挤出7075合金在高温下的变形行为
Tuo Ye1,2, Erli Xia1,2, Sawei Qiu1,2
1School of Intelligent Manufacturing and Mechanical Engineering, Hunan Institute of Technology, Hengyang 421002, China.
Materials (Basel, Switzerland)
|March 13, 2024
概括
这项研究研究了7075合金的热压缩行为. 较高的温度降低了强度,而较高的应变率增加了强度,因再结晶而在400°C时异构性减少.
科学领域:
- 材料科学 材料科学 材料科学
- 金工业是金工业的一个方面.
- 机械工程 机械工程
背景情况:
- 挤出的7075合金由于其加工而表现出异构性质.
- 了解高温下的变形行为对于涉及热应力应用至关重要.
研究的目的:
- 为了研究在不同温度和拉伸率下挤出7075合金的热压缩变形行为.
- 分析样品方向对机械性能和微观结构的影响.
- 阐明动态软化和异质性演变的机制.
主要方法:
- 在300°C和400°C的温度下,对7075个合金样本进行了热压缩测试,应变率从0.001到0.1s-1之间.
- 与挤出方向相对应的0°,45°和90°准备样本.
- 微结构分析使用光学显微镜 (OM) 和传输电子显微镜 (TEM),而X射线衍射 (XRD) 评估了宏观纹理.
主要成果:
- 流量应力随着温度的增加而降低,并与延展率成比例增加.
- 高温促进了动态恢复和再结晶,导致动态软化.
- 在300°C时观察到异质性,0°标本显示最高应力,45°标本显示最低应力,归因于纤维颗粒和黄铜质地.
- 在400°C时,由于再结晶,流应力在方向上变得可比.
结论:
- 热压缩显著影响7075合金的机械行为和微观结构.
- 温度和拉伸率是控制变形机制和强度的关键因素.
- 在更高的温度下进行再结晶,可以降低机械性质的异构性,从而提供更多异构性材料行为的潜力.
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