(1. 北京科技大學(xué) 新金屬材料國(guó)家重點(diǎn)實(shí)驗(yàn)室，北京 100083；
2. 北京科技大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083)
摘 要: 利用Gleeble−1500熱模擬試驗(yàn)機(jī)、光學(xué)顯微鏡(OM)、X射線衍射儀(XRD)、透射電鏡(TEM)和背散射衍射(EBSD)，研究變形工藝對(duì)7050鋁合金析出相顆粒的影響，以及應(yīng)變誘導(dǎo)析出顆粒對(duì)連續(xù)熱變形組織的影響。結(jié)果表明：變形可使析出相顆粒發(fā)生球化，低應(yīng)變速率促使析出相顆粒細(xì)化和再析出，高應(yīng)變速率則促使析出相顆粒回溶和粗化；在連續(xù)熱變形過(guò)程中，應(yīng)變誘導(dǎo)析出的細(xì)小球形顆粒仍大量彌散分布在合金中，尺寸略有長(zhǎng)大，并且析出相顆粒釘扎位錯(cuò)和晶界，晶內(nèi)取向差變大。變形條帶晶粒被細(xì)化，合金基體中形成大量多邊形亞結(jié)構(gòu)，這可能對(duì)鋁合金強(qiáng)度和斷裂韌性的提高產(chǎn)生積極作用。
關(guān)鍵字: 7050合金；應(yīng)變誘導(dǎo)析出；熱變形；析出相
（1. State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing,
Beijing 100083, China;
2. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The effect of deformation process on the precipitates and effect of strain-induced precipitation particles on the subsequent hot deformed microstructure of 7050 alloy were investigated by optical microscope (OM), X-ray diffractometer (XRD), transmission electron microscope (TEM) and electron backscattering diffractometer (EBSD) on a Gleeble−1500 thermo-mechanical simulator. The results indicate that the deformation can accelerate the spheroidization of the precipitates. The refinement and re-precipitation of the precipitates at low strain rate deformation, and the dissolution and coarsening of the precipitates at high strain rate deformation can be observed. A large number of small globular precipitates distribute dispersively in the alloy, and the size of the precipitates increases during the subsequent hot deformation. The precipitates can pin the dislocations and grain boundaries, and misorientation increases in the elongated grain interior. The ribbon deformed-grains are refined and many polygonal substructures form, which maybe have a positive effect to improve the strength and fracture toughness of aluminum alloys.
Key words: 7050 alloy; strain-induced precipitation; hot deformation; precipitates
