Xonotlite grains having spherical shape of 10-100μm diameter and twisted texture of needle like crystals were fired and inverted to wollastonite grains having the same shape and texture. When the firing temperature was below 1100°C, β-wollastonite was formed throughly reserving the original shape and texture of xontlite grains, while at 1150°C the shape and texture were slightly distorted and at 1200°C α-wollastonite was formed accompanying the sintering and distortion of needle like crystals and grains.
An aqueous slurry of β-wollastonite powder was molded, pressed and dried. Thus prepared molded materials have bulk density of 0.2-0.3g/cm³, bending strength of 4-5kg/cm², heat shrinkage of 0.1% at 1000°C and excellent quality for high temperature heat insulator.

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Test specimens were prepared from an artificially graded quartz sand and a commercial hydrated lime and autoclaved for different curing times from 24 to 96 hours at steam pressure of 10kg/cm². Changes of bending and compressive strength by the curing time and by the heating temperature of specimens up to about 800°C were tested. The phase changes under these tests have been studied by X-ray, differential thermal, chemical, electron microscope methods and the pore distributions were determined by nitrogen absorption method.
The bending strength rised to a maximum at the autoclaving time of 24 hours but the compressive strength rised progressively up to 48 hours. The phases in the specimens cured from 12 to 24 hours were formed by fibrous or crinkly foiled semi-crystalline tobermorite but the phases cured for about 48 hours were formed by platy crystalline tobermorite. On heating, the specimens with lath like or fibrous phase gave a progressive increase in compressive strength with increase in heating temperature up to 400°C, but those with platy crystalline phase gave the reduction of strength by heating at 300°C because of its inversion. Lath like phase made a net-work structure by heating at 200°C thus they gave a fairly great increase of strength, the other side the fibrous phase was stable and did not show a remarkable phase change up to 800°C. Pore size distributions were determind from nitrogen absorption isotherms using the BET procedure and the changes of phases were investigated in comparison with the electron microscope observation.

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Densities and Knoop hardnesses of As-Se and Cu-As-Se glasses were measured and correlated with the glass structure. On the As-Se binary system, the density and hardness were measured as functions of As content. In these curves, minimum points were found near 55-60 at% As, in addition to a well known maximum at 40 at% As. When Cu was added to the As-Se binary system, the minimum point in the As-rich region shifted toward the As-poor side. The compositions corresponding to the minimum, i.e. (55-60As, 40-45Se), (5Cu, 50As, 45Se) and (10Cu, 45-50As, 40-45Se), could be approximately connected by a line in Cu-As-Se diagram. This line divided the glass formation region of the Cu-As-Se system into two different glass structure regions. When Cu was added to As₂Se₃, both density and hardness increased with increasing Cu content, but the rate of increase changed at 15-20 at% Cu. In the As- and Cu-poor region, it is considered that Cu atoms added to the As-Se binary system fill up vacancies in the As-Se glass structure and increase the density. It is also stated that Cu results in Cu-Se bond, increasing the hardness. In the As- and Cu-rich region, metallic bond such as Cu-Cu is supposed to be formed. The structure having the metallic bond may be correlated to the peculiar phenomena, for instance, voltage controlled switching effect of the glass in this structure region.

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窒化チタン (TiN) の焼結に関する既報の研究例は数少ない. この報告はTiN-CoおよびTiN-WC-Co系合金の焼結に関したものである. すなわち, X線回折, E. P. M. A., I. M. A., 諸焼結特性の測定, および合金の強度測度などによって基本的諸現象に検討を加えた.
おもな実験条件は次の通りである.
1) 合金組成 (重量%),
TiN-20wt% Co, TiN-25wt% Co, TiN-10wt% WC-20wt% Co, TiN-5wt% WC-25wt% Co, TiN-40wt% WC-20wt% Co
2) 焼結条件,
1600℃, 1700℃, 1800℃, 10-240min, Ar気流中
その結果, 次のような知見を得た.
用いた主原料TiNとCoの間には, 相互の溶解現象 (少量と思かれる) が認められた. また, これにWCを加えたTiN-WC-Co 3元系合金では, WCが他の2相に溶解する. おもにW原子がCo相に, C原子がTiN相へ溶解することを推察した. 2および3元系 (40WC添加系を除く) 合金の主構成相は粒子相であるTiN相, およびその結合相のCo相である.
合金組織の検討によれば, 2元系合金では焼結初期から粒子相のスケルトンが形成され, この系におけるTiN粒子のCo相に対する不完全な濡れ性が推察された. しかし, 3元系合金ではこのような現象が認められなかった. これはWC添加により濡れ性がある程度改善されたことによると考えられる.
TiN-10WC-20Co系の液相焼結過程のうち, 予想したsolution-precipitation過程を解析した結果, この過程は固-液界面における反応に律速されることを推察した.
合金の機械強度はTiN-WC-Co 3元系合金の方で一般にTiN-Co 2元系合金に優ったが, これはおもに結合相の差異によるものと思われた.

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The dc and ac conductivities and thermoelectric power were measured for As₂Se₃-based oxychalcogenide glasses in the systems As₂Se₃-As₂O₃, As₂Se₃-SeO₂, As₂Se₃-CuO and As₂Se₃-V₂O₅. These glasses were shown to be inhomogeneous by the electron microscopic observations. The conductivities of As₂Se₃-As₂O₃ and As₂Se₃-SeO₂ glasses show the temperature and frequency dependencies similar to those of the base glass As₂Se₃, and also a slight composition dependence. These results are explained with the following reaction taking place in the melting process of the glasses:
2As₂Se₃+3SeO₂→2As₂O₃+9Se.
The dc conductivity of As₂Se₃-CuO glasses increases monotonically as the content of Cuo increases. This increase in conductivity can be explained in relation to the reaction
5As₂Se₃+6CuO→6CuAsSe+2As₂O₃+9Se,
taking place in the melting process. This reaction implies that copper enters the skeleton to form weaker bonds in the glasses and their band gap becomes smaller. With this change in band gap the conductivity becomes independent of the frequency as high as about 10⁵-10⁷Hz, since the contribution of the band conduction to the total conductivity increases. The dc conductivity of As₂Se₃-V₂O₅ glasses increases abruptly by about six to seven orders of magnitude at the composition of about 5mol% V₂O₅. This phenomenon is attributed to the formation of a dispersed conductive phase including the component resulted from the reduction of V₂O₅ by As₂Se₃, and to the change of the phase to an electrically continuous phase near 5mol% V₂O₅. In the conductive phase the exchange of electrons occurs between V⁴⁺ and V⁵⁺ in V⁴⁺-O-V⁵⁺. This suggestion is supported by the measurement of thermoelectric power: the power varies from positive to negative one with slight temperature dependence, when the content of V₂O₅ exceeds about 5mol%.

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マグネシア単結晶および多孔質焼結体の真空中での自由蒸発に対する気孔率の影響を調べる目的で1400°-1650℃の温度範囲で研究した.
多孔質マグネシアの蒸発速度V(g/cm²・sec)はその見掛け気孔率 (p) の増加とともに増大し, V=V₀・10^pと表記できた. ここで, V₀は単結晶の蒸発速度である. この促進効果は表面のラフネスによる有効表面積の増大と気孔の擬クヌートセン・セルとしての作用により説明された.
種々の気孔率をもつ試料に対する蒸発係数は温度の上昇とともに増し, その融点での外挿値は1となった. それゆえ, マグネシアの蒸発速度における融点での不連続性は存在しないと推定された.

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In order to prepare small spherical alumina particles by means of a plasma flame, a feeder of fluidized bed type was devised, and effects of operating conditions of the plasma on preparation of alumina spheres were investigated. Characters of the alumina spheres obtained were also examined. Results obtained were summarized as follows:
1) The higher was the temperature of plasma flame, the more amounts of spherical particles were prepared. Almost all of particles smaller than 8μ and 80-90% of particles smaller than 15μ became spheres, when the plasma torch was operated with following condition: 2-3g/min of raw alumina powder with 3-5l/min of the amount of gas flow and 400A of arc electric current and 20l/min of the amount of arc gas flow.
2) State of surface and internal texture of the spheres obtained varied with particle size of the samples and with operating conditions of the plasma torch.
3) The small alumina spheres contained appreciable amounts of γ-alumina with α-one. Amounts of the γ-alumina increased with decrease of particle size of the spheres. Lattice constant of the γ-alumina increased with increase of temperature of the plasma flame, but did not change with particle size of the spheres. Inversion of the γ-alumina to α-one began at 950°C and finished nearly completely at 1300°C for 1h except of remaining small amount of θ-alumina.

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空間群と格子定数が与えられているとき, 特定の波長のX線に対し, 必要にして十分な回折をdの大きい順にdのある最小値まで求め, hkl, d, 2θ, 多重度, KSNR (単独ピークか重なったピークかの記号) を列記するプログラムを書いた.

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