The Influence of Severe Plastic Deformation and Subsequent Annealing on the Microstructure and Hardness of a Cu-Cr-Zr Alloy
The Influence of Severe Plastic Deformation and Subsequent Annealing on the Microstructure and Hardness of a Cu-Cr-Zr Alloy
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DOI：
10.3390/ma13102241
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发表时间：
2020-05-01
期刊：
影响因子：
3.4
通讯作者：
Gubicza, Jeno
中科院分区：
文献类型：
--
作者：
Kapoor, Garima;Kvackaj, Tibor;Gubicza, Jeno
采用等通道转角挤压(ECAP)技术，在室温(RT)条件下对Cu-1.1%Cr-0.04%Zr(wt.%)合金进行了大塑性变形(SPD)。结果表明，当道次数从1次增加到4次时，位错密度显著增加35%，而微晶尺寸减小32%。随后的RT轧制对微晶尺寸和位错密度影响不大。同时，在液氮温度下进行深冷处理可获得更高的位错密度。所有样品均含有平均尺寸为1微米的铬颗粒，随着ECAP道次的增加和ECAP后轧制的进行，铬颗粒的大小和含量没有变化。用泰勒方程可以很好地关联严重变形的铜合金样品的硬度与位错密度。在430℃空气中热处理30min，所有变形样品的位错密度显著降低，而硬度显著提高。这种明显的矛盾可以用溶质氧硬化来解释，但在退火过程中移动位错的湮灭也可能有助于硬化。
A Cu-1.1%Cr-0.04%Zr (wt.%) alloy was processed by severe plastic deformation (SPD) using the equal channel angular pressing (ECAP) technique at room temperature (RT). It was found that when the number of passes increased from one to four, the dislocation density significantly increased by 35% while the crystallite size decreased by 32%. Subsequent rolling at RT did not influence considerably the crystallite size and dislocation density. At the same time, cryorolling at liquid nitrogen temperature yielded a much higher dislocation density. All the samples contained Cr particles with an average size of 1 mu m. Both the size and fraction of the Cr particles did not change during the increase in ECAP passes and the application of rolling after ECAP. The hardness of the severely deformed Cu alloy samples can be well correlated to the dislocation density using the Taylor equation. Heat treatment at 430 degrees C for 30 min in air caused a significant reduction in the dislocation density for all the deformed samples, while the hardness considerably increased. This apparent contradiction can be explained by the solute oxygen hardening, but the annihilation of mobile dislocations during annealing may also contribute to hardening.