The molding properties of cast bodies such as stiffness, crack forming resistance, mold separation ability and workability in finishing operation were discussed. These properties have been expressed by the equations as functions of the fundamental parameters that had previously reported by the present author. The results are summarized as follows:
1) The stiffness may suitably be given by the strength of surface layers of casts (st_Ds) and average strength of casts (st_D), which can be calculated by the equations st_Ds=Bf(1)(AF₃^2/3)Sa, and st_D=st_Ds×f(d_D/ds)/f(1), respectively. The difference between (st_Ds) and (st_D) relate to the moisture distribution in casing layers during casting (F₃⋅Sa⋅ds), the mold separation coefficient (G) and the yield value of slips (θ).
2) Crack forming resistance of casts may properly be given by the crack resistance coefficient (H⁰) and the time for crack formation (t_K), and they can be calculated from the equations; H₀=Jf(st_Ds)/AG, t_K=FcG(H₀/M-1)/ωF_D.
3) For a good mold separation ability, it is required that the cast strength is satisfactorily greater than the strength of cast-mold-interface. As the strength of the interface is closely related to mold-deflocculant reaction and other interface conditions, it is difficult to estimate the mold separation ability from the fundamental parameters and the coefficient that have been introduced by the author.
4) Workability in finishing operation can suitably be expressed by the maximum deformation of surface layers of casts (D_Ds), which can be given by the equation, D_Ds=Jf(st_Ds).

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Di-strontium boro-aluminate, 2SrO⋅Al₂O₃⋅B₂O₃, has the space group D_2h¹⁰-P_ccn with the following cell constants: a=15.17±0.04Å, b=8.86±0.03Å, c=5.48±0.02Å and Z=4.
Three dimensional Patterson and electron density syntheses were carried out, based on 119 visually estimated structure factors. The structure obtained was refined by the method of least squares, which led to a reliability index of R=16.3%.
The structure consists of chains run parallel to the c-axis and are built up of AlO₄-tetrahedra and BO₃-triangles. The basic unit of these chains is a six-membered ring which consists of two AlO₄-tetrahedrons and one BO₃-triangle. The six-membered ring is a new kind of complex polyanions. Sr atom is co-ordinated by 8 oxygen atoms. The strontium atoms serve to hold the chains together through co-ordination with oxygen atoms.

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A method has been developed for the determination of sodium content of ceramics using a sodium-ion responsive glass electrode.
Procedure: Transfer about 0.05-0.5g ground samples into a platinum dish. Add 0.5ml water as a wetting agent. Then add 2ml HClO₄ and 10ml hydrofluoric acid, and heat the dish on a sand bath. Cool the dish add 5ml HCl and water, and warm it on a steam bath to dissolve salts. Transfer to a 100ml volumetric flask and made it up to 100ml with water.
To ensure that the ionic strength and pH of the solution remained constant, 20ml of sample solution were mixed with 20ml of the buffer solution. The electrodes were placed into the solution and the sodium ion activity was measured.
The concentration of sodium ion was determined from the calibration curve obtained previously and the percentage of sodium oxide in ceramics was calculated.
The results of the developed method for various ceramics were compared with the results of flame-photometric method and these two results were in good agreement.
The standard deviation of determination was 0.04% for the content of Na₂O 13.7%.

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Dissolving equation of alkali from glasses in silica-soda system was studied in this paper.
Many kinds of glasses in system of (1) SiO₂-Na₂O-RO, (2) SiO₂-Na₂O-CaO, and SiO₂-Na₂O-ZnO, (3) SiO₂-Na₂O-(xRO+yR′O), (4) SiO₂-Na₂O-TiO₂, and SiO₂-Na₂O-V₂O₅ were melted in electric furnace.
The melted glasses were powdered into particles of 35-60 meshes and 2g of them were immersed in 50ml water of 30°, 40°, 50°, 60° and 70°C, while being stirred during 10, 20, 40, 80 and 160 minutes respectively.
The results were as follows;
1) The experimental data were tested by analysis of variance and it was found that log of dissolved amounts was linear function of log of dissolving time at constant dissolving temperature and the slopes of their linear equations were about 0.5.
2) It was found that log of dissolved amounts was linear function of reciprocal of dissolving temperature at constant dissolving time and the slopes of their equations, that is, the apparent dissolution energy was approximately constant in all glasses.

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Crystallization process and some properties of the calcium magnesium silico-phosphate glass containing small amount of fluorine have been studied. Calcium fluoride was added to a base glass with the molar composition of 3.5CaO-3.5MgO-P₂O₅-3.5SiO₂, which belongs to the high oxygen type silico-phosphate glass (cf. T. Kanazawa, Yogyo-Kyokai-Shi 72, 27 (1964); T. Kanazawa, A. Nakai, H. Kawazoe, Kogyo Kagaku Zasshi 72, 2211 (1969)), in expectation of preparing glasses containing 0.1, 0.5, 1.0 and 1.5wt% of fluorine. On these four glass samples heat-treated and untreated, DTA, electron microscopic observation, EPMA and measurements of thermal expansion, viscosity, acid solubility and others were carried out.
In the DTA profile, the temperature (T_p) of the firstly exothermic peak, which appearance is due to the formation of fluorapatite (FAp) crystals, was reduced with increasing the fluorine content in the glass. It was seen that the introduction of fluorine resulted in a decrease of the viscosity of every glass specimen in its transformation range. These facts show that the change of T_p is considered to be related mainly to the viscosity change by varying the fluorine content.
In the glasses containing fluorine above 0.4wt%, the crystallization of FAp was observed to begin at both the surface and the inside of the test piece simultaneously. The electron micrographs by the transmission method proved the formation of droplets with 200-400 Å in size. These droplets were recognized in the untreated glass similar to the heat-treated. The fine crystals of FAp seemed to form at the interfaces between the droplets and the surrounding matrix region. The composition of these droplets is considered to be rich in magnesium. In comparison of the above-stated results with those of the glass samples containing fluorine below 0.1wt%, it was suggested that the homogeneity of the crystallization of FAp was attributed to the homogeneous dispersion of these droplets in the glass specimen.
During the growth of FAp crystals, the glass specimen with fluorine content of above 0.4wt% was found to have a two-phase structure with Ca-rich and Mg-rich phases. As the Ca-rich phase contained numerous FAp crystals, which solubility to the acid solvent was considerably lower than that of the starting glass, the dissolving process of the fluorine containing test piece to N/2 hydrochloric acid was considered to be different in appearance from that of the glasses with fluorine content of below 0.1wt%.

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First, sintered ceramics of BaTiO₃, CaTiO₃, Pb(Ti, Zr)O₃, and TiO₂ were prepared by the conventional method. Then, the disks were coated with powders of metal oxide or carbonate such as CuO, Bi₂O₃, La₂O₃, PbO, Co₂O₃, Cr₂O₃, Fe₂O₃, MnCO₃ and SrCO₃. The injection of various impurities by thermal diffusion were made by heating the ceramice at 1100°-1450°C for 0.5-4h. For these specimens, diffusion depth of the injected impurities into the base ceramics, distribution patterns of the impurities in the ceramics, and effects of the impurities on the electrical properties of the ceramic dielectrics were examined systematically. Main results obtained are summarized as follows.
1) Ceramic dielectrics with injected impurities by means of thermal diffusion show properties differing from those with impurities added during the powder stage of the conventional ceramic technique.
2) The distribution patterns of the injected impurities were examined by X-ray microanalyzer for CaTiO₃ semiconducting ceramic with the injected bismuth oxide, TiO₂, ceramic with the injected copper oxide, and BaTiO₃ ceramic with the injected manganese oxide. As a result, it was ascertained that the injected impurities were located at the grain boundaries.
3) By modifying the characteristics of the grain boundaries by means of thermal diffusion of the injected impurities, we can control the electrical and piezoelectric properties of ceramic dielectrics such as the electromechanical coupling coefficient of BaTiO₃ ceramic or the propagation characteristics of surface wave on the PZT ceramic.

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