往復鐓擠2A66鋁鋰合金室溫拉伸性能及韌化機制

往復鐓擠2A66鋁鋰合金室溫拉伸性能及韌化機制Room Temperature Tensile Mechanical Property and Toughening Mechanism of 2A66 Al-Li Alloy Processed by Repetitive Upsetting and Extrusion

利用電子衍射背散射、透射電子顯微觀察、掃描電鏡觀察和室溫拉伸試驗對往復鐓擠不同變形道次的2A66合金的組織和力學性能進行了檢測和分析.結(jié)果表明，往復鐓擠可以有效細化2A66鋁鋰合金組織，使組織更加均勻.隨著往復鐓擠變形道次增加，2A66鋁鋰合金中高密度位錯逐漸向位錯墻和亞晶界轉(zhuǎn)變，粗大的第二相分布更均勻，彌散的β′相有部分回溶到2A66鋁鋰合金基體中.往復鐓擠變形后2A66鋁鋰合金的塑性大幅提高，強度略有下降，其韌化主要是位錯組態(tài)的變化、粗大的θ′ 相的均勻和細化以及彌散的β′相部分回溶的結(jié)果。

Repetitive upsetting and extrusion (RUE) was firstly carried out on 2A66 Al-Li alloy. Electron back-scatter diffraction (EBSD), transmission electron microscopy (TEM), scan electron microscopy (SEM), and room temperature tensile testing were then performed to investigate the microstructure characteristics and mechanical properties of 2A66 Al-Li alloy. The results showed that RUE was effective in refining the microstructure of 2A66 Al-Li alloy. With the increase of RUE pass numbers, high density dislocations in 2A66 Al-Li alloy gradually transformed to dislocation walls and subgrain boundaries, distribution of large second phase (θ′) became more homogenous, and a part of β′ dispersion dissolved into the aluminum-lithium alloy matrix. After RUE processing, the ductility improved greatly with a modest reduction in strengthening, as the toughening of the alloy was mainly attributed to the change of dislocation, the homogeneity and fragment of θ′ phase, and the dissolution of β′ dispersion.

全文下載：https://pan.baidu.com/s/1geT1riV