• Title/Summary/Keyword: Brazing temperature

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The Wetting and Interfacial Reaction of Vacuum Brazed Joint between Diamond Grit(graphite) and Cu-13Sn-12Ti Filler Alloy (다이아몬드 grit(흑연) / Cu-13Sn-12Ti 삽입금속 진공 브레이징 접합체의 젖음성 및 계면반응)

  • Ham, Jong-Oh;Lee, Chi-Hwan
    • Journal of Welding and Joining
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    • v.28 no.3
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    • pp.49-58
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    • 2010
  • Various alloy system, such as Cu-Sn-Ti, Cu-Ag-Ti, and Ni-B-Cr-based alloy are used for the brazing of diamond grits. However, the problem of the adhesion strength between the diamond grits and the brazed alloy is presented. The adhesion strength between the diamond grits and the melting filler alloy is predicted by the contact angle, thereby, instead of diamond grit, the study on the wettability between the graphite and the brazing alloy has been indirectly executed. In this study, Cu-13Sn-12Ti filler alloy was manufactured, and the contact angles, the shear strengths and the interfacial area between the graphites (diamond grits) and braze matrix were investigated. The contact angle was decreased on increasing holding time and temperature. The results of shear strength of the graphite joints brazed filler alloys were observed that the joints applied Cu-13Sn-12Ti alloy at brazing temperature $940^{\circ}C$ was very sound condition indicating the shear tensile value of 23.8 MPa because of existing the widest carbide(TiC) reaction layers. The micrograph of wettability of the diamond grit brazed filler alloys were observed that the brazement applied Cu-13Sn-12Ti alloy at brazing temperature $990^{\circ}C$ was very sound condition because of existing a few TiC grains in the vicinity of the TiC layers.

A Characteristic of Microstructures in Bonding Interlayer of Brazed Titanium to Copper (브레이징한 Ti/Cu 접합계면부의 미세조직 특성)

  • 김우열;정병호;이성렬
    • Journal of Welding and Joining
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    • v.13 no.3
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    • pp.106-115
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    • 1995
  • To know the bonding phenomena of Ti/Cu brazed joint, a characteristic of microstructures in bonding interlayer of vacuum brazed pure Ti to Cu has been studied in the temperature range from 1088 to 1133K for various bonding times using Ag-28wt%Cu filler metal. Also intermediate phases formed in bonded interlayer and behavior of layer growth have been investigated. The obtained results in this study are as follows: 1) Liquid insert metal width at the each brazing temperature was proportional to the square root of brazing time, and it was considered that the liquid insert metal width was controlled by the diffusion rate process of primary .alpha.-Cu formed at the Ti side. 2) Intermediate phases formed near the Ti interface were .betha.-Ti and intermetallic compounds TiCu, Ti$_{2}$Cu, Ti$_{3}$Cu, and TiCu. 3) .betha.-Ti formed in Ti base metal durig brazing transformed to lamellar structure, .alpha.-Ti + Ti$_{2}$Cu. The structure came from the eutectoil decomposition reaction in cooling. And the width of .betha.-Ti layer was proportional to the square root of brazing time, and it was considered that the growth of .betha.-Ti layer was controlled by interdiffusion rate process in .betha.-Ti. 4) The layer growth of TiCu, Ti$_{3}$Cu$_{4}$ and TiCu, phases formed near the Ti interface was linerface was linearly proportional to the brazing time, and it was considered that the layer growth of these phases was controlled by the chemical reaction rate at the interface.

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Microstructure and Tensile Strength Property of Arc Brazed DP steel using Cu-Sn Insert Metal (Cu-Sn 삽입금속을 이용한 DP강의 아크 브레이징 접합부의 미세조직과 인장특성)

  • Cho, Wook-Je;Cho, Young-Ho;Yun, Jung-Gil;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.31 no.1
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    • pp.58-64
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    • 2013
  • The following results were obtained, microstructures and tensile properties in arc brazed joints of DP(dual phase) steel using Cu-5.3wt%Sn insert metal was investigated as function of brazing current. 1) The Fusion Zone was composed of ${\alpha}Fe+{\gamma}Cu$ and Cu23Sn2. The reason for the formation of these solid solutions. Despite, Fe & Cu were impossible to solid solution at room temperature. It's melting & reaction to something of insert metal & Base Metal (DP Steel) by Arc. Brazing Process has faster cooling rate then Cast Process, Supersaturated solid solution at room temperature. 2) The increase Hardness of Fusion Zone was directly proportional to the rise of welding current. Because, ${\alpha}Fe+{\gamma}Cu$ phase (higher hardness than the Cu23Sn2.(104.1Hv < 271.9Hv)) Volume fraction was Growth, due to increasing the amount of base metal melting by High current. 3) The results of tensile shear test by Brazing, All specimens happen to fracture in Fusion Zone. On the other hand, when Brazing Current increasing tend to rise tensile load. but it was very small, about 26-30% of the base metal. 4) The result of fracture analysis, The crack initiate at Triple Point for meet to Upper B.M/Under B.M/Fusion Zone. This Crack propagated to Fusion zone. So ruptured by tensile strength. The Reason to in the fusion zone fracture, Fusion zone by Brazing of hardness (strength) was very lower then the base metal (DP steel). In addition the Fusion Zone's thickness in triple point was thin than the base metal's thickness in triple point.

Variations of micro-structures and mechanical properties of Ti/SUS321L joint using brazing method (브레이징을 이용한 Ti/SUS321L 접합체의 기계적 특성과 미세조직의 변화)

  • 구자명;정우주;한범석;정승부
    • Proceedings of the KWS Conference
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    • 2002.05a
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    • pp.285-287
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    • 2002
  • This study is investigated in variations of micro-structures and mechanical properties of Ti/SUS321L joint with bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed the thickness of their reaction layer increased. In tensile test, it was examined that the tensile strength had maximum value at the bonding time of 5min and decreased after bonding time over 5min because of increasing their oxides and intermetallic compounds.

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Variations of Micro-Structures and Mechanical Properties of Ti/STS321L Joint Using Brazing Method (브레이징을 이용한 Ti/STS321L 접합체의 미세조직과 기계적 특성의 변화)

  • 구자명;정우주;한범석;권상철;정승부
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.106-106
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    • 2002
  • This study investigated variations of micro-structures and mechanical properties of Ti / STS321L joint with various bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed that the thickness of their reaction layer increased due So increasing diffusion rate and time. From the EPMA results, Ti diffused to the STS321L substrate according to increasing bending time to 30min. Hardness of bonded interface increased with increasing bonding temperature and time due to increasing their oxides and intermetallic compounds. XRD data indicated that Ag, Ag-Ti intermetallic compounds, TiAg and Ti₃Ag and titanium oxide, TiO₂were formed in interface. In tensile test, it was found that the tensile strength had a maximum value at the bonding temperature of 900℃ and time of 5min, and tensile strength decreased over bonding time of 5min. The critical thickness of intermetallic compounds was observed to about 30㎛, because of brittleness from their excessive intermetallic compounds and titanium oxide, and weakness from void.

Variations of Micro-Structures and Mechanical Properties of Ti/STS321L Joint Using Brazing Method (브레이징을 이용한 Ti/STS321L 접합체의 미세조직과 기계적 특성의 변화)

  • 구자명;정우주;한범석;권상철;정승부
    • Journal of Welding and Joining
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    • v.20 no.6
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    • pp.830-837
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    • 2002
  • This study investigated variations of micro-structures and mechanical properties of Ti / STS321L joint with various bonding temperature and time using brazing method. According to increasing bonding temperature and time, it was observed that the thickness of their reaction layer increased due So increasing diffusion rate and time. From the EPMA results, Ti diffused to the STS321L substrate according to increasing bending time to 30min. Hardness of bonded interface increased with increasing bonding temperature and time due to increasing their oxides and intermetallic compounds. XRD data indicated that Ag, Ag-Ti intermetallic compounds, TiAg and $Ti_3Ag$ and titanium oxide, $TiO_2$ were formed in interface. In tensile test, it was found that the tensile strength had a maximum value at the bonding temperature of $900^{\circ}C$ and time of 5min, and tensile strength decreased over bonding time of 5min. The critical thickness of intermetallic compounds was observed to about $30\mu\textrm{m}$, because of brittleness from their excessive intermetallic compounds and titanium oxide, and weakness from void.

Brazing Adhesion Properties of Ag Coated W-Ag Electric Contact on the Cu Substrate (Ag 코팅한 W-Ag 전기접점/Cu 모재간의 브레이징 접합 특성)

  • Kang Hyun-Goo;Kang Yun-Sung;Lee Jai-Sung
    • Journal of Powder Materials
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    • v.13 no.1 s.54
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    • pp.18-24
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    • 2006
  • The brazing adhesion properties of Ag coated W-Ag electric contact on the Cu substrate have been investigated in therms of microstructure, phase equilibrium and adhesion strength. Precoating of Ag layer ($3{\mu}m$ in thickness) on the $W-40\%Ag$ contact material was done by electro-plating method. Subsequently the brazing treatment was conducted by inserting BCuP-5 filler metal (Ag-Cu-P alloy) layer between Ag coated W-Ag and Cu substrate and annealing at $710^{\circ}C$ in $H_2$ atmosphere. The optimum brazing temperature of $710^{\circ}C$ was semi-empirically calculated on the basis of the Cu atomic diffusion profile in Ag layer of commercial electric contact produced by the same brazing process. As a mechanical test of the electric contact after brazing treatment the adhesion strength between the electric contact and Cu substrate was measured using Instron. The microstructure and phase equilibrium study revealed that the sound interlayer structure was formed by relatively low brazing treatment at $710^{\circ}C$. Thin Ag electro-plated layer precoated on the electric contact ($3{\mu}m$ in thickness) is thought to be enough for high adhesion strength arid sound microstructure in interface layer.

Brazing of TiAl and AISI4140 steel using an Ag-Cu-Ti insert metal (Ag-Cu-Ti삽입금속을 이용한 TiAl과 AISI4140 강의 브레이징)

  • 구자명;이원배;김명균;김대업;김영직;정승부
    • Proceedings of the KWS Conference
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    • 2004.05a
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    • pp.45-47
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    • 2004
  • We have investigated the microstructures and the mechanical properties of TiA1/Cerameti1721 (Ag-Cu-Ti insert metal)/AISI4140 joints at 800$^{\circ}C$ for 60 to 300s using induction brazing method. Two continuous reaction layers of AICuTi and AICu$_2$Ti were formed at the interface between the braze and TiAl, whose thickness increased with the brazing time. The braze consisted of Ag-rich, Ti-rich, CuTi and CuTi$_2$ phases. The maximum tensile strength achieved 296MPa, which was 71% of that of TiAl base metal, for the specimen bonded at 800$^{\circ}C$. Further increase of the brazing temperature and time resulted in constant deterioration of its bonding strength due to large amount of brittle IMC.

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Effect of Brazing Condition on Tensile Properties in Brazing Joints of Inconel-625/Ni-201 Using MBF-30 (MBF-30을 사용한 Inconel-625/Ni-201 브레이징 접합부의 인장성질에 미치는 접합조건의 영향)

  • Yu, Jeong-Woo;Park, Sang-Hyun;Kim, Chang-Su;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.30 no.6
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    • pp.106-112
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    • 2012
  • This study was carried out to investigate the effect of bonding temperature and holding time on microstructure and mechanical properties in brazing joints of Ni-base superalloy using MBF-30 (Ni-4.5Si-3.2B [wt.%]). The heating rate was $20^{\circ}C$/min to the bonding temperatures $1050^{\circ}C$, $1070^{\circ}C$, $1090^{\circ}C$ under high vacuum condition. The holding times were 100s, 400s, 900s and 1600s. $Ni_3B$ phases and proeutectic Ni were observed in the interlayer of Ni-201. Then, Ni3B and Ni3Si were found in the middle region of brazing joint. Cr-boride phase appeared in the interlayer of Inconel-625. Tensile strength and elongation were decreased at $1050^{\circ}C$-1600s, $1070^{\circ}C$-900s and $1090^{\circ}C$-400s. After observation the fracture specimens, There was Ni3B which is very brittle phase in the grain boundary of Ni201.

A Study on the Zircaloy-4 Brazing with Beryllium Filler Metal for the Nuclear Fuel (베릴륨 용가재를 사용한 핵연료피복재 지르칼로이-4 브레이징에 대한 연구)

  • 고진현;김형수
    • Journal of Welding and Joining
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    • v.11 no.4
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    • pp.70-78
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    • 1993
  • An attempt was made to investigate the effect of brazing time on microstructure, microhardness, and corrosion of Zircaloy -4as well as the beryllium diffusion into its sheet. The sheets were coated with beryllium and brazed at $1020^{\circ}C$ for 20-40 minutes in $2{\times}10^{-5}$ torr vacuum atmosphere. 1. Microstructurally the brazed zone was largely divided into three regions: a region of continuous or partially formed of eutectic liquid films along grain boundaries; a region of precipitation in both grains and grain boundaries; a region of elongated wide structure of .alpha.-laths, which was not affected by beryllium. 2. Due to the precipitates, the beryllium-migrated region was hardened and the width of the hardened region increased with increasing brazing time. 3. Beryllium brazed Zircaloy -4 sheets showed a higher corrosion rate than those of as-received and heat-treated at a brazing temperature. 4. Diffusion coefficient of beryllium into Zircaloy -4 at $1020^{\circ}C$ for 30 minutes was $7.67{\times}10^{-7}cm^2/sec.$ It seemed that Be penetrated Zircaloy -4 by forming eutectic liquid films along grain boundaries in the proximity of Be/Zr interface and it, thereafter, diffused into Zircaloy mainly by interstitial solid solution.

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