The Deformational Behaviour and Microstructural Evolution of Al-Sc-Zr Alloys with Different Copper Content under High Strain Rate Impact Loading

不同含銅量之Al-Sc-Zr合金在高應變速率撞擊下的變形行為與顯微結構分析

陳道星(Tao-Hsing Chen) ； 許昱凱(Yu-Kai Hsu) ； 方得華(Te-Hua Fang)

《中國機械工程學刊》 35卷6期 (2014/12) Pp. 499-506

摘要

本研究主要利用霍普金森試驗機進行材料之高應變速率下的機械性質測試（應變速率及溫度範圍分別為2.0×10^3, 4.0×10^3,6.0×10^3s_(-1),T=-150℃, 25℃,及300℃）及微觀組織觀測後，進一步瞭解不同銅元素含量、應變速率及測試溫度對Al-Sc-Zr合金的巨觀機械性質反應及析出物、晶粒細化與差排等顯微結構之影響。

並列摘要

This study investigates the dynamic mechanical property of three high strength Al-Sc-Zr alloys with different Cu content over a at temperature range of-150℃ to 300℃, and at strain rates of 2.0×10^3s_(-1), 4.0×10^3s_(-1) and 6.0×10^3s_(-1) using a Split-Hopkinson pressure bar. The effects of strain rate and temperature on the impact behaviour, evolution of the microstructure and fracture properties are studied. The results show that Al-Sc-Zr alloys with higher Cu content have greater strength. Fractographic SEM observations show that the fracture surfaces have a characteristic dimple-like structure. Observations of the microstructure show that the dislocation density increases with increasing strain rate and strain. TEM observations of the microstructure reveal that the presence of Al_3 (Sc, Zr) precipitate in the matrix and grain boundaries can retard dislocation movement and result in significant strengthening effect on the mechanical response.

並列關鍵字

copper ； Al-Sc-Zr alloy ； temperature ； strain rate effect ； dimple ； dislocation