对2024铝合金进行不同温度下的热处理, 得到了一系列具有不同溶质原子浓度的基体及析出相含量的铝合金试样. 将这些试样分别在低温(-100 ℃)和室温(25 ℃)下进行拉伸实验, 分析其锯齿幅值和临界应变随应变率的变化趋势. 结果表明, 溶质原子是 Portevin--Le Chatelier (PLC)效应的必要因素, 单纯的位错切割沉淀相不足以产生PLC效应, 只能影响PLC效应, 并且沉淀相对PLC效应的影响在中等拉伸应变率时表现明显.
It is normally accepted that the interaction among solute atoms, dislocations
and precipitate leads to Portevin--Le Chatelier (PLC) effect during the plastic
deformation of alloys. Precipitate is directly responsible for some inverse behavior of
PLC effect, such as the inversion of the temperature dependence of critical strain;
because these behaviors appear only when precipitate exist in the alloys. In this paper,
the solute concentration in matrix and the fraction of the precipitate in 2024 Al alloy
are changed by heat treatment. Subsequently, tensile experiments are conducted at
room temperature (25 ℃) and low temperature (-100 ℃) on these treated specimens.
The magnitude of serration and the critical strain of the serrated flow are analyzed and
the results show that the diffusing solute atoms are necessary for the appearance of
PLC effect while the cutting of the precipitate particles alone can not lead to this
phenomenon. The mobile dislocations will be blocked and piled up strongly in the front
of precipitate and thus precipitate will have an influence on PLC effect. This influence
is obvious during tensile tests at medium strain rate.
参考文献
| [1] | |
| [2] | |
| [3] | |
| [4] | |
| [5] | |
| [6] | |
| [7] | |
| [8] | |
| [9] | |
| [10] | |
| [11] | |
| [12] | |
| [13] | |
| [14] | |
| [15] | |
| [16] | |
| [17] | |
| [18] | |
| [19] | |
| [20] | |
| [21] | |
| [22] | |
| [23] | |
| [24] | |
| [25] | |
| [26] | |
| [27] | |
| [28] |
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