摘要
7A04铝合金是我国自行研制的超高强度铝合金,具有强度高、热处理强化效果好等特点,广泛应用于航空、航天等工业领域。但是,与其他系列的铝合金相比,7A04的挤压成形性能相对较差。针对一种具有深孔的双杯形零件,对7A04铝合金复合冷挤压工艺进行了研究。研究结果表明,热挤压棒料经380℃高温退火处理后具有良好的塑性,延伸率达到17.5%。采用计算机数值模拟和冷挤压成形实验研究相结合的方法,考察了冷挤压成形过程中的材料流动与应力分布状况,发现深孔底部附近的有效应力最大,且材料流动不均匀;当孔深大于50mm时,深孔底部附近容易出现挤压裂纹。在研究结果的基础上,制定了适宜的复合冷挤压工艺成形工艺路线,实现了零件的冷挤压成形。
7A04 aluminum alloy was a kind of high strength aluminum alloy, and widely used in industry. However, the extrudability of 7A04 aluminum alloy was relatively poor compared with other series of aluminum alloys. In this paper, the cold extrusion process of 7A04 aluminum alloy was developed for the production of a double-cup workpiece with a deep hole. It was found that the ductility of the as hot-extruded billet could be improved after annealing at 380℃. The material flow and stress distribution of the billet during cold extrusion were investigated by experiment and finite element （FE） simulation. It was noticed that the maximum stress was concentrated at the bottom of the deep hole, and the material flow in this region became difficult. Cracks were easily to form near the deep-hole bottom if the depth of hole exceeded 50 mm. Based on the experimental results, the processing route of the compound cold extrusion which was suitable for the production of the workpiece was established.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2009年第5期621-625,共5页
Chinese Journal of Rare Metals
基金
广东省科技攻关项目(2008A010300003)资助
重庆长安工业集团有限责任公司资助项目
关键词
7A04铝合金
冷挤压
组织
7A04 aluminum alloy
cold extrusion
microstructure
