The surface-treatment of the oxide powders, especially, the surface-treatment with the various kinds of alcohol and the surface properties of the surface-treated oxide powders has been reviewed on the following point of view: 1. the procedure of the surface-treatment and their examples, 2. the extent of surface-treatment and its effect, 3. the effect of surface-treatment on the surface properties of the substrate i.e., original silica gel, 4. the thermal properties of the surface groups, 5. the reaction mechanism of alcohol with the surface silanol and 6. possibility of application of the procedure of surface-treatment and of the application of oxide powders treated with alcohol.

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In the mixing process, inhomogeneity in the mixed powder produces the dimensional variation among specimens and bending in a specimen. In this study, the degree of mixing is adopted as the dispersion of the mixing ratio in the mixed powder. The influences of the mixing ratio, the lubricant and the mixing apparatus on the degree of mixing of Cu and Fe powders were studied, and the adhesion of Cu to Fe particles was also studied by using the wet magnetic separation method.
The factors affecting the dimensional variation of sintered machine parts with the mixing process are the mixing ratio, the amount of sample and the state of the surface of particle (shape, etc.). They make the dimensional accuracy worse about 0.47-0.016 percents of size of parts.
The adhesion of Cu to Fe particles is also influenced by the shape of powder, the lubricant and the mixing apparatus. The amount of adhesion becomes larger in the irregular shape of particles and in using the Lodige mixer.

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A study has been made on the transformation features of sintered Cr-Mo steels (Fe-1%Cr-0.2%Mo-0.35%C) made from premixed powders. Metallic Mo powder or Mo carbide powder (Mo₂C) was added to an atomized iron powder together with graphite and Cr carbide powders. The powder mixtures were pressed at 6 t/cm₂, and sintered at 1250°C in vacuum (10_-4 mmHg) for 1 hr. The CCT diagrams and the microstructures of these specimens were compared with those made from prealloyed atomized powder.
The results obtained are as follows;
1) The specimens made from premixed powders formed pores caused by liquid phase formation, and the
pores were surrounded by Mo segregated area.
2) The CCT diagrams of those materials moved to shorter cooling time compared with those made from prealloyed powder.
3) In the specimen which contained Mo carbide powder instead of metallic Mo powder, the critical cooling rate was not improved, but the region of bainite formation was extended to longer cooling time.
Above-mentioned results showed that the Mo carbide was relatively effective for the purpose of homogenization.

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The mechanical properties, tone of color, resistance to corrosion, etc., of TaC-10%Ni(Co) alloys and of TaC-10%Ni alloys with another addition carbides were studied.
It was found that the strength of TaC-Ni alloy was superior, in particular in the alloy with low carbon content, to that of TaC-Co alloy, and moreover it was remarkably improved with increasing amount of addition Mo₂C up to 10 mol% in carbides. It was concluded that the alloys such as low carbon TaC-Mo₂C-Ni, TaC-NbC-Mo₂C-Ni and TaC-NbC-Mo₂C-Ni-Cr alloys (NbC<30 mol% in TaC plus NbC, Cr ?? 1.7 mol%) would be excellent in the above mentioned properties.

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The pyrolysis of the silica gels which are surface-treated with (A)n-butanol, (B) iso-butanol, (C) see-butanol and (D) d-sec butanol was investigated by means of the quadru-pole mass spectra (QPMS) or the gas chromatograph-quadru-pole mass spectra (GC-QPMS). These silica gels were confirmed from their infrared absorption spectra and microanalysis to be sufficiently surface-treated. The pyrolysis has been observed in the following three temperature ranges, i.e., (i) in the vicinity of 150°C, (ii) in the range of 200°-300°C and (iii) 300°-500°C. From the amount of vapors evolved it is shown that this amount was the most appreciable in the range or (iii) and had the maximum at 450°C for (A), at 400°C for (B) and at 375°C for (C) respectively. The behavior of the pyrolysis of (D) was nearly same as the one of (C). The followings were noticed from the analysis of the mass spectra of vapors evolved in these temperature ranges; (1) physisorbed water or unreacted alcohol was released in the temperature range of (i); (2) the water released in the temperature range of (ii) and (iii) was regarded as the one formed by the condensation of unreacted silanols; (3) the principal constituent of the vapors evolved in the temperature range of (ii) was the alcohol used. which was formed by the hydrolysis of the surface groups; (4) the vapors evolved in the temperature range of (iii) still include the respective alcohol, but its amount is small and decrease appreciably with increasing temperature. The principal constituent is 1-butene for (A), iso-buten for (B) and 2-butene for (C), respectively and also the vapors include the small amount of both ethylene with a minute amount of methane and pro-pylene. Accordingly, the pyrolysis of surface groups is considered to take place in these temperature ranges; (5) since the same trend of pyrolysis curves and the same constituents of vapors evolved were observed for both (C) and (D), it would be considered to be no effect of the asymmetry of surface groups on the pyrolysis; (6) these results could be reasonably explained through the mechanism where the reaction, ?? proceed on the primary reaction of their pyrolysis and the alkyl radical, R thus formed could decompose into olefines, (7) the increase of either methan, ethylene or propylene and the decrease of 2-butene were observed in the products of pyrolysis for (C) and (D) at higher temperature than 650°C and furthermore the formation of 1, 3-butadiene was newly observed. This indicates that the reactions between 2-butene and methyl radical which are formed on the primary step proceeds as the secondary reaction of pyrolysis. 1) Studies on the Pyrolysis of the Esterified Silica Gels through the Gas chromatograph-Quadrupole Mass Spectrometer 11. Silica Gels surface-treated with Butanols.

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The mechanical strength of pellets of MoO₃-CoO-Al₂O₃ catalyst was measured and the results obtained are as follows:
(1) The mechanical strength of pellets depends on the MoO₃ content, CoO content and the calcination temperature.
(2) The MoO₃ content shows little influence on the mechanical strength.
(3) The CoO content up to 2% increases the strength, this being almost constant in further addition of Coo.
(4) The calcination temperature has a large effect upon the mechanical strength. The pellets, whose calcination temperature is 450°Cor 600°C, have maximum strength, unless they contain MoO3 above 20%.
The effect of the calcination temperature on the mechanical strength can be explained by the solid state reactions which occur between three oxides during calcination.

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