(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 中南大學 有色金屬材料科學與工程教育部重點實驗室，長沙 410083)
摘 要: 采用硬度測試、室溫拉伸試驗、掃描電鏡(SEM)、透射電鏡(TEM)和X射線衍射(XRD)等方法研究時效Al-Cu合金固溶態(tài)、含θ″相試樣、含θ′相試樣和含θ相試樣在強變形誘導析出相低溫回溶過程中的顯微組織和力學性能。結果表明：在室溫下多向壓縮(MAC)變形過程中，隨著等效應變的增加，含θ″相試樣和含θ′相試樣的強度和塑性都顯著提高。此外，4種試樣的硬度雖然總體上升高，但含θ″相試樣和含θ′相試樣的硬度在升高過程中出現(xiàn)了一個低谷，與含θ″相試樣和含θ′相試樣在變形的過程中發(fā)生了明顯的析出相回溶有關。說明強變形誘導析出相回溶現(xiàn)象在保證強度得到提高的同時，緩解加工硬化引起的脆性，改善塑性。
關鍵字: Al-Cu合金；強塑性變形；析出相回溶；力學性能
mechanical properties of Al-Cu alloy
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China）
Abstract:The microstructure and mechanical properties of solution treatment aged Al-Cu alloys, containing θ″, θ′ and θ phases samples severely deformed by repetitive multi-axial compression (MAC) at ambient temperature were investigated by hardness test, tensile test, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffractometry (XRD). The experiment results show that, during the MAC processing, both the strength and ductility of the containing θ″ and θ′ phases specimens increase with increasing the strain. The hardness values of four specimens gradually increase during MAC, the hardness values of specimens containing θ″ and θ′ phases show an ephemeral decrease, which overall increase after MAC. These two unusual phenomena can be ascribed to the profound re-dissolution of θ" and θ′ phases induced by severe plastic deformation. The ductility of severe plastic deformation (SPD) materials is considerably improved due to the re-dissolution of precipitated phases with guaranted amelioration of strength.
Key words: Al-Cu alloy; severe plastic deformation; re-dissolution of precipitated phases; mechanical property
