摘要:

The kinetics of copper‐potassium ion exchange of potassium aluminosilicate glass have been investigated in molten CuCl at 550°C in air and nitrogen. The presence of oxygen dissolved in molten CuCl has a great effect on the Cu‐K ion‐exchange kinetics, i.e. ion exchange in nitrogen is controlled by the interdiffusion process of Cu+and K+in the glass, whereas ion exchange in air seems to be controlled by the Cu+→Cu2+oxidation

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19177.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A method for measuring the solubility limit of refractory oxides in glass is presented, and the solubilities of Al2O3, ZrO2, SnO2, and Cr2O3in soda‐lime glass are given as a function of temperature. The order of solubility in soda‐lime glass is Al2O3ZrO2SnO2Cr2O3at 1300° to 16Q0°C. The solubility of ZrO2in Al2O3‐saturated soda‐lime glass is much lower than that in pure soda

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19178.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Studies of fracture strength of abraded and as‐received glass tubes as a function of etching depth showed that at depths less than the calculated initial flaw depth (∼50 μm) the strength increase was almost entirely due to reduction inflow depth from etching. This result is consistent with model 1 proposed by Proctor; it disagrees with his interpretation of his own results, no doubt because his study focused on etching depths of ≥

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19179.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The fracture strength of HF‐etched samples was measured as a function of field‐assisted K‐Na ion exchange depth, as well as the severity of abrasion. As expected, the more severe the abrasion, the greater the depth required to make the strength insensitive to abrasion. An abrasion‐independent weakening mechanism that increased with exchange depth was also found to be op

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19180.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The rates of escape of short‐lived isotopes of xenon and krypton to the coolant from a deliberately defected UO2fuel element are at least 100 times greater than the release rates for identical species within an intact element. The enhanced escape is consistent with accelerated transport mechanisms under defect conditions. The rate of escape to the coolant of radioiodines is less than that for the short‐lived gases, reflecting strong bonding between the iodine species and internal UO2and zirconium alloy surfa

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19181.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A complete solid solution series exists between Mg2Al4Si5O18and Co2Al4Si5O18at temperatures below 1160°C. Above 1160°, Co cordierite breaks down into CoAl2O4spinel and cristobalite. The thermal stability of the cordierite solid solution decreases with decreasing Mg content; at the Co/(Co+Mg)=0.3 composition incongruent melting of the cordierites is changed to a subsolidus breakdow

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19182.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Transformation range viscosity was measured for multicomponent fluorozirconate glasses in the system 0.56ZrF4·(0.34‐x)BaF2·0.06LaF3·0.04AlF3·xRF, whereR =Li, Na, K, or Cs. The results indicate that the viscosity of these glasses can be described by an Arrhenius equation over the viscosity range from 107to 1012Pa·s with an activation energy of the order of 650 to 850 kJ. In general, the effects of alkali fluoride additions on the viscosity of fluorozirconate glasses are comparable to those in silicate s

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19183.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Calculations of fracture toughness (KIC) from the applied‐moment double‐cantilever‐beam test have assumed negligible groove effects and crack propagation along the center of the specimen. A rigorous analysis is presented, and procedures for routine measurements are suggested to correct for both the presence of the groove and off‐center cracking. For a typical specimen, neglect of these factors results in ≥10% error. The corrections introduced allow results to be obtained from miniaturized

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19184.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

The pH of the solution from which the gel is precipitated determines the calcined zirconia crystal phase. Monoclinic zirconia is produced from materials precipitated in the 6.5 to 10.4 pH range; the tetragonal precursor is obtained for the 3 to 4 or 13 to 14 pH range. The calcination atmosphere, temperature history during calcination, and the presence of alkali do not appear to play a dominant role in determining the zirconia phase composition.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19185.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Many ceramics are polyphase, requiring the mixing of two or more powders. Recent work suggests that colloidal processing methods are desirable, i.e. the handling of powders, in either dispersed or flocced states. We have demonstrated that a high‐shear‐rate mixer can be used to produce a homogeneous mixture of two flocced suspensi

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1984.tb19186.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY