ISSN:
1573-9139
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Conclusions In contact with titanium-containing metals alloyed with aluminum under conditions of high temperatures (1730–1750°C) and high vacuum (2.5·10−6–3.0·10−6MPa) all of the constituent oxides of magnesia concretes using water glass are thermodynamically unstable and are reduced to the metallic liquid or gaseous phase with simultaneous formation of titanium monoxide and alumina-magnesia spinel. With an insignificant rate of evacuation through the voids of the casting molds (as the result of the presence, for example, of a large quantity of liquid phase in the voids) the metal vapors may migrate into the surface layers of the casting and cause the appearance of a defective structure. To increase the quality of castings of titanium-containing metals alloyed with aluminum in casting into molds of magnesia composition concretes using water glass it is necessary to have the minimum content in the contact working layer of the molds of oxides of iron, sodium, and silicon with a simultaneous increase in the content of Al2O3 or MgAl2O4 to retard the reaction of spinel formation at the expense of the aluminum contained in the metal being poured.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01387606
