Nucleation stress for persistent slip bands in fatigued copper single crystals
1988; Elsevier BV; Volume: 101; Linguagem: Inglês
10.1016/0921-5093(88)90044-5
ISSN1873-4936
AutoresJaroslav Polák, Jan Helešic, Karel Obrtlík,
Tópico(s)Copper Interconnects and Reliability
ResumoCopper single crystals oriented for single slip were cyclically strained at a constant plastic strain amplitude up to fracture. The stress amplitude, the loop shape parameter and the average hardening coefficient were measured using a computer-controlled electrohydraulic system. The nucleation stress amplitude for persistent slip bands was found and compared with the saturation stress amplitude. The long-term steady decrease in the loop shape parameter found for all amplitudes indicates hardening within the persistent slip bands. No oscillations in the loop shape parameter before the minimum was reached and no support for avalanche-type cyclic straining were found.
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