(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，合肥 230009)
摘 要: 分別在380和400 ℃下對(duì)鑄態(tài)Al-Zn-Mg-Cu合金進(jìn)行高壓扭轉(zhuǎn)實(shí)驗(yàn)，隨后對(duì)變形試樣進(jìn)行溫度為100 ℃、時(shí)間為2~10 h的時(shí)效實(shí)驗(yàn)。采用X射線衍射儀、掃描電鏡和維氏硬度分析Al-Zn-Mg-Cu合金在高壓扭轉(zhuǎn)變形過程中第二相形貌與含量變化以及時(shí)效過程中形變?cè)嚇佑捕鹊淖兓＝Y(jié)果表明：在高壓扭轉(zhuǎn)變形中，合金中第二相破碎、細(xì)化并回溶到基體中形成過飽和固溶體，第二相的回溶程度隨著溫度的升高和變形量的增加而增加。變形試樣經(jīng)100 ℃時(shí)效處理后，硬度隨時(shí)效時(shí)間的增加先上升后下降。試樣回溶程度越高，時(shí)效達(dá)到峰值所需的時(shí)間越短。
關(guān)鍵字: 新型Al-Zn-Mg-Cu合金；高壓扭轉(zhuǎn)；第二相；回溶；時(shí)效
（School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009, China）
Abstract:As-cast Al-Zn-Mg-Cu alloy was deformed by high pressure torsion at 380 ℃ and 400 ℃, respectively, and then proceeded aging treatment at 100 ℃ for 2-10 h. The changes of morphology and content of the secondary phase of Al-Zn-Mg-Cu alloy during high pressure torsion as well as the hardness of the samples deformed by high pressure torsion under aging were studied by X-ray polycrystalline diffraction, scanning electron microscopy and Vickers hardness. The results show that the secondary phase is broken and dissolved into matrix, and then form the supersaturated solid solution, the dissolution degree of the secondary phase increases with increase of the temperature and deformation. The hardness of the samples deformed by high pressure torsion increases and then decreases with the increase of the aging time during aging at 100 ℃. The higher the dissolution degree, the shorter the time reaching the peak of the samples during aging.
Key words: novel Al-Zn-Mg-Cu alloy; high pressure torsion; the secondary phase; dissolution; aging
