ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The reaction kinetics between α-Ti alloys and single crystal sapphire, the phase composition and morphology of the reaction-zone, and the phase compatibility in the system Ti-Al-O were investigated as part of a study to determine the feasibility of fabricating useful Al2O3-reinforced titanium matrix composites. In the temperature range 650 to 1000° C titanium reduces Al2O3 to form a complex reaction layer consisting of two distinct zones; an inner zone adjacent to the Al2O3 of a TiO phase containing isolated particles of (Ti, Al)2O3, presumably, and an outer zone of a Ti3Al phase adjacent to the Ti matrix. The isothermal growth of the reaction layer follows a parabolic rate law. The temperature dependence of the rate constants fits an Arrhenius equation yielding activation energies of 50 to 52 kcal/mol. The high Al alloys, except Ti-6Al-2Sn-4Mo-2Zr, reacted more rapidly than pure Ti indicating that Al diffusion through the reaction zone may be the rate-limiting step.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00550662
