Synchrotron in situ studies of mechanical activation treatment and γ -radiation impact on structural-phase transitions and high-temperature synthesis parameters during the formation of γ -(TiAl) compound

In situ synchrotron studies of structure and phase formation dynamics in mechanically activated (t = 7   min, power density 40   g) and mechanically activated with subsequent irradiation by γ -quanta 60Co powder mixture (Ti   64   wt% + Al) during high-temperature synthesis by the method of thermal explosion using induction heating are described. In situ high-temperature synthesis was carried out on the created experimental complex adapted for synchrotron X-ray diffraction methods. The sequence of formation and time – temperature interval of the metastable and main phases were determined. The impact of preliminary mechanical activation and of γ -irradiation on the macrokinetic parameters of the synthesis were studied experimentally in situ. It has been established that the impact of γ -irradiation on the mechanically activated powder mixture of the composition Ti 64   wt% + Al leads to a change in the thermal parameters of combustion: the maximum synthesis temperature and the burning rate decrease. The heating rate for the non-irradiated mixture is 204.8   K   s − 1 and that for the irradiated mixture is 81.6   K   s − 1. The dependences of mass fractions of the synthesized compounds on time and temperature were calculated from the stage of preheating until completion of the thermal explosion. A single-phase equilibrium product of the composition γ -(TiAl) is formed in γ -irradiated mechanically activated mixture when the system reaches maximum tem...
Source: Journal of Synchrotron Radiation - Category: Physics Authors: Tags: mechanoactivation processing γ -irradiation powder materials titanium aluminides high-temperature synthesis experimental complex thermal explosion induction heating phase formation structure formation research papers Source Type: research
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