Effect of solute concentration on Portevin-Le Chatelier effect in Al-Cu alloys

摘要

The solute concentration and precipita ted phase content in alloys were altered by solution treatment (ST) at different temperatures. A series of serrated load curves was obtained in tensile tests at a constant applied strain rate. The in fluences of solute concentration and precipitated phase content on dislocation movement were analyzed with tensile test results, and the micro-mechanism of the Portevin-LeChatelier (PLC) effect is discussed in this paper. In the tests, when ST temperature was reduced from 500℃, the amplitude of serrated flow decreased. It reached the minimum when St temperature was reduced to 300℃. On the other hand, the amplitude of serrated flow increased with ST temperature decreasing from 300 to 100℃. Experimental results show that when ST temperature is higher than 300℃, solute concentration is a governing factor to PLC effect; whereas when ST temperature is lower than 300℃, the precipitated phase content significantly affects the PLC effect.