基于旋轉(zhuǎn)摩擦擠壓法制備CNTs/Al復(fù)合材料的顯微組織

基于旋轉(zhuǎn)摩擦擠壓法制備CNTs/Al復(fù)合材料的顯微組織Microstructure of CNTs/2024Al composites prepared by rotational friction extrusion

采用旋轉(zhuǎn)摩擦擠壓法制備CNTs/2024Al復(fù)合材料，并利用電子背散射衍射技術(shù)對復(fù)合材料的晶體取向、晶粒尺寸、取向差分布和織構(gòu)進(jìn)行分析。結(jié)果表明：鋁基材的組織為粗大的板條狀，其平均晶粒尺寸為48.67 μm，大角度晶界含量為24.4%；經(jīng)RFE加工后，鋁基材變?yōu)閯討B(tài)再結(jié)晶后的細(xì)小等軸晶，平均晶粒尺寸減小為3.22 μm，大角度晶界含量增加至63.9%。當(dāng)CNTs含量增加至5%時，CNTs/2024Al復(fù)合材料平均晶粒尺寸減小至1.97 μm，大角度晶界含量增加至82.7%，CNTs的加入阻止復(fù)合材料的晶粒長大。經(jīng)RFE加工后，鋁基材的最大極密度由10.8降低為4.18，軋制織構(gòu)強(qiáng)度減弱；CNTs的加入對復(fù)合材料的織構(gòu)強(qiáng)度具有弱化作用。

The carbon nanotubes (CNTs) reinforced 2024 Al matrix composites were fabricated by rotational friction extrusion (RFE).The crystal orientation, grain sizes, misorientation angle distributions and texture were analyzed by electron back scatter diffraction. The results show that the microstructure of aluminum matrix is the coarse strip, the average grain size is 48.67 μm and the large angle grain boundary content is 24.4%. After RFE, the microstructure of aluminum matrix becomes the fine equiaxed crystals by dynamic recrystallization. The average grain size of the RFE aluminum matrix decreases to 3.22 μm, and the large angle grain boundaries increases to 63.9%. With the increase of CNTs content, the average grain size of the CNTs/2024Al composites is gradually reduced to 1.97 μm and the ratio of large angle grain boundaries increases to 82.7% when the content of CNTs increases to 5%. CNTs can prevent the growth of the grains in the composites. The maximum pole density of aluminum matrix decreases from 10.8 to 4.18 and the rolling texture intensity decreases. The recrystallization textures of the composites are weakened by the addition of CNTs.

全文下載：https://pan.baidu.com/s/1jIgSS78