• 제목, 요약, 키워드: Filler

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BRAZING CHARACTERISTICS BETWEEN CEMENTED CARBIDES AND STEEL USED BY AG-IN BRAZING FILLER

  • Nakamura, Mitsuru;Itoh, Eiji
    • Proceedings of the KWS Conference
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    • pp.551-554
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    • 2002
  • As a general rule, the brazing process between cemented carbides and steel used by Silver (Ag) type brazing filler. The composition of Ag type filler were used Ag-Cu-Zn-Cd type filler mainly. But, the demand of Cadmium (Cd)-free in Ag type filler was raised recently. The reason why Cd-free in Ag brazing filler were occupied to vaporize as a CdO$_2$ when brazing process, because of Cd element was almost low boiling point of all Ag type filler elements. And, CdO$_2$ was a very harmful element for the human body. This experiment was developed Cd-freeing on Ag type filler that was used Indium (In) instead of Cd element. In this experiment, there were changed from 0 to 5% In addition in Ag brazing filler and investigated to most effective percentage of Indium. As a result, the change of In addition instead of Cd, there was a very useful element and obtained same property only 3% In added specimens compared to Cd 19% added specimens. These specimens were obtained same or more deflective strength. In this case, there were obtained 70 MPa over strength and wide brazing temperature range 650-800 C. A factor of deflective strength were influenced by composition and the shape of $\beta$ phase and between $\beta$ phase and cemented carbides interface. Indium element presented as $\alpha$ phase and non-effective factor directly, but it's occupied to solid solution hardening as a phase. $\beta$ phase were composed 84-94% Cu-Ni-Zn elements mainly. Especially, the presence of Ni element in interface was a very important factor. Influence of condensed Ni element in interface layer was increased the ductility and strength of brazing layer. Therefore, these 3% In added Ag type filler were caused to obtain a high brazing strength.

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Effects of the Size and Distribution of Preflocculated GCC on the Physical Properties of Paper

  • Lee, Kyong-Ho;Lee, Hak-Lae;Youn, Hye-Jung
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • pp.85-90
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    • 2006
  • Increasing the filler content of sheet improves the optical properties and printability of paper and provides an opportunity for saving production cost through fiber replacement with relatively low-priced filler. But increasing the filler content tends to decrease the strength of paper and filler retention. It also tends to deteriorate drainage on the paper machine. To overcome these problems, preflocculation technology of fillers may be employed. Many research efforts have been made on the properties of preflocculated filler, namely prefloc, whose size and size distribution were influenced by polymer type and shear level. But there is much to be investigated about the effect of the prefloc characteristics on the physical properties of paper. To evaluate the effect cationic polymers on the size and size distribution of preflocculated GCC and their shear stability, cationic PAM and cationic starch were used. The influence of the preflocculation on filler retention and its surface distribution, and the changes of physical and optical properties of handsheets affected by the characteristics of preflocs were examined. Filler distribution on sheet surface was also analyzed by EPMA. Results showed that cationic PAM formed large preflocs at low dosage. Cationic starch was required to add 15 times as much as cationic PAM to obtain the preflocs with similar size. But preflocs formed with cationic starch was superior in shear stability to those formed with cationic PAM. Filler preflocculation technology could provide an opportunity of increasing filler content significantly without loss in tensile strength. And increased filler contents could compensate brightness loss which often accompanies filler preflocculation. When excessively large preflocs were used, however, brightness loss rather than the improvement in tensile strength was predominant. Therefore it is of great importance to produce preflocs with proper size and shear stability for maximizing the improvement of physical properties of papers.

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Moisture Absorption Properties of Liquid Type Epoxy Encapsulant with Nano-size Silica for Semiconductor Packaging Materials (나노크기 실리카를 사용한 반도체용 액상 에폭시 수지 성형재료의 흡습성질)

  • Kim, Whan-Gun
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.2
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    • pp.33-39
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    • 2010
  • The moisture absorption properties such as diffusion coefficient and moisture content ratio of liquid type epoxy resin systems with the filler were investigated. Bisphenol A type and Bisphenol F type epoxy resin, Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these liquid type epoxy encapsulant according to the change of filler size. The temperature of glass transition (Tg) of these epoxy resin systems was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these epoxy resin systems according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these systems were calculated in terms of modified Crank equation based on Ficks' law. An increase of Tg and diffusion coefficient with filler size in these systems can be observed, which are attributed to the increase of free volume with Tg. The change of maximum moisture absorption ratio according to the filler size and filler content cannot be observed; however, the diffusion coefficients of these systems decreased with filler content. The diffusion via free volume is dominant in the epoxy resin systems with low nano-sized filler content; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the liquid type epoxy encapsulant with high nano-sized filler content.

A Study on Asphalt Paving Filler Development from Industrial By-products and its Characteristics in Construction Site (산업부산물을 활용한 아스팔트 포장용 채움재 개발 및 현장시공 성능평가 연구)

  • Cho, Do-Young;Park, Keun-Bae;Woo, Yang-Yi;Moon, Bo-Kyung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.227-234
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    • 2016
  • In this study, asphalt paving filler, which satisfies the KS standards, were prepared from industrial by-products, such as fly ash generated from thermal power plants, cogeneration ash generated from cogeneration plants, and desulfurized gypsum generated from the flue-gas desulfurization process. The properties of the prepared mixed filler and the existing limestone filler were compared through laboratory tests for preparing asphalt mixture using each filler. In addition, asphalt pavement field tests were conducted using the limestone filler and mixed filler. The dynamic stability, Marshall stability, tensile strength ratio, saturation, porosity, and flow value of the asphalt mixtures used in the field test were evaluated, as was done in the laboratory test. The laboratory and field construction test results revealed outstanding tensile strength ratio, Marshall stability and dynamic stability when using the prepared filler than for the existing limestone filler. Through optimization of the mixing design, the possibility of developing fillers, which the characteristics of the existing limestone filler, was confirmed.

A Study on the Reinforcing Effects of Inorganic Filler Contained NR Vulcanizates with Temperature and Loading Variation. (무기충전제(無機充塡劑)를 변량배합(變量配合)한 천연(天然)고무 가황체(加黃體)의 온도변화(溫度變化)에 따른 보강성효과(補强性效果)의 연구(硏究))

  • Choi, Jae-Woon;Hong, Chung-Sug;Chun, Kyung-Soo
    • Elastomers and Composites
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    • v.22 no.4
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    • pp.293-304
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    • 1987
  • The purpose of this study is to examine the effect of rubber-filler attachments on inorganic filler contained NR vulcanizatic. The results of this study showed as follows. The reinforcing properties and damping values of the vulcanizates in the elastic region showed strong relation with the filler characteristics and temperture. The vulcanizates filled with nature-activated inorganic filler like silica had higer elastic modulus and damping values than the vulcanizates of nature-nonactivated inorganic filter. The reinforcing effects of differential filler loadings on NR raised the effects with temperature rise, but the damping values varied with the filler characteristics and temperature variations.

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Al5052 Welding by $CO_2$ Laser using Filler Wire (용접 와이어를 사용한 Al5052 $CO_2$ 레이저 용접)

  • 박기영;이경돈;김주관
    • Laser Solutions
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    • v.5 no.1
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    • pp.13-21
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    • 2002
  • Compared to conventional welding process, laser welding does not use additional filler wire generally. However, if laser welding uses the filler wire, the applicability of the method can be broaden. When laser welding uses the filler wire, it is possible to enhance gap bridging ability and to prevent cracking in weld pool by metallurgical control. In this study, we had optimal condition and experimented gap bridging capability for butt welding with 2㎜ Al5052 alloys using the filler wire feeder. As the experimental parameters, wire feed rate and wire diameter are considered and then the performance of wire feed is evaluated under various filler wire welding conditions.

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Studies on Properties with Different Filler and Content in Pb-free Sealing Frit for Electronic Devices

  • An, Yong-Tae;Choe, Byeong-Hyeon;Ji, Mi-Jeong;Jang, U-Seok;Lee, Jun-Ho;Hwang, Hae-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.181-181
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    • 2009
  • 전자부품용 Pb-free sealing frit의 열팽창계수를 기판에 matching 시키기 위하여 음의 열팽창계수를 가지고 있는 $\beta$-Eucryptite, $\beta$-Spodumene를 합성하여 filler로 첨가하였다. 합성된 filler는 저온소성용 유리프리트의 높은 열팽창계수를 조절하기 용이하고, 유리프리트와 복합화 하여 소성하면 낮은 열팽창계수로 인한 우수한 열충격 저항성을 갖는다. Filler로써 $\beta$-Eucryptite, $\beta$-Spodumene의 결정성을 향상시키기 위해 $1250^{\circ}C$에서 5 시간 동안 유지하는 합성공정을 3회 반복 진행한 후 XRD를 사용하여 결정성을 분석하였고, TMA를 이용하여 filler 첨가량에 따른 유리프리트의 열팽장계수의 변화를 측정하였다. 또한, filler 입도와 함량에 따른 melting 특성을 분석하기 위해 Pill test를 진행하였으며, soda-lime glass 기판과의 접합면을 SEM을 사용하여 관찰하였다.

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Viscosity of polymer melts reduced jointly by filler addition and LCP fibrillation

  • He, Jiasong
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.132-132
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    • 2006
  • Filler loading (fiber or particulate) usually increases the melt viscosity of polymers. In contrast, the addition of these fillers and fibrillation of thermotropic liquid crystalline polymer (LCP) jointly decreased the viscosity of polymer melts to lower than those of pure component polymers, filler-loaded or LCP-blended ones; and even decreased the viscosity with increasing filler loading. Termed as rheological hybrid effect, this phenomenon correlated well with the LCP fibrillation in these ternary systems. Research taking fillers of various shapes and sizes showed that the filler addition promoted the LCP fibrillation, depending upon thermodynamic and dynamic factors involved.

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The Effects of the Arc Pressure Variation on the Penetration by the filler Wire Feed Rate in Pulsed TIG Welding (펄스 TIG용접에서 필러 와이어 송급속도에 따른 아크압력 변동이 용입에 미치는 영향)

  • 조상명;김진우
    • Journal of Welding and Joining
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    • v.22 no.1
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    • pp.71-76
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    • 2004
  • In the standpoint of the arc pressure, the effects of the filler wire feed rate on the penetration was investigated in this study. The pure Ar gas was used as a shield gas and the parameters investigated were the welding current and the filler wire feed rate. By making the experiment on the arc pressure, we could know that the arc pressure was fluctuated as the depth-into-arc of the tungsten rod. Instead of the filler wire, the tungsten rod was supplied into the molten pool to make this experiment. Because the filler wire melted in arc and then we couldn't measure the arc pressure. So, the tungsten rod - the highest melting point - was used. According to the depth-into-arc of the tungsten rod, the arc pressure could be measured by using the manometer. It was proved that the arc pressure got higher as the wire feed rate was slow. It is reported the arc pressure is proportion to welding voltage and the square of welding current. But, in the filler wire TIG welding, we could blow that arc pressure was fluctuated as the depth-into-arc of filler wire was changed. We could measure the arc pressure by the variation of the filler wire feed rate and could verify that it affected bead shape and penetration.

Production of High Loaded Paper by Dual Flow Addition of Fillers (II) - Effect of Location of Starch Addition - (충전제 투입 위치 이원화에 의한 고충전지 제조 (II) - 전분 투입 위치의 영향 -)

  • Choi, Do-Chim;Won, Jong Myoung;Cho, Byoung-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.47 no.1
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    • pp.84-92
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    • 2015
  • Fillers have been used to improve the optical and printing properties and to reduce the production cost while increasing the filler content in paper causes adverse effects on paper strength. In the previous study, it was shown that the thick stock addition of filler can increase the filler content without significantly sacrificing paper strength. This study was carried out to elucidate the effect of the location of starch addition (before or after the filler addition) on handsheet properties and a papermaking process as a part of developing the thick stock loading technology. In addition, effects of dual flow addition of cationic starch were evaluated. It was found that paper strength was superior when cationic starch was added after the filler addition. No adverse effects on optical properties, formation and filler retention were observed. Drainage was a bit slower when starch was added after the filler addition, which shall be resolved with regulating other factors. Dual flow addition of cationic starch before and after filler addition did not show any special advantage.