evaluated. Since the stiffness is not uniformly distributed along the cracked base metal, the reinforcement patch is suggested to be designed according to the stiffness to avoid excessive reinforcement for the areas incompletely unloaded.

Study on Base metal Alloy (Base metal Alloy에 관한 고찰(考察))

  • Sung, Hwan-Kyung
    • Journal of Technologic Dentistry
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    • v.7 no.1
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    • pp.53-59
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    • 1985
  • This paper aims to examine baes metal alloy in all its aspects - the roles of elements, the content of every element according to uses, characters, laboratory technique methods and the kind of artificial base metal alloy registered in A.D.A. Specification. The results are as follows; 1. Base metal alloy is used widely bacaues it is rather cheap, but it should be handled appropriately in operating because its quality is bad. 2. Classifying base metal alloy, it is classified into Co-Cr alloy, Ni-Cr alloy, and Ni-Cr-Co alloy according to element, it is classified into partial denture alloy, surgical alloy and crown & bridge alloy according to use. 3. Among elements of base metal alloy, Bellium lowers the melting point of the alloy and increases the strength, but the amount should be limited when it is used because it destroys the organization of a living body. 4. The investments for base metal alloy are ethyl silcate bonded investment and phosphate bonded investment which endure well at high burn out temperature. 5. A.D.A specification No.14 in Kore contains Niranium, Nobilium, regalloy, Ticonium and Vitallium.

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Metal base of complete denture in edentulous patient (무치악 환자에서 총의치 금속상에 대한 고찰)

  • Koo, Cheol-Ihn;Lee, Heung-Tae;Park, Chan-Ik
    • Journal of Dental Rehabilitation and Applied Science
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    • v.18 no.3
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    • pp.197-204
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    • 2002
  • Polymers are the dominant material for fabrication of denture bases. However, resin base can't fufill the patients' satisfactions completely and solve the pronunciation problem and prevent the denture fracture. In spite of many advantages, metal denture bases do not widespread in clinical practice. The main reasons are the difficulties in fabrication and additional time and cost, inability to rebase such prostheses. The use of the metal base can be one of options in complete denture treatments. This study helps, through reveiwing previous reports and literature about the metal base, metal base to be useful in the clinical application by recommend the materials, indications and advantage/disadvantage of the metal base and introduce variable designs. The clinical application of the metal base have many advantages, but the dentists have to select cases carefully and apply designs according to patient's various conditions. In conclusion, the use of the metal base can't alternate treatment of inadequate conventional complete denture. Adequate complete denture is very important for the treatment of the metal base complete denture.

A Study on the Tensile Strength between Light-cured Relining Resin and Metal Denture Base (광중합형 이장재와 금속의치상 간의 결합력에 관한 연구)

  • Park, In-Chae;Lee, Joon-Kyu;Chung, Chae-Heon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.16 no.3
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    • pp.211-220
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    • 2000
  • The use of autopolymerizing-cured resin and light-cured resin for direct relining of complete and partial dentures has been popular. This investigation compared the adhesion of autopolymerizing-cured reline resin(Tokuso Rebase, Mild Rebaron) or light-cured reline resin(Mild Rebaron LC, Lighton-U) to metal base or resin base. Cylindrical samples were made from metal($Biosil^{(R)}$) or heat-cured resin(QC-20) and were prepared to produce a flat bonding surface. Cylindrical metal samples were roughened by scratch or by scratch and sandblast and were treated with primer(MR Bond) after scratch and sandblast. And then, liners were prossesed to the cylindrical metal or resin samples according to the manufacturer's recommendations so as to bond metal base or resin base. The specimens were tested in pure tension by using an Instron Univesal testing machine for the four direct reline resins. The results were as follows ; 1. In comparison with tensile bond strength of material relined on resin base or metal base, the case of resin base produced significantly higher tensile bond strength than the case of metal base. 2. Metal surface pretreatment or primer improved the tensile bond strength between the reline resin and the metal($Biosil^{(R)}$) base. 3. The tensile bond strength of Mild Rebaron LC relined on resin base or metal base were similar to those of the other reline resins.

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A Study on the Tensile Strength between Light-cured Relining Resin and Metal Denture Base (광중합형 이장재와 금속의치상 간의 결합력에 관한 연구)

  • Park, In-Chae;Lee, Joon-Kyu;Chung, Chae-Heon
    • Journal of Dental Rehabilitation and Applied Science
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    • v.16 no.2
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    • pp.161-170
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    • 2000
  • The use of autopolymerizing-cured resin and light-cured resin for direct relining of complete and partial dentures has been popular. This investigation compared the adhesion of autopolymerizing-cured reline resin(Tokuso Rebase, Mild Rebaron) or light-cured reline resin(Mild Rebaron LC, Lighton-U) to metal base or resin base. Cylindrical samples were made from metal($Biosil^{(R)}$) or heat-cured resin(QC-20) and were prepared to produce a flat bonding surface. Cylindrical metal samples were roughened by scratch or by scratch and sandblast and were treated with primer(MR Bond) after scratch and sandblast. And then, liners were prossesed to the cylindrical metal or resin samples according to the manufacturer's recomendations so as to bond metal base or resin base. The specimens were tested in pure tension by using an Instron Univasal testing machine for the four direct reline resins. The results were as follows ; 1. In comparison with tensile bond strength of material relined on resin base or metal base, the case of resin base produced significantly higher tensile bond strengths than the case of metal base. 2. Metal surface pretreatment or primer improved the tensile bond strength between the reline resin and the metal($Biosil^{(R)}$) base. 3. The tensile bond strengths of Mild Rebaron LC relined on resin base or metal base were similar to those of the other reline resins.

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Microstructure of the Brazed Joint for LRE Injector (액체로켓엔진용 인젝터 접합부의 미세조직)

  • 남대근;홍석호;이병호
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.87-89
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    • 2004
  • Brazing is an indispensable manufacturing technology for liquid rocket engine. In this study, for LRE injector, stainless steel 316L was used of base metal and Ni based MBF-20 of insert metal. The brazing and diffusion was carried out under various conditions. There are solid phase and. residual liquid phase in the brazed joint. With increment of holding time, the amount of solid phase increased and the elements of base metal and insert metal compositionally graded. Boron diffused from insert metal came into base metal and made boride with Cr and Mo at the brazed joint of base metal and insert metal.

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Dissolution Phenomenon of the Base Metal during TLP Bonding Using the Modified Base Metal Powder and Ni Base Filler Metal Powder (유사 조성의 모재분말과 Ni기 삽입금속 혼합분말을 사용한 천이액상확산 접합 시 모재의 용해현상)

  • Song, Woo-Young;Ye, Chang-Ho;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.25 no.3
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    • pp.64-71
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    • 2007
  • The dissolution phenomenon of the solid phase powder and base metal by liquid phase insert metal during Transient Liquid Phase bonding using the mixed powder composed of the modified GTD111(base metal) powder and the GNi3 (Ni-l4Cr-9.5Co-3.5Al-2.5B) powder was investigated. In case of the mixed powder contains modified GTD111 powder 50wt%, all of the powder was melted by liquid phase at 1423K. At the temperature between solidus and liquidus of GNi3, liquid phase penetrated into the boundary of the modified GTD111 powder and solid particle separated from powder was melted easily because area of reaction was increased. With increasing mixing ratio of the modified GTD111, it needed the higher temperature to melt all of the modified GTD111 powder. During Transient Liquid Phase bonding using the mixed powder composed of the modified GTD111 50wt% and GNi3 50wt% as insert metal, width of the bonded interlayer was increased with increasing bonding temperature by reaction of the base metal and liquid phase in insert metal. Dissolution of the base metal and modified powder by liquid phase progressed all together and after all of the powder was melted nearly, the dissolution of the base metal occurred quickly.