摘要:

Exothermic reactions are observed at ∼400°C in alumina powders ball‐milled in isopropanol. These are believed to be due to the oxidation of an Al2O3‐alcohol reaction product formed during m

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10278.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The electrical conductivity of iron‐containing silica glasses was measured from 80 to 350 K. The conductivity data were analyzed based on the hopping conduction theory. The hopping binding energy (Wp) and disorder energy WD) were calculated from the activation energy at high and low temperatures. The disorder energy obtained was much lower than reported for FeO‐P2O5glasses, but similar to that for vandium‐containing gl

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10279.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The phase equilibrium diagram of the system ThO2‐Nb2O was redetermined near the composition Th2Nb2O9. This phase was found to melt incongruenlly at 1362°C, with a eutectic temperature at ∼1350°C. The peritectic and eutectic compositions must occur between 60 and ∼64 mol % ThO2. From single crystal and powder X‐ray diffraction data, Th2Nb2O9was found to have a primitive monoclinic unit cell with a = 6.711(1), b = 25.254(5), c=7.757(1)×10−1nm,

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10280.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Chemical polishing and dislocation etch pit observations have been applied to the study of the depth of penetration of dislocations produced by abrading (100) surfaces of MgO. From the results it has been concluded that such dislocations penetrate from 100 to 700 μm depending on the source of the material. Heating of the abraded samples for short times up to 1300°C has little influence on the depth of penetratio

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10281.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Cr2O3and ZrO2were mixed in various ratios and pressed to form compacts, which were then sintered in carbon powder. Compacts with>30 wt% Cr2O3were sintered to densities>98% of true density at 1500°C. This method of sintering in carbon powder can be used to prepare very dense Cr2O3‐ZrO2ceramics at a relatively low temperature, (∼1500°C) without addi

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10282.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Grain‐oriented ceramics of ferroelectric lead metaniobate have been prepared by molten salt synthesis of anisotropic crystallites followed by doctor blade casting. The sintered ceramics have an orthorhombic texture with elongated c axis grains parallel to the casting direction. This allows efficient poling in directions perpendicular to the tap

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10283.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

An attempt to apply three‐dimensional flaw models to characterize fracture origins in sintered alpha silicon carbide is made. Some general improvements in the intrinsic flaw fractography results are obtained by using three‐dimensional void models instead of two‐dimensional crack m

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10284.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

An X‐ray method to determine the transformation zone size in ceramics containing tetragonal ZrO2is described. Results obtained on plane fracture surfaces of various composites were correlated to mechanical property data and TEM observations and were found to be in good agreement. This indicates that the method presented is a useful tool for estimating stress‐induced transformation zone sizes and for checking the effectiveness of tetragonal particles introduced in a ceramic mat

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10285.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Exposed to Pt‐saturated air, the surface of MgO crystals becomes spotted with metallic Pt crystals. The Pt is found concentrated along the interfaces between MgO crystal

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10286.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

A new technique of coating ceramic ware using two‐step drain casting is described in which small alumina crucibles are drain cast followed by drain casting a magnesia coat in the same mold. Cosintering at 1500°C resulted in ware defects unless heating schedules embodying arrests at lower temperatures were us

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1981.tb10287.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY