【摘要】：通過對鋁合金圓環(huán)的縱向沖擊壓縮研究發(fā)現(xiàn),一定條件下在試件的宏觀塑性硬化階段會出現(xiàn)明顯的應力降過程。為揭示此應力降的發(fā)生機制,對潤滑、細磨、粗磨3種端面粗糙條件下,外徑、內(nèi)徑和高度比值為6∶3∶2的LY12鋁合金圓環(huán)進行系統(tǒng)的Hopkinson壓桿縱向沖擊實驗。結果表明:應力降主要發(fā)生在較大的應變和較高的應變率條件。進一步對實驗樣品的金相觀察發(fā)現(xiàn):應力降產(chǎn)生的內(nèi)在機制為絕熱剪切帶的形成和發(fā)展,此現(xiàn)象是一種動態(tài)塑性失穩(wěn)的過程。以上結果為金屬材料在沖擊條件下絕熱剪切帶產(chǎn)生的研究提供了參考。
[Abstract]:By studying the longitudinal impact compression of aluminum alloy rings, it is found that under certain conditions, obvious stress drop process will occur in the macroscopic plastic hardening stage of the specimens. In order to reveal the mechanism of the stress drop, the longitudinal impact experiments of LY12 aluminum alloy rings with 6:3:2 ratio of outer diameter, inner diameter and height were carried out under the conditions of lubrication, fine grinding and rough grinding. The results show that the stress drop mainly occurs in the larger strain and higher strain rate condition. It is found that the internal mechanism of stress drop is the formation and development of adiabatic shear band, which is a dynamic plastic instability process. The above results provide a reference for the study of adiabatic shear band generation of metallic materials under impact conditions.
【作者單位】： 中國科學技術大學中國科學院材料力學行為和設計重點實驗室;
【基金】：國家自然科學基金項目(11272304,11472264)
【分類號】：TG146.21
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本文編號：2401501