Papers by Author: Olga Kozlova

Abstract: The effects of compressive stress and undercooling of Ga to liquid gallium penetration along grain boundaries (GBs) of aluminum were investigated. It was shown that the penetration rate does not change with the temperature if gallium is in liquid state. The effect of compressive stress applied to Al samples was demonstrated. The time to wetting of all aluminum GBs increased several orders of magnitude if the compressive stress was between 0.1 and 6 MPa. It was proved that solid-liquid transformation does not take place during penetration process.

Abstract: The kinetics of liquid Ga penetration along grain boundaries in pure Al, Al-Mn (50 ppm Mn) and Al-Ga alloys (with concentration 0.7, 1 and 3% mass. Ga) was studied. It was shown that crack-like channels filled by liquid Ga were formed along all grain boundaries. Their width was about 1-3 µm. Investigation of quenched state showed that in all samples, channels had grown with linear kinetics, and that the propagation rate depended on impurity concentration in alloys: 35µm/s for Al-Mn alloy, 14 µm/s for pure Al and 9±1 µm/s for Al with (0.7-3) % Ga alloys. The difference in penetration rates of pure Al and Al based alloys are discussed in terms of internal stress and mechanical properties.