Journal of the American Ceramic Society

Iseki, T.; Yamashita, K.; Suzuki, H.

doi: 10.1111/j.1151-2916.1981.tb09541.xpmid: N/A

Two self‐bonded SiC bodies containing free Si were joined with liquid Ge at 1180°C in vacuum. Bond strength was measured by four‐point bending test in vacuum at high temperature. The join had a significant strength even above the melting point of Ge metal. Electron probe microanalysis of joint showed a liquid formation temperature of thinner interlayer was ∼1200°C.

Kaiser, Gregory A.; Halloran, John W.

doi: 10.1111/j.1151-2916.1981.tb09532.xpmid: N/A

Iron magnesium aluminate spinel and lanthanum chromite specimens are unaffected by immersion in molten K2SO4 in the absence of an electrical current, but are aggressively attacked in the presence of a direct current. Anodes are deteriorated by surface reactions, while cathodes are disintegrated due to enhanced salt penetration without gross chemical reactions.

Miyayama, Masaru; Terada, Hiroya; Yanagida, Hiroaki

doi: 10.1111/j.1151-2916.1981.tb09546.xpmid: N/A

The metastable β form of bismuth sesquioxide was obtained by doping antimony oxide. The solubility of antimony was 4 to 10 at. %in β specimens, where more than 75% of the antimony atoms were valenced at 5+.

Galasso, F. S.; Veltri, R. D.

doi: 10.1111/j.1151-2916.1981.tb09543.xpmid: N/A

This study shows that the amount ofAl2O3 needed to form high density Si3N4‐15Y2‐O3 samples can be reduced by using high surface area Si3N4 powder and high N2 overpressure (high sintering temperatures) during the sintering process. The reduction in AI2O3 content results in improved oxidation resistance of the sintered samples.

Kivlighn, Herbert D.; DeIasi, Richard

doi: 10.1111/j.1151-2916.1981.tb09538.xpmid: N/A

A conventional copper sensitized photochromic glass was subjected to three excitation intensities, 21 mW/cm2, 45 mW/cm2, and 108 mW/cm2, between 0.3 μm and 0.4 μm. The effect of glass heat treatment as well as excitation intensity on the equilibrium absorption and the darkening rates is described. Results indicated that both the equilibrium absorption and the rate of darkening increase with excitation intensity.

Gururaja, T. R.; Cross, L. E.; Newnham, R. E.

doi: 10.1111/j.1151-2916.1981.tb09537.xpmid: N/A

A new technique has been developed for poling long PZT fibers by advancing the fibers along two electrical contacts maintained at the required potential difference. Two ways of maintaining the electrical contact with the ceramic are described, leading to piezoelectric d33 coefficients of 400 to 450×10−12 C/N in poled fibers of PZT‐501A. Pre‐poled fibers can be used in fabricating ceramic‐polymer composites such as triple‐pillar configurations with piezoelectric fibers oriented in three perpendicular directions.

Wuttig, Manfred; Anderson, Harlan U.

doi: 10.1111/j.1151-2916.1981.tb09539.xpmid: N/A

The surface profile which develops in the vicinity of a grain boundary precipitate in the course of evaporation is calculated. It is shown that the presence of the grain boundary precipitate affects the profile significantly if the product of the width of the grain boundary precipitate and the ratio of the evaporation rates of the unperturbed surface and the grain boundary precipitate is larger than one.

Becher, Paul F.

doi: 10.1111/j.1151-2916.1981.tb09544.xpmid: N/A

The thermal stress resistance of aluminas is strongly influenced by the surface heat transfer coefficient (h). In liquid quenches, h, which is a function of boiling phenomena, varies with bath and sample temperature. Thus, while a 22°C water quench yields ΔTc values essentially independent of the alumina properties or correspondingly, sample thickness, t, raising the bath to 100°C leads to a strong size dependence of ΔTc (i.e. ΔTc >> ∼250°C for t<1.8 mm).

Marshall, D. B.; Lawn, B. R.

doi: 10.1111/j.1151-2916.1981.tb09535.xpmid: N/A

The effect of residual contact stresses on the dynamic fatigue response of glass surfaces containing abrasion flaws is described. Indentation fracture theory is used as a theoretical basis for analyzing the experimental data. The results highlight a general need to incorporate a residual‐stress term in the fatigue equations for failure from natural flaws.

Ando, Yoshinori; Uyeda, Ryozi

doi: 10.1111/j.1151-2916.1981.tb09540.xpmid: N/A

A new method for preparing ultrafine powder of SiC is proposed. A carbon rod is mounted vertically with a block of silicon at the bottom of the system. The apparatus is held in rarefied inert gas and heated by an electric current. The SiC produced by the heating then evaporates forming a smoke, the particles of which are β–SiC <100 nm in diam.