Compositional analysis of the icosahedral phase in rapidly quenched Al-Mn and Al-V alloys

The formation ranges and alloy compositions of icosahedral phases in rapidly quenched Al-Mn and Al-V alloys containing 12.5 to 25 at. pct Mn and V, respectively, were examined by X-ray diffractometry and analytical transmission electron microscopy. The icosahedral phase was found to appear in a wide range of compositions below about 23 at. pct Mn and below about 18 at. pct V, but the formation of the icosahedral single phase was limited only in the vicinity of about 22.5 at. pct Mn. The analytical solute concentration in the icosahedral phase is not always constant and increases continuously from about 17 to 23 at. pct Mn and about 18 to 21 at. pct V with increasing nominal solute concentration. Thus, the icosahedral phase in rapidly quenched Al-Mn and Al-V alloys can be approximately formulated to be Al₄Mn and A1₄V with a maximum deviation of about 3 at. pct Mn or 2 at. pct V from the stoichiometric ratio.     

Microstructure and porosity of zirconium dioxide powder compacts produced at pressures up to six GPa

Translated from Poroshkovaya Metallurgiya, No. 9(345), pp. 69–74, September, 1991.     

Compacting tungsten powders with varying particle size using hydrostatic pressure up to 5 GPa

Conclusions The density of compacts is dependent on the powder particle size and its surface condition. The predominating consolidation mechanism for powders having a particle size of less than 0.1 m is interparticle slipping, although the role of plastic deformation increases as the particle size increases. The density of very finely divided powder compacts may be increased significantly by reducing the interparticle friction of the pretreated surfaces by employing a reducing anneal or by adding a more plastic component. Consolidating a powder with a 3- to 8-m particle size can be efficiently achieved without any additional treatments.Translated from Poroshkovaya Metallurgiya, No. 4, pp. 16–20, April, 1992.