• Title/Summary/Keyword: SiC particle

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Mechanical Properties and Wear Performance of the Al7075 Composites Reinforced with Bimodal Sized SiC Particles (이종입자 강화 SiC/Al7075 금속복합재료의 압축특성 및 마모특성 연구)

  • Lee, Donghyun;Cho, Seungchan;Kim, Yangdo;Lee, Sang-Kwan;Lee, Sang-Bok;Jo, Ilguk
    • Composites Research
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    • v.30 no.5
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    • pp.310-315
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    • 2017
  • In this study, we have investigated microstructure, mechanical properties and wear characteristic of aluminum metal matrix composites with a high volume fraction and uniformly dispersed SiC particles which produced by a liquid pressing process. The volume fraction of bimodal SiC/Al7075 composite was 12% higher than that of the monomodal SiC/Al7075 composite and a compressive strength is increased about 200 MPa. As a result of the abrasion test, the wear width and depth of the bimodal SiC/Al7075 composite were $285.1{\mu}m$ and $0.45{\mu}m$, respectively. The coefficient of friction of bimodal SiC/Al7075 was 0.16.

Effects of Carbide Morphology and Heat Treatment on Abrasion Wear Resistance of Chromium White Cast Irons (합금크롬주철의 탄화물형상 및 열처리가 내마모성에 미치는 영향)

  • Yu, Sung-Kon;Matsubara, Yasuhiro
    • Korean Journal of Materials Research
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    • v.12 no.5
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    • pp.407-413
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    • 2002
  • Eutectic high chromium cast irons containing 17%Cr and 26%Cr were produced for this research by making each of them solidify unidirectionally. Abrasion wear test against SiC or $Al_2$O$_3$bonded paper was carried out using test pieces cut cross-sectionally at several distances from the chill face of castings. The wear resistance was evaluated in connection with the parameters such as eutectic colony size($E_w$), area fraction of boundary region of the colony($S_B$) where comparatively large massive chromium carbides are crystallized and, average diameter of chromium carbides in the boundary region($D_c$). The wear rate($R_w$), which is a gradient of straight line of wear loss versus testing time, was influenced by the type and the particle size of the abrasives. The $R_w$ value against SiC was found to be larger than that against A1$_2$O$_3$under the similar abrasive particle size. In the case of SiC, the $R_w$ value increased with an increase in the particle size. The $R_w$ value also increased as the eutectic colony size decreased, and that of the 17%Cr iron was larger than that of the 26%Cr iron at the same $E_w$ value. Both of the $S_B$ and $D_c$ values were closely related to the $R_w$ value regardless of chromium content of the specimens. The $R_w$ values of the annealed specimens were greater than those of the as-cast specimens because of softened matrix structures. As for the relationship between wear rate and macro-hardness of the specimens, the hardness resulting in the minimum wear rate was found to be at 550 HV30.

Preparation of ZrC/SiC by Carbothermal Reduction of Zircon (지르콘의 탄소열환원에 의한 ZrC/SiC의 합성)

  • Park, Hong-Chae;Lee, Yoon-Bok;Lee, Cheol-Gyu;Oh, Ki-Dong
    • Applied Chemistry for Engineering
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    • v.5 no.6
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    • pp.1044-1055
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    • 1994
  • The preparation of ZrC/SiC mixed powders from $ZrSiO_4/C$ and $ZrSiO_4/Al/C$ systems was attempted in the temperature range below $1600^{\circ}C$ under Ar or $Ar/H_2$ gas flow(100-500ml/min). The formation mechanism and kinetics of ZrC/SiC were suggested and the resultant powders were characterized. In $ZrSiO_4/C$ system, ZrC and SiC were formed by competitive reaction of $ZrO_2(s)$ and SiO(g) with carbon at temperature higher than $1400^{\circ}C$. The apparent activation energy for the formation of ZrC was approximately 18.5kcal/mol($1400-1600^{\circ}C$). In $ZrSiO_4/Al/C$ system, ZrC was formed by reaction of ZrO(g) with Al(l, g) and carbon at temperature higher than $1200^{\circ}C$, and SiC was formed by reduction-carbonization of SiO(g) with Al(l, g) and carbon at temperature higher than $1300^{\circ}C$. The products obtained at $1600^{\circ}C$ for 5h consisted of ZrC with lattice constant of $4.679{\AA}$ and crystallite size of $640{\AA}$, and SiC with lattice constant of $4.135{\AA}$ and crystallize size of $500{\AA}$. And also, the mean particle size was about $21.8{\mu}m$.

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Synthesis of β-SiC Powder using a Recycled Graphite Block as a Source (그라파이트 블록을 원료로써 재활용한 β-SiC 분말 합성)

  • Nguyen, Minh Dat;Bang, Jung Won;Kim, Soo-Ryoung;Kim, Younghee;Jung, Eunjin;Hwang, Kyu Hong;Kwon, Woo-Teck
    • Resources Recycling
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    • v.26 no.1
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    • pp.16-21
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    • 2017
  • This paper relates to the synthesis of a source powder for SiC crystal growth. ${\beta}-SiC$ powders are synthesized at high temperatures (>$1400^{\circ}C$) by a reaction between silicon powder and carbon powder. The reaction is carried out in a graphite crucible operating in a vacuum ambient (or Ar gas) over a period of time sufficient to cause the Si+C mixture to react and form poly-crystalline SiC powder. End-product characterizations are pursued with X-ray diffraction analysis, SEM/EDS, particle size analyzer and ICP-OES. The purity of the end-product was analyzed with the Korean Standard KS L 1612.

Synthesis of Si-CNT-C Composites and Their Application to Lithium Ion Battery (실리콘-탄소나노튜브-탄소 복합체 제조 및 리튬이온전지 응용)

  • Kim, Chan Mi;Kim, Sun Kyung;Chang, Hankwon;Kil, Dae sup;Jang, Hee Dong
    • Korean Chemical Engineering Research
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    • v.56 no.1
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    • pp.42-48
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    • 2018
  • Silicon has attracted extensive attention due to its high theoretical capacity, low discharge potential and non-toxicity as anode material for lithium ion batteries. In this study, Si-CNT-C composites were fabricated for use as a high-efficiency anode material in a lithium ion battery. Aerosol self-assembly and post-heat treatment processes were employed to fabricate the composites. The morphology of the Si-CNT-C composites was spherical and an average particle size was $2.72{\mu}m$. The size of the composite increased as concentration of Si and CNT increased in the precursor solution. In the Si-CNT-C composites, CNT and C carbonized from glucose were attached to the surface of Si particles. Electrochemical measurement showed that the cycle performance of Si-CNT-C composites was better than that of silicon particles.

Thermal Sprayed AlSiMg/TiC Composite Coatings : Fabrication of Powder and Characteristics of Coatings (I) (AlSiMg/TiC 복합 용사 피막 : 분말제조 및 피막 특성(I))

  • 양병모;변응선;박경채
    • Journal of Welding and Joining
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    • v.18 no.5
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    • pp.98-104
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    • 2000
  • Aluminum alloys are being employed in automobile parts as strive to reduce overall vehicle weight to meet demands for improved fuel economy and reduction in vehicle emissions. Al-based composites reinforced with ceramic ($Al_2O_3,\;SiC,\;TiC\;and\;B_4C$) applications in a variety of components in automotive engines, such as liners, where the tribological properties of the material are important. In this study, Al-base composites reinforced with TiC particle powders has been developed for producing plasma spray coatings. The composite plasma spray powders were prepared Al-13Si-3Mg(wt%) alloy with TiC(40, 60 and 80wt%) particles ($0.2~5{\mu}textrm{m}$) by drum type ball milling. The composite powders ($36~76{\mu}textrm{m}$) were sprayed with plasma torch. Plasma sprayed coatings were heat-treated at $500^{\circ}C$ for 3 hours. The wear resistances of the plasma sprayed coatings were found to decrease with increasing TiC content and improved with heat treatment. AlSiMg-40% TiC heat-treated coatings were showed the best wear resistance in this study.

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A Study on the Thermal Properties of Al-xSi-2Cu-1Mg/ySiC(x:6, 12, 18. $y:0{\sim}10wt.%$) Composite Materials (Al-xSi-2Cu-1Mg/ySiC(x:6, 12, 18. $y:0{\sim}10wt.%$)계 복합재료의 열적성질에 관한 연구)

  • Park, Sang-Joon;Jo, Won-Yong;Kang, Se-Seon;Lim, Yoon-Su;Kwon, Hyuk-Mu;Yoon, Eui-Park
    • Journal of Korea Foundry Society
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    • v.13 no.4
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    • pp.342-349
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    • 1993
  • The purpose of this study is to obtain basic information on the particle dispersion, the coefficient of thermal expansion and the thermal conductivity of compocasted Al-xSi-2Cu-1Mg/ySiC(x:6, 12, 18. $y:0{\sim}10wt.%$) composite. With increasing the content of SiC particles, the thermal expension coefficient and the thermal conductivity decrease. The coefficient of thermal expension between 20 and $300^{\circ}C$ is $21.3{\times}10^{-6}/^{\circ}C{\sim}18.0{\times}10^{-6}/^{\circ}C$ for the Al-Si alloys and $18.4{\times}10^{-6}/^{\circ}C{\sim}16.0{\times}10^{-6}/^{\circ}C$ for the composite with 10wt.% SiC. The thermal conductivity at $300^{\circ}C$ is $121{\sim}169W{\cdot}m^{-1}{\cdot}k^{-1}$ for the Al-Si alloys and $114{\sim}159W{\cdot}m^{-1}{\cdot}k^{-1}$ for the composite with 10wt.% SiC.

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R-Curve Behavior and Mechanical Properties of Al2O3 Composites Containing SiC and TiC Particles (SiC와 TiC 입자를 함유하는 Al2O3 입자복합체의 균열저항거동과 기계적 성질)

  • Na, Sang-Woong;Lee, Jae-Hyung
    • Journal of the Korean Ceramic Society
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    • v.39 no.4
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    • pp.413-419
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    • 2002
  • Particulate composites of $Al_2O_3$/TiC/SiC, $Al_2O_3$/TiC and $Al_2O_3$/SiC have been fabricated by hot pressing and their R-curve behaviors and mechanical properties were investigated. $Al_2O_3$ containing 30 vol% TiC particles showed higher toughness by 8% than that for monolithic alumina and its fracture strength was increased significantly by approximately 30%. On the other hand, the addition of 30 vol% SiC of $3{\mu}m$ in $Al_2O_3$ decreased the fracture strength slightly but induced a rising R-curve behavior owing to the strong crack bridging of SiC particles. In case of $Al_2O_3$/TiC/SiC, arising R-curve behavior was also observed and the fracture toughness reached 6.6 MPa${\cdot}\sqrt{m}$ at the crack length of $1000{\mu}m$, which was lower than that of $Al_2O_3$/SiC, however, while the fracture strength was higher by about 20%. The fracture toughness seemed to be decreased as smaller TiC particles roughened the SiC interface and pullout of the SiC particles for crack bridging became less active.

Annealing Effect on controlling Self-Organized Ag/Ti Nanoparticles on 4H-SiC Substrate (4H-SiC기판 위의 자기구조화된 Ag/Ti 나노입자 제어를 위한 열처리 분석)

  • Kim, So-Mang;OH, Jong-Min;Koo, Sang-Mo
    • Journal of IKEEE
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    • v.20 no.2
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    • pp.177-180
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    • 2016
  • The effect of varying thickness of Ag/Ti metal bilayer and annealing time have investigated for controlling self-organized nanoparticles (NPs) on 4H-SiC substrate. In addition, Glass and Si substrate which have different surface energy from SiC were fabricated for analyzing interaction of agglomeration. The results of FE-SEM indicated the different formation behaviors of NPs in various ranges of fabrication condition. The surface energy was measured by using a Contact Angle Analyzer. The formation of network-like NPs was observed on Glass and 4H-SiC, respectively, whereas it was not the case on Si substrates. It has been found that the size of NPs increases with decreasing surface energy, due to particle size-dependent hydrophilic properties of substrates. The different formation behavior was explained by using Young's equation for the contact angles between the metal and different substrates.

Characteristics of Shear Strength for joined SiC-SiC Ceramics (SiC세라믹스 동종재 접합재의 전단강도 특성 평가)

  • Yoon, Han Ki;Jung, Hun Chea;Hinoki, T.;Kohyama, A.
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.5
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    • pp.483-487
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    • 2014
  • In this study, joining methods with SiC powder as the joining adhesives were studied in order to avoid the residual stresses coming from CTE (Coefficient of Thermal Expansion) mismatch between substrate and joining layer. The shear strength and microstructure of joined material between SiC substrates are investigated. The commercial Hexoloy-SA (Saint-Gobain Ceramics, USA) used in this work as substrate material. The fine ${\beta}$-SiC nano-powder which the average particle size is below 30 nm, $Al_2O_3$, $Y_2O_3$, and $SiO_2$ were used as joining adhesives. The specimens were joined with 20MPa and $1400-1900^{\circ}C$ by hot pressing in argon atmosphere. The shear test was performed to investigate the bonding strength. The cross-section of the joint was characterized by using an optical microscope and scanning electron microscopy (SEM).