Bavol O. Effect of thermal-and-pressure treatment on the structure and phase state of high-carbon Fe-Al-alloys.

Manuscript is devoted to the study of features of the structure and phase state of Fe-Al-C alloys after thermal-and-pressure and subsequent pulse laser influence. Firstly it was established that temperature increasing (1400-1850 °С) with pressure action at the same time (6-8GPa) not raised the carbon solubility into the ordered Fe3AlCх phase. The new phase of cubic diamond formation occures at considerably lower temperature (1400 °С) and pressure (6 GPa), comparatively with standard meanings during the simultaneous temperature and pressure action in Fe-Al-C alloys. It was revealed that in f.c.c. crystal lattice of ordered unstoichiomethrical Fe4-уAlуCх phase the firmness of framework of Fe atoms octahedral in wide temperature and concentration intervals provides by hybridizations of p-electrons of Al and C atoms with d-electrons of Fe atoms, also p-electrons of C atoms with s-electrons of Al atoms. It was firstly established that energy advantage of forming of the ordered Fe4-уAlуCх phase of unstoichiometrical composition (y=0,5 1; x=0,5 0,66) comparatively with the stoichiometrical Fe3AlC phase. It was revealed that it's impossible to obtain the Fe3AlC unstoichiomethrical phase with help of pulse laser action. It was firstly established that at the power 10J of laser impulse and at the duration 8 s of one impulse presence of diamond crystals in the alloy led to differential besieging of ultradispersive particles of Fe and Al oxides from plasma on the surface of the highcarbon Fe-Al alloys and from above the spherical groups by 100-300 m with nanometer carbon particle structure.