7055铝合金厚板的淬透性

摘要

The hardenability of a 7055 aluminum alloy plate was studied by end quenching test, the microstructure was investigated by transmission electron microscopy. The results show that the hardened depth is about 45 mm for the plate and the corresponding cooling rate is about 230 'C/min. With decreasing the cooling rate, the number and size of quench-induced equilibrium phase increase, the number of yj strengthening precipitates decreases and the width of precipitate free zone near grain boundaries increases. In the range of the studied cooling rates, the relationships among the hardness, width of precipitate free zone near grain boundaries and logarithm of cooling rate are linear.%通过末端淬火的方法研究7055铝合金厚板的淬透性,采用透射电子显微镜对微观组织进行分析.结果表明:该合金板材的淬透深度可达45 mm,使其淬透的冷却速率需大于230℃/min；随着冷却速率的减小,淬火过程析出平衡相的数量和尺寸增加,时效后析出的η'沉淀强化相的数量减少,晶界无沉淀析出带宽度增加;在所研究的冷却速率范围内,时效后铝合金板材的硬度、晶界无沉淀析出带宽度与冷却速率的对数均呈线性关系.