(1. 國防科學(xué)技術(shù)大學(xué) 航天與材料工程學(xué)院, 長沙 410073；2. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用光學(xué)顯微鏡(OM)分析子彈斜侵徹7039鋁合金后彈坑周圍的組織特征，并對侵徹過程進(jìn)行數(shù)值模擬。結(jié)果表明：子彈侵徹7039鋁合金靶材后，彈坑周圍的顯微組織呈現(xiàn)有規(guī)律的特征；當(dāng)絕熱軟化作用較弱時，彈坑周圍出現(xiàn)絕熱剪切帶和裂紋；且隨著熱軟化的加強，絕熱剪切帶聚合成較寬的層疊剪切變形帶，緊鄰的晶粒嚴(yán)重變形產(chǎn)生扭曲帶，侵徹末期組織中形成大量的變形顯微帶。采用Largrange描述的Johnson-Cook本構(gòu)模型能夠有效地模擬子彈斜沖擊侵徹7039鋁合金靶材的過程。
關(guān)鍵字: 7039鋁合金；侵徹；Johnson-Cook本構(gòu)模型；顯微組織
7039 aluminum alloy target during impact penetration
（1. School of Aerospace and Materials Engineering,
National University of Defense Technology, Changsha 410073, China;
2. School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:7039 aluminum alloy target was obliquely penetrated. The microstructure character around the crater was investigated by optical microscopy (OM). A numerical modeling during the impact penetration was established. The results show that, with the bullet penetrating into the 7039 aluminum alloy, the microstructure character around the crater is regular. When the adiabatic softening is insignificant, the adiabatic shear bands (ASB) and cracks around the crater are found. When the adiabatic softening is increased, the adiabatic shear bands coalesce into a wider overlapping shear deformation band, and the adjacent grains are deformed seriously, resulting in a lot of contorted bands. At the end of the penetration process, there are a lot of microbands. The process of bullet oblique impact penetration into the 7039 aluminum alloy can be simulated effectively using Johnson-Cook constitutive model described by Largrane.
Key words: 7039 aluminum alloy; penetration; Johnson-Cook constitutive model; microstructure
