摘要:

A sintered apatite with enhanced strength was achieved by incorporating CaO‐P2O5/metal oxide frit. When BaO or Al203were partially substituted for CaO in the frit composition, the sintered product was stronger because grain growth was retarded. The average bending strength of the strongest sintered apatite was205.8 M

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19487.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The high‐pressure self‐combustion sintering process can be used to synthesize and simultaneously sinter ceramics in a very short time by taking advantage of exothermic reactions under high pressure. A dense TiB2compact was fabricated in a few seconds by electric ignition on one end of a powdered mixture of Ti and B under 3

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19488.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A three‐component glass system (Mg–Al–Si) was nitrided by adding amorphous and crystalline Si3N4. Glasses with varying amounts of nitrogen were melted, and their mechanical properties were measured. Density, hardness, Young's elastic modulus, and fracture toughness increased with increasing nitrogen co

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19489.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Published results for window glass panel failures were analyzed by using finite‐difference methods to determine the stress states at the fracture origins. Although the state of stress was often complex, it was found that the maximum principal tensile stress at the fracture origin correlated with the fracture mirror. size. Fracture mirror constants were calculated and found to agree closely with published value

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19490.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Boehmite sol‐gels were seeded by adding<2.0 wt%α‐alumina powder to a 20% boehmite hydrosol at pH =3. The seeded gel sintered to 98% of theoretical density after 100 min at 1200°C, whereas the unseeded gel had to be sintered at 1600°C to reach 94% of theoretical density. This difference results primarily from nucleation by the α‐alumina seeds and enhanced transformation of the boehmite to α‐alumina, such that a uniform, well‐ordered, fine‐grained α‐alumina micro‐structure forms p

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19491.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Carbon dioxide from carbonate batch materials oxidizes Si3N4, causing N2loss from oxynitride glass melts. Lithia is the only alkali which is compatible with oxynitride melts; all other alkalis are reduced and volatilized during melting. A high partial pressure of oxygen (P02over oxynitride melts oxidizes Si3N4, leading to N2loss, whereas a low Po2, results in vaporization of SiO.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19492.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Glasses in the metallic alloy system Pd10‐7,Ni10‐70P14‐26were prepared by a melt‐spinning technique. Glasses could also be obtained by substituting Pt for Pd, Mn, Fe, or Co for Ni, and B for P. Densities, molar volumes, melting temperatures, glass transition temperatures, and reduced temperatures were determined. The results are discussed from a structural point

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19493.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Thermal shock behavior was compared for a cordierite glass and glass‐ceramics subjected to a water quench. Crystallization significantly increases the critical quenching temperature difference (ΔTc); this effect was attributed to enhanced strength and thermal conductivity offset by a corresponding increase in Young's modulus. The strength retained following thermal shock also increased significantly on crystallization for ΔT>ΔTC, probably as the result of stepwise increases in fracture toughness with increasing crack size of the glass‐c

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19494.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The chemical durability of four fiuorozirconate glasses was tested in distilled water at 20° and 80°C. Overall dissolution of the glasses, obtained from weight losses, followed a nearly perfect t1/2dependence, and evidence for an F‐/OH‐ion exchange between glass and solution was found. These observations, however, do not necessarily imply a simple diffusion‐controlled process. All surfaces were cracked and showed crystalline deposits of differing composition. A protective layer did not form on the

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19495.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The pseudoternary system ZrO2‐YO1.5CrO1.5was studied between 1300° and 1600C in air by °a quenching method. No ordered phase of the type ZrY6O11was detected, but an ordered Zr3Y4O12phase at 1300°C and YCrO3were observed as intermediate compounds. Solid solutions ofZrO2and YO1.5coexisting with CrO1.5and/or YCrO3formed; the apex occurred between 26.5 and 27.5 wt% YO1.5for the cubic ZrO2+CrO1.5+YCrO3, three‐phase region; CrO1.5is slightly soluble in Zr

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19496.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY