ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12990.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Equations developed from simplifying assumptions related the flow rate of water into kaolinite plugs to the clay‐water contact angle, and showed that the wettabilities were reduced by ammonium, methylammonium, or ethylammonium as exchangeable cations, or by ammonia, methyl‐amine, or ethylamine as physically held adsorbates. Poorly crystalline kaolinites were especially affected by these cations. Both the exchangeable cations and the crystal surfaces between the exchange sites influenced wettability. These surfaces, unless partly or completely covered by ammonia or amines, enhanced wettability when crystallinity was poor. Ethylamine markedly decreased the wettability of kaolinite with good crystallinity, probably because it was difficult to displace from cavities in the stacklike crystals. Kaolinite with montmorillonite behaved anomalou

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12991.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Polymorphic transitions in CasSiO6have been investigated by precise high‐temperature X‐ray diffractometer measurements and by differential thermal analyses. In addition to change caused by normal thermal expansion, three principal crystallographic transformations take place: α‐triclinic–β–triclinic (sluggish) in the range 550° to 700°C; 8‐triclinic‐monoclinic at 910°± 10°C; and monoclinic‐trigonal at 970°± 10°C. The sluggish 550° to 700° C reaction alternatively may be interpreted as two separate triclinic‐triclinic transitions, accompanied by broad endothermic h

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12992.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

A number of empirical and semiempirical expressions which relate the strength of brittle polycrystalline materials to the total porosity have been proposed by various investigators. The present study demonstrates from a purely theoretical point of view that not only the total porosity but the pore shape and orientation are important factors affecting the strength. A strength‐porosity relation is derived that takes pore shape and orientation into account. Examples of how various types of pores should affect the strength are presente

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12993.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The elastic modulus and transverse bend strength of pure, dense alumina specimens were determined as a function of grain size (1 to 250μ) and temperature (30° to 1500°C). The elastic modulus was essentially independent of grain size over the temperature range covered. The transverse bend strength for fine–grain–sized alumina was substantially greater than that for larger–grain–sized alumina over the entire temperature range, although, at the highest temperatures, the rate of decrease of strength with temperature was greatest for the he–grained material. Fine–grained alumina (1 to 2P) exhibited considerable yielding and nonlinear load–deflection behavior at 1000°C and above. At 150O°C, the 1‐ to 2‐μ specimens bent to the limit of the apparatus without fracturing (approximately

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12994.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Phase equilibrium relations in the system Li2O‐GeO2were determined using standard quenching techniques. In contrast to published literature five congruently melting compounds were found to exist. They are Li2O·7GeO2, 3Li2O O·8GeO2, Li2O O·GeO2, 3Li2O O·2GeO2, and 2Li2O.‐GeO2. The melting points, respectively, are 1033°± 5°C, 953°± 5°C, 1245°± 15°C, 1125°± 15°C, and 1280°± 15°C. Simple binary eutectic relations exist among the compounds. The eutectic temperature between 1:7 and GeO2is 1025°± 1h0°C at about 96.8 wt% GeO2; the eutectic temperature between the 1:7 and 3:8 compounds is 935°± 10°C at about 90.9 wt% GeO2; the eutectic temperature between the 3:8 and 1:1 compounds is 930°± 10 °C at about 89.8 wt% GeO2. Liquidus data for compositions richer in lithia than the 1:1 compound are only approximate because of the difficulty of quenching them; the phase relations between the 1:1 and 3:2 and between the 3:2 and 2:l compounds, however, are found to be of the simple binary eutectic type. The glass–forming region was also determined. Melts allowed to cool in air crystallized. When, however, the melts were quenched, glasses containing as much as 8 wt% GeO2could be prepared in 5–g quantities. Both the refractive index–composition and density–composition curves for the glasses sh

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12995.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The addition of minor amounts of MgO or NiO to Al2O3inhibits grain growth during sintering and allows the sintering process to proceed to theoretical density by maintaining a high diffusion flux of vacancies from the pores to the grain boundaries. The inhibition of grain growth is accomplished by the segregation of solute at the grain boundaries, causing a decrease in the grain–boundary mobility. The segregation of MgO or NiO at the grain boundaries can be inferred from the results of the microhardness studies presented and is substantiated by autoradiographic experiments and also by lattice parameter determinations as a function of grain siz

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12996.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The addition of silicic acid to fibrillar colloidal boehmite retarded the conversion at high temperature of gamma alumina to theta and alpha and permitted the formation of an intermediate kappa. Unusually sharp X–ray diffraction patterns for gamma, theta, and kappa transition aluminas are presente

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12997.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

The solubility of carbon dioxide in 25, 35, 43, and 56 wt% soda‐silica melts was investigated. Anomalous results obtained by other workers are explained on the basis of the large viscosity and viscosity‐temperature relationships which prevail for high‐silica melts. The results are related to the variation of oxygen ion activity with composition and are examined in the light of the data of other workers and current theories of the structure of molten sili

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12998.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

Molten oxides have been of potential interest as fuels for nuclear reactors. To obtain additional information about the constitution of these systems, the molar volume and surface tension of the NaPO4–Li2SO4, NaPO4–Na2SO4, NaPO4–Rb2SO4, and NaPO3–UO2SO4solutions were determined for the NaPO2–rich region. The observed properties were found to vary linearly with temperature in all cases. Although the results of other types of investigations were found to be nonideal, the volume behavior of all the mixtures was

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1964.tb12999.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY