(西北工業(yè)大學(xué) 航空學(xué)院，西安 710072)
摘 要: 以99.9%的高純鋁為實(shí)驗(yàn)材料，利用等徑通道轉(zhuǎn)角擠壓技術(shù)制備超細(xì)晶鋁，研究其在77~473 K溫度范圍內(nèi)的準(zhǔn)靜態(tài)和動(dòng)態(tài)壓縮力學(xué)性能，并研究晶粒細(xì)化對(duì)純鋁應(yīng)變硬化行為及其溫度和應(yīng)變率敏感性的影響。結(jié)果表明：晶粒細(xì)化導(dǎo)致準(zhǔn)靜態(tài)壓縮時(shí)純鋁應(yīng)變硬化能力喪失，甚至在較高實(shí)驗(yàn)溫度下出現(xiàn)應(yīng)變軟化。此外，材料力學(xué)行為的溫度和應(yīng)變率敏感性也顯著升高。隨著實(shí)驗(yàn)溫度的升高，材料力學(xué)行為的應(yīng)變率敏感性顯著增大。
關(guān)鍵字: 超細(xì)晶鋁；等徑通道擠壓；力學(xué)性能；應(yīng)變率敏感性；溫度敏感性；應(yīng)變軟化
（School of Aeronautics, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:An available aluminum with a purity of more than 99.9% (mass fraction) was used to produce ultra-fine grained aluminium (UFG-Al) by equal channel angular pressing (ECAP) method. The mechanical behaviour of UFG-Al at temperatures ranging from 77 to 473 K under quasi-static and dynamic compression was investigated. The effects of grain refinement on the strain hardening behavior, temperature and strain rate sensitivities of mechanical properties of pure aluminum were studied. The grain refinement leads to the lost of stain hardening abilities, and the corresponding temperature and strain rate sensitivities also significantly increase. Meanwhile, as the temperature rises, the strain rate sensitivity of mechanical properties increases significantly.
Key words: ultra-fine grained aluminum; equal channel angular pressing; mechanical behaviours; strain rate sensitivity; temperature sensitivity; strain softening
