HUMID ATMOSPHERE INDUCED PROCESSES OF HYDROGEN FORMATION AND EMBRITTLEMENT OF Sn-Al EUTECTIC

摘要

1. The irreversible brittleness of the Sn-Al alloy in water vapor is connected with the degradation of phase boundary adhesion due to accumulation of hydrogen and formation of oxidized layers on the phase boundaries. 2. The penetration of hydrogen and its accumulation in the bulk of alloy is because of the low energy of formation of unstable tin hydride and the high energy of phase boundary (0.36 Jm~(-2)). The processes are facilitated by preliminary plastic deformation due to formation of cracks. 3. It was found that after the long time exposure in the humid atmosphere the conditions of free emission of hydrogen out of alloy are changed. Results allow to assume an opportunity of the control of processes of accumulation and emission of hydrogen.