本文關(guān)鍵詞：塊體納米晶鋁的力學(xué)性能及變形機理　出處：《航空材料學(xué)報》2015年03期 　論文類型：期刊論文

  更多相關(guān)文章： 納米晶 純鋁 力學(xué)性能 變形機理 高強度

【摘要】：采用霧化粉體+擠壓(Ato+Ext)、霧化粉體+熱等靜壓+擠壓(Ato+HIP+Ext)、低溫球磨+擠壓(Cryo+Ext)、低溫球磨+熱等靜壓+擠壓(Cryo+HIP+Ext)四組不同的工藝制備塊體納米晶/細(xì)晶鋁,并測定了室溫拉伸性能,分析了這些塊體材料的拉伸應(yīng)力-應(yīng)變曲線,利用透射電鏡和掃描電鏡觀察了試樣斷口附近的位錯活動及試樣的斷口形貌,討論了其變形機理和斷裂機理。研究結(jié)果表明:球磨粉體制備的塊體納米晶鋁的強度遠(yuǎn)高于霧化粉體制備的塊體超細(xì)晶鋁,四組塊體材料在拉伸過程中均不存在加工硬化現(xiàn)象;塊體超細(xì)晶鋁在拉伸過程中發(fā)生了明顯的位錯運動,對于塊體納米晶鋁,尺寸≤100nm的晶粒在拉伸過程中內(nèi)部基本不發(fā)生位錯運動;塊體超細(xì)晶鋁大部分區(qū)域發(fā)生穿晶斷裂,而塊體納米晶鋁基本發(fā)生沿晶斷裂。
[Abstract]:The atomized powder was extruded by hot isostatic pressing (ATO HIP Ext), and the low temperature ball milling was used to extrude Cryo Ext. The bulk nanocrystalline / fine-grained aluminum was prepared by four different processes of low temperature ball milling and hot isostatic extrusion (Cryo HIP Ext), and the tensile properties at room temperature were measured. The tensile stress-strain curves of these bulk materials were analyzed. The dislocation activity near the fracture surface and the fracture morphology of the samples were observed by transmission electron microscopy and scanning electron microscope. The deformation mechanism and fracture mechanism are discussed. The results show that the strength of bulk nanocrystalline aluminum prepared by ball milling powder is much higher than that of bulk ultrafine grain aluminum prepared by atomized powder. There is no work hardening phenomenon in the tensile process of the four groups of bulk materials. There is obvious dislocation movement in the tensile process of bulk ultrafine grain aluminum. For bulk nanocrystalline aluminum, there is no dislocation movement in the grain size 鈮，

本文編號：1441435