5A90 Al-Li合金桁条电流自阻加热成形技术

Al-Li合金具有密度低、比强度高等优点,是实现飞行器结构减重的理想材料,在航天航空领域显示出了广阔的应用前景。先进的电加热成形技术是提高轻质合金成形性能的有效手段。通过高温拉伸实验研究了5A90 Al-Li合金的成形性能,确定了5A90 Al-Li合金的最佳成形温度为340℃。通过电流自阻加热升温实验,得到了加热5A90 Al-Li合金板材合适的电流密度为10 A·mm~(-2)。针对5A90 Al-Li合金室温成形性能差的问题,设计并制造了5A90 Al-Li合金桁条电流自阻加热成形装置,在此装置上进行了5A90 Al-Li合金桁条的电加热成形实验,得到了符合要求的桁条零件,并分析了温度、润滑条件等对成形质量的影响。这种新型的板材电流自阻加热成形工艺及装备具有较大的实际应用价值。

Current resistance heating forming technology of Al-Li alloy 5A90 stringers

Al-Li alloy with advantages of low density, high specific strength etc.is the desirable material to realize the weight loss for aircraft structure, which shows strong competitiveness and broad application prospect in the field of aerospace and aviation.The advanced electrical heating forming technology is an effective way to improve the formability of light alloy.Therefore, the formability of Al-Li alloy 5A90 was studied by high temperature tensile experiment.And the best forming temperature of Al-Li alloy 5A90 sheet is 340 ℃.Then, the appropriate current density of Al-Li alloy 5A90 sheet under heating is 10 A·mm-2, which is obtained by the current resistance heating experiment.Furthermore, the device of current resistance heating forming for Al-Li alloy 5A90 stringers was designed and produced to solve the problem of poor formability at room temperature.The Al-Li alloy 5A90 stringers were formed by the current resistance heating forming process to meet the requirements, and the influences of temperature, lubrication and other factors on the quality of Al-Li alloy 5A90 stringers were analyzed.Thus, the new current resistance heating forming process and corresponding devices for sheets have great significance in practical application.