颗粒增强2024Al复合材料的微屈服性能研究

A study on micro-yield property of a particle reinforced 2024Al matrix composite

为了明确亚微米颗粒增强铝基复合材料微塑性变形行为的规律和机制,利用微屈服强度测试和透射电镜分析,研究了亚微米级Al2O3颗粒增强2024Al复合材料的微屈服性能及尺寸稳定化热处理工艺对微屈服性能的影响.研究结果表明:复合材料的显微组织在稳定化热处理前后均呈现位错稀少的特点,有助于材料微屈服强度的提高;复合材料中尺寸细小,密集分布的S′相和亚微米颗粒本身对位错运动的有效阻碍也能改善材料的微屈服强度;时效后采用不同的冷热循环处理工艺,使得复合材料基体中S′相的尺寸和分布都发生一定的改变,进而呈现出不同的微屈服性能.

In order to understand the regularity and mechanism of microplastic deformation of submicron particle reinforced composites, the microyield property and the effect of stabilizing treatment procedures on the microyield property of submicron Al2O3 particle reinforced 2024Al composite were studied by means of microyield strength measurement and TEM analysis. The results showed that the dislocation density was low in the microstructure of submicron Al2O3p/2024Al composite before and after stabilizing treatment. This microstructural feature is favorable for microyield strength of the composite. The microyield strength of composite would also be improved by submicron Al2O3 particles and phase precipitates with small sizes and dense distribution which can impede the dislocation movement effectively. The sizes and distribution of phase precipitates were greatly changed by different thermalcold cycling treatment after aging, which has great effect on the microyield property of the composite.