摘要:

The dependence of grain‐boundary resistivity and resistance per square centimeter of grain‐boundary surface on grain‐boundary density (D) in yttria‐stabilized zirconia was investigated using reported data. The grain‐boundary resistivity increased with increasing D in the high‐D region but was independent of D in the low‐D region. These results were interpreted in terms of intrinsic effects such as lattice irregularity and extrinsic effects such as impurit

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19658.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The pseudobinary system Ga2O3‐Bi2‐x3+Bix5+O3+x2‐was studied in view of its importance for growth of SrGa12O19crystals from a bismuth oxide flux. A subsolidus transition of γ*‐Bi2O3to a β′‐phase and a strictly stoichiometric 1:2 phase with 33.3 mol% bismuth oxide were found. The single‐crystal data for the compound indicated space group P21212, with lattice constants a=0.79180±0.0003 nm, b =0.8288±0.0003 nm, and c =0.5889±0.0003 nm; the measured density was 7.1±0.3 g/cm3and the

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19659.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The surface tension of a 62ZrF4.33BaF2.5LaF3(mol%) glass was measured by a solidified pendant drop technique. The surface tension at 550°C is 0.174 ± 0.005 J/m

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19660.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The effect of residual contact stresses on the dynamic fatigue behavior of indentation flaws was analyzed using an exponential‐law crack velocity function based on stress corrosion theory. Analysis of strength data from Vickers‐indented soda‐lime glass specimens in water showed that the contact residual stress can be properly accounted for and that the exponential‐law fatigue parameters can be straightforwardly o

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19661.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Sols in which the viscosity changes by only 4%/h in the range 1.5 to 150 Pa.s were produced, and fibers with diameters between 20 and 500 pm were hand‐drawn from them. Sols remain fiberizable for<140 h at room temperature. Periodic additions of alcohol increase the time available for fiberizing to ≥ 30

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19662.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The residual driving force of plastic zones associated with indenter flaws was modeled as that of a compressed spring. The limiting case of a zero‐stiffness spring converges to the constant‐force model and predicts maximum stable crack extension before instability and corresponding maximum strength degradation. An infinitely stiff spring, i.e. a rigid wedge, causes no stable crack growth or strength degradation. Comparison with stable‐crack‐growth data suggests that an appropriate‐stiffness spring model gives a better fit than the constant‐

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19663.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

In the normal paradigm of sintering‐densification, grain growth, creep, etc., it is anticipated that, at extremely fine grain size, various phenomena will be exaggerated so as to make direct observation more tractable; this gives impetus to attempts to synthesize such fine‐grained materials. In the present case, 6‐nm monoclinic zirconia was produced by a hydrothermal technique and is showing very interesting grain growth and rearrangement effects in transmission electron micro

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19664.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A loading dilatometer of novel design was used to study the sintering behavior of CdO powder compacts subjected to stresses between 0 and 0.25 MPa at 973 to 1123 K. Densification and creep occur simultaneously. Although both the volumetric densifcation rate and the uniaxial creep rate show an approximately inverse relation with time, the creep rate increases with stress, whereas the densification rate is independent of stress.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19665.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Reaction‐bonded silicon nitride was isostatically hot‐pressed under 138 MPa for 2 h at 1850°, 1950°, or 2050°C. Nearly theoretically dense specimens resulted. The room‐temperature flexural strength more than doubled, but the 1200°C flexural strength increased significantly only after pressing at 2050°C.f. ∼35% improvement). An amorphous phase introduced by hot isostatic pressing accounts in part for t

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19666.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Vitreous silica exhibits a characteristic absorption band at 3.81 μm which was attributed previously to a combination frequency of SiO4fundamentals. Deuterium treatment of water‐containing fused silica also gives rise to an absorption band at 3.81‐μm. An analysis of the previously characterized 3.81‐μm band and its relation to absorption bands in deuterated specimens is p

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19667.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY