ANOMALY OF THE WORK HARDENING OF Zn-Cu SINGLE CRYSTALS ORIENTED FOR SLIP IN SECONDARY SYSTEMS

作者：Piela K^*

来源：Archives of Metallurgy and Materials, 2011, 56(4): 1021-1027.

DOI：10.2478/v10172-011-0113-x

• zinc
• single crystal
• compression
• pyramidal slip

The copper alloyed (up to 1.5%) zinc single crystals oriented for slip in non-basal systems (orientation close to <11<(2)over bar>0>) were subjected to compression test within a range of temperatures of 77-293K. It has been stated, that Zn-Cu crystals exhibit characteristic anomalies of the thermal dependence of yield stress and of the strain hardening exponent. Both of them are related to the change in type and sequence of active non-basal slip systems: pyramidal of the 1st order (10 (1) over bar1) <<(1)over bar>(1) over bar 23> (Py-1) and pyramidal of the 2nd order (11 (2) over bar2) < <(1)over bar>(1) over bar 23 > (Py-2). The temperature anomaly of the yield stress results from the change of the slip from Py-2 systems to simultaneous slip in the Py-2 and Py-1 (Py-2 + Py-1) systems, occurring in the preyielding stage. On the other hand, sequential activation of pyramidal systems taking place in advanced plastic stage (i.e. the first Py-2 and next Py-2 + Py-1systems) is responsible for temperature anomaly of strain hardening exponent. Increase in copper addition favors the activity of Py-2 systems at the expense of Py-1 slip, what leads to a drastic differences in plastic behavior of zinc single crystals.

• 出版日期2011