For the sintered WC-Co alloys of different microstructure, domain size and root mean squared strain of the WC phase and residual stress in the WC and Co phases were measured on the ground and annealed surfaces by means of X-ray diffraction method. With varying of the microstructure the root mean squared strain and the domain size in the ground surface changed in a given range. The root mean squared strain decreased linearly with an increase of annealing temperature and settled down to about 1.4×10^-3 at a given rate, independent of the microstructure. The recrystallization temperature of WC phase in the alloys lowered with an increase of the Co-content between 800 and 1000°C, while the hot-pressed WC recrystalized at 1200°C. The maximum residual stress of about 2.5 GPa in the WC phase in ground surface, was found in a fine grained WC-6wt%Co alloy. The residual stress was almost released by removing Co from the surface layer or by annealing at 800°C, which was considerably lower than the annealing temperature of (1000-1200°C) for stress-relief in the hot-pressed WC.

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Mechanical properties such as transverse-rupture strength and plastic deformation of WC-Ni and WC-fl-Ni alloys with or without additional carbides were studied mainly at 873-1273K in comparison with Co-bonded WC base alloys.
It was found that Ni-bonded alloys showed generally a lower strength and larger plastic deformation than those of Co-bonded alloys, but this tendency became smaller in f contained alloys with increasing test temperature and decreasing carbon content. It was also found that the addition of Cr₃C₂ was most effective for improving the mechanical properties of Ni-bonded WC base alloys.

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The high temperature bend-deformation characteristics of TiC-Mo₂C-(TiN)-Ni cermets were studied at 873-1273K in relation to the carbon content. It was found that the plastic deformation of the cermets began to take place at about 873K, and it was suppressed with higher carbon content in the temperature range up to about 1073K; but at the higher temperature the effect of carbon content was reversed. The TiN contained cermet showed a smaller plastic deformation than the conventional cermets independently of test temperatures and carbon contents. The effect of carbon content in the cermets was attributed to the variation in the carbide grain size which is a function of carbon contents.

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Crystallization of a SrO-B₂O₃-SiO₂-Fe₂O₃ glass was investigated to elucidate the precipitation process of SrFe₁₂O₁₉ from the glass matrix.
The results obtained are as follows; an unidentified crystal phase, X-phase, precipitates by heating the glass in the temperature range from T_g (546°C) to 750°C. The X-ray diffraction lines of the X-phase are well indexed with assuming a cubic unit cell with α=7.584Å. In the temperature range from 650°C to 750°C, 4SrO⋅B₂O₃⋅SiO₂ precipitates in the vicinity of the glass surface and gradually grows toward the inside of the glass.
SrFe₁₂O₁₉ co-precipitates with 4SrO⋅B₂O₃⋅SiO₂ in the temperature range from 750°C to 850°C. 4SrO⋅B₂O₃⋅SiO₂ has crystallized rapidly in the whole region of the glass and no X-phase is observed in that temperature range. The amount of SrFe₁₂O₁₉ with heating time changes relatively in the same manner as that of 4SrO⋅B₂O₃⋅SiO₂. Based on these results, hexagonal platelets of SrFe₁₂O₁₉ with a dimension of%cong; 0.3μm are obtained as a precipitate from the glass by the heat-treatment at 800°C for 5 hr.

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During sintering of porous compacts of iron-lead-copper mixed powders, the liquid lead which generated over the melting point of lead disolves the copper particles and the liquid of lead-copper spreads into inherent fine voids in the compact about 700°C. As the consequence, new coarse pores are formed at the original location of the lead particles and this type of residual pore is called "melt-off pore".

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