LZ91镁锂合金超塑成形性研究  

Research on Superplastic Forming of LZ91 Mg-Li Alloy

作　　者：芦博昕 许慧元 刘佳佳 LU Boxin;XU Huiyuan;LIU Jiajia(AVIC Manufacturing Technology Institute,Beijing 100024,China;Aeronautical Key Laboratory for Plastic Forming Technology,Beijing 100024,China;Beijing Key Laboratory of Digital Plasticity Forming Technology and Equipment,Beijing 100024,China)

机构地区：[1]中国航空制造技术研究院,北京100024 [2]塑性成形技术航空科技重点实验室,北京100024 [3]数字化塑性成形技术与装备北京市重点实验室,北京100024

出　　处：《新技术新工艺》2024年第12期11-15,共5页New Technology & New Process

摘　　要：镁锂合金密度低,比强度高,比刚度好,可应用于航空航天、汽车医疗、军事装备等领域。拟通过对LZ91镁锂合金薄板超塑成形工艺进行研究,通过对比不同温度和应变速率下材料的超塑拉伸性能,获得LZ91超塑成形工艺参数,然后通过帽锥吹塑试验进行单层结构成形试验,获得超塑成形试验结果。结果表明,LZ91镁锂合金在330℃、3×10-4 s-1条件下可以获得较好的超塑性能,超塑拉伸延伸率达到285%,当温度达到360℃时,延伸率有所降低,为215%。通过帽锥吹塑试验发现,当温度为360℃时,帽锥吹破高度最大,为74.6 mm,此时吹破压力为0.24 MPa,随着温度升高,吹破压力逐渐降低,材料变形抗力逐渐减小。对组织分析显示,帽锥超塑成形过程中在α/β相界处产生孔洞,这主要是由于该处易产生应力集中,导致孔洞萌生。Mg-Li alloy had low density,high specific strength and good specific stiffness,which could be applied in aerospace,automotive medical,military equipment and other fields.We obtained the parameters of the superplastic forming process of LZ91by intending to study the superplastic forming process of LZ91 Mg-Li alloy thin plate and by comparing the superplastic tensile properties of the material at different temperatures and strain rates,then obtained the results of the superplastic forming experiment by carrying out a single-layer structural molding test through the cap cone blow molding test to.The results showed that LZ91 Mg-Li alloy could obtain good superplastic properties under the condition of 330℃and 3×10^(-4) s^(-1),and the superplastic tensile elongation reached 285%.The elongation decreased to 215%when the temperature reached 360℃.Through the cap cone blow molding test,it was found that when the temperature was 360℃,the cap cone blowing height was the largest 74.6 mm,at this time the blowing pressure was 0.24 MPa.With the increase in temperature,the blowing pressure was gradually reduced,and the deformation resistance of the material gradually reduced.Analysis of the organization showed that the cap cone superplastic forming process in theα/βphase boundary appeared the hole,which was mainly due to the place being easy to produce stress concentration,and resulting in the hole sprouting.

关 键 词：镁合金 镁锂合金 LZ91 超塑性 帽锥成形试验 超塑成形 

分 类 号：TG146[一般工业技术—材料科学与工程] TH162[金属学及工艺—金属材料] TP206[金属学及工艺—金属学]