(1. 南京理工大學(xué) 材料科學(xué)與工程系，南京 210094；
2. 中國兵器科學(xué)研究院 寧波分院 輕質(zhì)材料研究所，寧波 315103)
摘 要: 對AZ31B/7075爆炸復(fù)合材料進行220 ℃以下低溫退火。用Axiover 40 MAT型光學(xué)顯微鏡、Quanta200型掃描電鏡、EDAX能譜儀及INSTRON 3367型力學(xué)性能試驗機對復(fù)合界面結(jié)合區(qū)進行金相組織觀察、成分線掃描以及剪切強度測試，研究復(fù)合界面結(jié)合區(qū)的低溫退火演化機制。結(jié)果表明：隨著加熱溫度的升高和保溫時間的延長，在結(jié)合區(qū)鎂合金發(fā)生回復(fù)、再結(jié)晶和晶粒長大，爆炸形成的絕熱剪切帶逐漸消失；原清晰的復(fù)合界面轉(zhuǎn)變?yōu)榫哂幸欢ê穸鹊挠涉V、鋁互擴散形成的擴散層，擴散層組織結(jié)構(gòu)由以固溶體為主逐漸轉(zhuǎn)變?yōu)橐越饘匍g化合物為主，界面剪切斷口由韌性斷裂轉(zhuǎn)變?yōu)榇嘈詳嗔眩粡?fù)合界面剪切強度取決于擴散層的組織結(jié)構(gòu)，當(dāng)擴散層組織以固溶體為主時，適當(dāng)?shù)募訜峥僧a(chǎn)生固溶強化而提高界面剪切強度，當(dāng)擴散層組織以金屬間化合物為主時，將降低界面剪切強度。
關(guān)鍵字: 鋁合金/鎂合金復(fù)合材料；AZ31B/7075復(fù)合材料；爆炸復(fù)合；界面演化；擴散層；絕熱剪切帶；剪切強度
alloy explosive composite plates after low temperature annealing
（1. Department of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
2. Lightweight Materials Institute, Ningbo Branch, China Academy of Ordnance Science, Ningbo 315103, China）
Abstract:The magnesium alloy (AZ31B)/aluminum alloy (Al7075) explosive composite plates were annealed at temperature below 220 ℃. The microstructure, elemental distribution and shear strength of the interface were studied with Axiover 40 MAT optical microscope, Quanta200 scanning electron microscope, EDAX energy dispersive spectrometer and INSTRON 3367 mechanical properties testing machine, respectively. The interface evolution due to low-temperature annealing was discussed. The results show that the recovery, recrystallization and grain growth of magnesium alloy at the binding region occur with increasing the heating temperature and prolonging the holding time, and the explosive adiabatic shear bands gradually disappear. The magnesium and aluminum inter-diffusion layers are formed instead of the original sharp composite interface, and the dominant components in the diffusion layer are gradually changed from solid solution into intermetallic compounds. At the same time, the characteristics of the interfacial shear fracture change from ductile to brittle fracture. The composite interfacial shear strength depends on the structure of the diffusion layer. When the structure of the diffusion layer is dominated by solid solution, the interfacial shear strength will be enhanced by proper heat treatment because of the solid solution strengthening. However, the interfacial shear strength is decreased by heating when the diffusion layer structure is dominated by intermetallic compounds.
Key words: Al/Mg composite; AZ31B/7075 composite explosive recombination; interface evolution; diffusion layer; adiabatic shear bands; shear strength
