Aspects Of The Formation Of Layered Composites Of Ti-TiAl3 | Mekhanika | kompozitsionnykh | materialov i konstruktsii
> Volume 22 > №2 / 2016 / Pages: 245-253

Aspects Of The Formation Of Layered Composites Of Ti-TiAl3

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Abstract:

A review of preparation of aluminum and titanium foils surface is presented; the causes of gas emission and degassing possibilities in preparation for synthesis of intermetallic compounds are examined. We consider treatment of metal surfaces prior to diffusion bonding, which is the closest to the technology of laminated composite materials preparation. Methods and a number of pre-processing surfaces techniques are given, to be intended for cleaning surfaces and reducing gas content. Data on efficiency of additional aluminum and titanium foil processing are presented. Problem is under consideration of reducing the gas content in original foils of titanium and aluminum. Values of the diffusion coefficient of degassing aluminum and titanium foils are defined, the reasons of gassing and decontamination capabilities examined. Based on the average value of diffusion coefficient, the time length of titanium diffusion in aluminum layer is calculated. Efficiency of hydrogen desorption at a stage of preliminary aluminum foil degassing is estimated. It is shown that, in case of close contact titanium with aluminum foil with its thickness of d = 150 microns, the time about t = 20 minutes is sufficient that the concentration of titanium diffused in aluminum would become constant over its thickness. It is shown that if the pressure in vacuum furnace would be greatly lower than that corresponding to equilibrium temperature of elasticity for hydrogen adsorbed on the aluminum surface, time for its diffusion from the aluminum layer will be significantly less than the diffusion time for titanium estimated above. Recommendations are given to increase diffusion kinetics parameters while synthesis of aluminum and titanium foils and reducing porosity of the samples obtained, that leads correspondingly to the increase in their strength.

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