• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1078-1079
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• 2006

The paper presents the possibilities of obtaining new composite materials based on sintered porous ceramics with particles and fibre of $Al_2O_3$ infiltrated by aluminum alloy. The EN AC - AlSi12 alloy features the matrix material, whereas the RF50AX-301 preform, of Saffil Automotive, was used as the reinforcement. Examinations of ceramics preforms permeability were made. Metallographic examination of composite materials made on light microscope and in scanning electron microscope show that aluminum alloys fill micropores in the matrix. New composite materials show twice higher value of hardness in comparison with matrix. Results indicate that it is possible to infiltrate porous ceramic with liquid aluminum alloy to obtain new composite materials were advantageous properties of each component are connected.

• Composites Research
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• 제36권2호
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• pp.101-107
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• 2023

본 연구에서는 질화알루미늄을 강화재로 갖는 알루미늄기지 복합재료를 질소 분위기에서의 아크용해 공정을 통해 제조하였다. 알루미늄과 질소 원자의 화학반응을 1분간 유지시켰을 때, 중간층과 라멜라층으로 구분되는 질화알루미늄 강화상이 자발적으로 알루미늄 용탕 내부에 형성되어 기지 전반에 분포되었다. 복합재료는 약 10 vol.%의 AlN을 가지며, 이 강화재는 계면에서 낮은 열저항과 강한 결합을 보였다. 제조된 복합재료는 열전도도가 높고 열팽창계수는 낮은 열적 특성 조합을 보였다. 또한, 본 연구의 복합재료는 이종원소인 실리콘을 기지에 첨가함으로써 열팽창계수를 추가적으로 감소시키는 것이 가능했다. 이는 아크 용해법으로 제조된 알루미늄기지 복합재료가 낮은 열팽창계수를 요구하는 방열소재로 적용될 수 있는 가능성을 시사한다.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.188-194
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• 2001

Metal matrix composites with whisker reinforcements have significant potential for demanding mechanical applications including defense, aerospace, and automotive industries. Especially, metal matrix composites, which are reinforced with aluminum borate whisker, have been used for the part of piston head in automobile because of good specific strength and wear resistance. Aluminum alloy-based metal matrix composites with whisker reinforcements have been produced using squeeze casting method, which is kind of an infiltration method. In this study, AC4CH-based metal matrix composites with $Al_{18}B$_4$O_{33}$ reinforcement have been produced using squeeze casting method, after T6 heat treatment, we evaluated mechanical properties of matrix and MMC composite were evaluated.

• Tribology and Lubricants
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• 제19권5호
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• pp.274-279
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• 2003

$Al-SiC_{p}$ composite layer was prepared by plasma thermal spray on aluminum substrate. The homogeneously dispersed composite powder for thermal spray was fabricated by mechanical alloying with ball mill. The friction tests of the composite layers and commercial aluminum alloys for comparison were performed in the temperature range of 20∼$260^{\circ}C$ with the interval of $40^{\circ}C$ with steel counter-face. Friction coefficient was recorded during test sequence, and the microstructure of surface and debris was investigated by optical and scanning electron microscope. Friction coefficients of composite and aluminum alloys at room temperature were similar except pure aluminum. As the temperature increase, friction coefficient was increased rapidly in AC4C, AC2A. But friction coefficient of $Al-SiC_{p}$ composite was not increased so much up to $220^{\circ}C$. Consequently, the reinforcement of $SiC_{p}$ into aluminum matrix increased the stability of friction coefficient as well as wear resistance.

• Journal of Welding and Joining
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• 제22권5호
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• pp.46-52
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• 2004

AlSi-Al$_2$O$_3$ composite layer was prepared by plasma spray on steel substrate. The composite powder for plasma spray was prepared by simple mechanical blending. The wear resistance of the composite layers and matrix aluminum alloy were performed in terms of size distribution of ceramic particles. Friction coefficients of AlSi were decreased with incorporation of $Al_2$O$_3$. The tribological properties of coated layers were affected by the size of incorporated $Al_2$O$_3$ particle. The reinforcement of $Al_2$O$_3$ particle into aluminum alloy matrix decreased the friction coefficient as well as wear loss.

• Restorative Dentistry and Endodontics
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• 제19권2호
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• pp.513-533
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• 1994

The smooth surface after polishing of composite resin contributes to the patient's comfort, and appearance and longevity of the restoration. This study was performed for the quantitative analysis of the effects of the various finishing and polishing instruments on the surface roughness and reflectivity of the microfill, and hybrid composite resins. Cylindrical specimens 2mm thick and 10mm in diameter of Silux Plus, Durafill VS ; Z100, Prisma TPH, Brilliant, and Herculite XR composite resin were polymerized under the matrix strip. 18 specimens for each composite resin materials were divided into 6 groups ; 5 experimental groups were abraded with # 600 sand paper to remove resin-rich layer, except control. Thereafter, using diamond bur(Mani Dia-Burs), carbide bur(E. T. carbide set 4159), rubber point(Composite polishing kit), aluminum-oxide disk(Sof-Lex disk), polishing paste(Enhance system) ; each specimen was polished to its best achievable surface according to manufacturer's directions. Final polished surfaces were evaluated for the surface roughness with profilometer(${\alpha}$-step 200, Tencor instruments, USA) and for the reflectivity with image analyser(Omniment Image Analyser, Buehler, USA). The results were as follows. 1. Polishing paste or aluminum-oxide disk finish in the microfill, and hybrid composite resins was as smooth as matrix strip finish on the surface roughness test. 2. Polishing paste or aluminum-oxide disk finish in the microfill ; polishing paste finish in the hybrid composite resins was as reflective as matrix strip finish on the refectivity test. 3. For the polishing paste, there were no significant differences between the composite resin materials on the surface roughness and refectivity tests. 4. For the aluminum-oxide disk, the best result was obtained with the microfill composite resin on the surface roughness and reflectivity test. 5. Diamond bur, carbide bur, and rubber point were inappropriate for the final polishing instruments.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.38-41
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• 2001

A new 2-D braided textile metal matrix composite was developed and characterized. The constituent materials consist of PAN type carbon fiber as reinforcements and pure aluminum as matrices. The braided preforms of different braider yarn angles were fabricated. For a fixed bundle size of 12K, three braider yarn angles was selected: $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$. The braided preforms were infiltrated with pure Al by vacuum assisted squeeze casting. Through the investigation of melt pressing methods and the effects of process parameters such as applied pressure, and pouring temperature, the optimal process conditions were identified as follows: applied pressure of 60MPa, pouring temperature of $800^{\circ}C$. Using the measured geometric parameters, 3-D engineering constants of metal matrix composites have been determined from the elastic model, which utilizes the coordinate transformation and the averaging of stiffened and compliance constants based upon the volume of each reinforcement and matrix material.

• 대한기계학회논문집A
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• 제27권7호
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• pp.1051-1057
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• 2003

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2％ Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as SiO$_2$, Al$_2$O$_3$, and TiO$_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated TiO$_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.198-203
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• 2001

This study is about controlled impurities, which make metal alloys, especially AC4CH alloy that is made by restraining 0.2% Fe and Aluminum to make a matrix material. A metal matrix composite is produced using the squeeze casting method. The first step in the squeeze casting method is to add some organic binder including aluminum borate whisker into the matrix. After the fabrication of a metal matrix composite, each is individually appended to an inanimate binder such as $SiO_2,\;Al_2O_3$, and $TiO_2$. Through experiments the mechanical property changes were investigated between the metal matrix composite and AC4CH alloy. This study proves the superiority of the mechanical property of a metal matrix composites over AC4CH according to the previous tests and results that were mentioned above. One excellent property of matrix material composites is the infiltrated $TiO_2$ reinforcement. This material is a good substitute for the existing materials that are used in the development of industries today.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.35-38
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• 2004

Graphite nanofiber (GNF) and carbon nanotube (CNT) are novel fiber reinforcing materials which have outstanding physical and mechanical properties. Aluminum matrix composites reinforced graphite nanofiber were fabricated by conventional powder metallurgy (PM) method. The composites were prepared through ultrasonication, ball milling, and hot isostatic pressing. A uniform distribution of GNF in aluminum matrix could be obtained. To measure the mechanical properties of GNF-Al composites testings were done in indentation and compression. The compressive strength was enhanced according to reinforcing graphite nanofiber while the hardness was decreased. This study makes the high performance composites for future applications.