Deuterium penetration into the bulk of a steel ball of a ball bearing due to its rotation in vacuum

The experiments were performed to study a phenomenon of mechanically stimul ated solution of adatoms into the bulk under friction. A ball bearing with carbon chromium steel balls of 3.97 mm diameter was used for testing. An ax ial load of L = 34 N was applied per ball. After degassing the ball bearing performed a total of 23.8 X 10(3) revolutions at n = 196 rpm at deuterium pressure p = 5 X 10(-2) Torr. The same ball bearing was kept in the chamber without motion as a reference. The SIMS depth profiling of the contact sur face areas of the ball shows that deuterium concentration has the highest v alue of C-0 = 1.3 X 10(18) atoms cm(-3) at a depth of 0.1 mu m from the sur face. Then, it decreases to a background value of C-1 = 6.5 X 10(16) atoms cm(-3) at a depth less than 0.55 mu m For the reference ball, a considerabl e deuterium concentration was observed only on the surface. These results a re in a good agreement with recent computer simulation of the phenomenon. ( C) 1999 Elsevier Science B.V. All rights reserved.