ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18916.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

AbstractSamples of shale from the Sew York State Clay and Shale Survey were selected for the study of efflorescence. Some of the shales had no tendency to effloresce after firing whereas others produced slight to heavy efflorescence. A satisfactory means of qualitative and quantitative measurement of soluble salt content was applied to the raw and fired shale specimens. These analyses provided an indication of the liability to effloresce. The causes of the development of soluble salts in these materials were traced. It was found that soluble salts were formed in the ceramic body during firing by reaction with SO2gas and by solid‐state reactions involving SO4ions. The presence of insoluble mineral sulfides and sulfur‐bearing organic compounds in the raw materials were important causes of sulfate formation. The mechanism of sulfate formation was studied. Procedures for the prevention of efflorescence are discus

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18917.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

AbstractThe rate of penetration of air, water, and acetone through porous Vycor‐brand glass is used to calculate the specific surface area, the average pore diameter, and the pore‐population density of this material. The results are in approximate agreement with those obtained using the Brunauer‐Emmett‐Teller adsorption te

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18918.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

AbstractFused alumina, after being subjected to ball milling and acid treatment, may be suspended in water to form a slip. Deflocculation is obtained by the addition of the proper amount and type of either an acid or a base. Both drain and solid castings can be produced successfully from acidic or basic slips. The casting behavior of the slips and the properties of the cast pieces are summarized for variations in pH and specific gravity, the range of pH being 3.00 to 12.50 and the range of specific gravity, 2.60 to 3.00. Although no extensive investigation of the firing behavior was made, sufficient firing was done to indicate that no special techniques are required.

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18919.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

AbstractIn connection with some workonthe color of minerals it was found that the presence of Ti3+in rutile can originate from two basically different causes.The bluish color of certain rutile preparations due to the presence of the Ti3+ion of Ti2O3is the result of (a) reducing conditions causing an oxygen deficiency in the rutile lattice or (b) the presence of cations having a valency higher than four. Replacing a tetravalent titanium ion by a pentavalent ion, for example, Sb5+, forces another titanium ion into the trivalent state in order to maintain the electroneutrality of the lattice The presence of ZrO2in TiO2makes the rutile more susceptible to certain impurities in its lattice, thus enhancing discoloration. The value of these crystal‐chemical considerations for the opacification of enamels and the dielectric properties of ceramic bodies containing rutile or rutile‐zirconia mixed crystals is pointed

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18920.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY

摘要:

AbstractSeveral lead borosilicate glazes with high to low thermal expansion were applied to a bisque whiteware body having porosities ranging from 20 to 30%, and the thermal properties were studied. Test pieces were subjected to an autoclave test at 50, 150, and 300 lb. per sq. in. and to a thermal‐shock test by quenching from 400° to 600°F. into cold water. The thermal‐expansion curves for the various glazes and for the body at each porosity were determined on the interferometer. The glaze‐fit ring test was used to determine the degree of tensile and compressive stress, and these stresses were plotted graphically with the body porosity. The resistance to crazing was increased in both the autoclave and thermal‐shock tests as the thermal expansion of the glazes, as measured on the interferometer, decreased. The 10% porosity body gave the best results in the thermal‐shock test. A close correlation was found between the thermal‐expansion curves for the glazes and bodies of varying porosity and the stress characteristics shown by the glaze

ISSN:0002-7820    

DOI:10.1111/j.1151-2916.1949.tb18921.x

出版商:Blackwell Publishing Ltd    

年代:1949

数据来源: WILEY