| Thermal Diffusivity/Conductivity in SiAlON Ceramics. |
1995 |
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| Authors:
Dean-Mo Liu; Cheng-Jen Chen; Ray R. R. Lee; INDUSTRIAL TECHNOLOGY RESEARCH INST HSINCHU (TAIWAN) MATERIALS RESEARCH LABS
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 | Thermal diffusivity and conductivity of ceramic materials in a system of Si3N4-SiO2-Al2O3-AlN composed of alpha and beta SiAlON (which is well known as duophase SiAlON ceramics) are investigated. Single-phase beta-SiAlON ceramic has a thermal conductivity of 12.44 W/mK. The thermal conductivities of SiAlON ceramics decrease linearly with increasing content of alpha phase and can be best described by the following equation: K=12.46-0.043 f, where f is the weight percentage of ... |
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| THERMAL CONDUCTION IN CR(3)C(2)/SIC COMPOSITE |
1995 |
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| Authors:
Dean-Mo Liu; Bor-Wen Lin
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| Thermal conduction behavior of Cr(3)C(2)/SiC composite is investigated in terms of temperature and SiC content. Experimental results showed that thermal diffusivity of the composite increases with SiC content up to 20 vol% corresponding to a conductivity maximum, then decreases with further increase of SiC. The reduction in diffusivity and conductivity at higher SiC content may due to formation of small amounts of solid solution at the interface and/or of interfacial ... |
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| HEAT CONDUCTION OF COMPOSITES AND ITS DEPENDENCE ON THE MICROSTRUCTURE OF AL(2)O(3)-CR(3)C(2) COMPOSITE |
1995 |
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| Authors:
Dean-Mo Liu; Chen-Tsu Fu
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| Heat conduction behavior of Al(2)O(3)-Cr(3)C(2) composite with Cr(3)C(2) content varying from 0 to 40% in volume were investigated using a laser-flash method. Thermal diffusivity of the composite decreased sharply as first incorporating 10 vol.% of Cr(3)C(2), then increased with further increase of Cr(3)C(2) content up to 40 vol.%. Similar trends were observed for thermal conductivity behavior. The significantly decreased thermal diffusivity as well as thermal conductivity at lower content of ... |
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| ELECTRODISCHARGE-MACHINING OF AL(2)O(3)/CR(3)C(2) COMPOSITE |
1994 |
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| Authors:
KUEN-MING SHU; Chen-Tsu Fu; Dean-Mo Liu
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| This letter describes a preliminary study of EDM on a new composite material system of Al(2)O(3)/Cr(3)C(2), which has demonstrated superior flexural strength and fracture toughness, good resistance to oxidation, and sufficient electrical conductivity. Fine-grained Al(2)O(3) (0.3-0.5 micrometer, Alcoa, A16-SG) powder was mixed with Cr(3)C(2) powder (1-2 micrometer, geade A, Herman C. Stark), 40% in volume, by ball milling for 24 hours with deionized water as the medium. The mixed powder ... |
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| THE EFFECT OF ELECTRODISCHARGE MACHINING ON THE FRACTURE STRENGTH AND SURFACE MICROSTRUCTURE OF AN AL(2)O(3)-CR(3)C(2) COMPOSITE |
1994 |
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| Authors:
Chen-Tsu Fu; JENG-MING WU; Dean-Mo Liu
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| ELECTRODISCHARGE MACHINING (EDM) HAS BEEN PERFORMED ON A CERAMIC COMPOSITE CONTAINING AL(2)O(3) AS THE MATRIX PHASE AND 40 VOL.% CR(3)C(2) AS THE SECONDARY PHASE. THE EXTENT OF SURFACE DAMAGE INDUCED BY EDM WAS EVALUATED IN TERMS OF EDM PULSE CURRENT, FRACTURE STRENGTH AND SURFACE ROUGHNESS OF THE ELECTRODISCHARGE-MACHINED SPECIMENS. SURFACE STRUCTURES INCLUDING FRACTURED AREAS AND RESOLIDIFIED LAYERS WERE EXAMINED USING SCANNING ELECTRON MICROSCOPY, X-RAY ENERGY-DISPERSIVE ANALYSIS AND AUGER ELECTRON SPECTROSCOPY. ... |
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| SINTERING OF (CA(1-X),MG(X))ZR(4)(PO(4))(6) CERAMICS |
1994 |
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| Authors:
Dean-Mo Liu
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| Densification and grain growth of (Ca(1-X), Mg(x)) Zr(4)(PO(4)) (6) (CMZP; where x=0.0, 0.1, and 0.4) ceramics at the intermediate stage of sintering have been investigated. A lattice-diffusion model proposed by Coble with tetrakaidecahedron as a grain shape was employed and appears to be applicable to the sintering of CMZP. The apparent diffusion coefficient of the CMZP ceramics for x=0.0 is lower by approximately three and one orders of magnitude than ... |
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| Improved Mechanical Properties of Cr3C2 Using Particulate SiC Reinforcement. |
1993 |
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| Authors:
Bor-Wen Lin; Dean-Mo Liu; INDUSTRIAL TECHNOLOGY RESEARCH INST HSINCHU (TAIWAN) MATERIALS RESEARCH LABS
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| Silicon carbide particulate reinforced Cr3C2 matrix composites were fabricated using a hot-pressing technique. Effects of SiC content and temperature on the mechanical properties of the composites were investigated systematically. Results showed that an improvement in flexural strength and fracture toughness, i.e., ^700 MPa and 5.7 MPa sq rt m , respectively, can be reached by incorporating 30 vol% of SiC. The flexural strength further increases to 850 MPa at 800 ... |
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| THERMAL EXPANSION OF POROUS (CA(1-X), MG(X))ZR(4)(PO(4))(6) CERAMICS |
1993 |
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| Authors:
Dean-Mo Liu; JESSE J. BROWN JR.
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| The porous (Ca(1-x), Mg(x))Zr(4)(PO(4))(6)-CMZP ceramics, which belong to the ultra-low thermal expansion NZP family, exhibit a near-zero coefficient of thermal expansion. Experimental results showed that the bulk thermal expansion of the polycrystalline CMZP ceramics is unchanged with varying porosity, but changes significantly with the composition and grain size of the ceramics. The coefficient of thermal expansion (CTE) of the porous CMZP ceramics varies from positive to negative with an increase ... |
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