7050铝合金大型锻件微裂纹原因分析  

Cause Analysis of Microcracks in 7050 Aluminium Alloy Large Forgings

作　　者：赵芳侠 张贺全 张红梅 李江云 ZHAO Fangxia;ZHANG Hequan;ZHANG Hongmei;LI Jiangyun(Yantai Moon Intelligent Machinery Technology Co.,Ltd.,Yantai 264002;Shandong Hongshan Aviation Forging Co.,Ltd.,Yantai 265700,China)

机构地区：[1]烟台冰轮智能机械科技有限公司,山东烟台264002 [2]山东宏山航空锻造有限责任公司,山东烟台265700

出　　处：《铝加工》2024年第6期16-22,共7页Aluminium Fabrication

摘　　要：7050铝合金具有优异的力学性能,适用于制造具有高强度、高断裂韧性及耐应力和剥落腐蚀要求的主承力零件。锻件制造工艺难度高,工序复杂,在制造过程中会产生各种缺陷,如夹渣、气孔、裂纹等,严重降低了产品的合格率。对微裂纹缺陷进行观察和分析,结果表明:微裂纹产生的根本原因是铝锆中间合金未充分溶解产生了金属夹杂,该裂纹在锻造过程中进一步扩展。在7050铝合金生产中,当铝锆中间合金析出相(Al3Zr)的粒子粗大、分布不均时,凝固组织就会产生缺陷,其产生金属夹杂聚集缺陷主要是由于铝锆中间合金的大尺寸析出物(Al3Zr)的遗传。为了获得粒子细小、均匀分布的Al3Zr,应使用搅拌器搅拌,使用超声波对金属液进行处理,加快凝固的冷却速度。在原材料检验工序,加严超声探伤检查标准,增加高倍组织检查,避免带初始微裂纹缺陷的原料投入生产,造成产品报废。7050 aluminium alloy has excellent mechanical properties and is suitable for the manufacture of main load parts requiring high strength,high fracture toughness and resistance to stress and exfoliation corrosion.Forging manufacturing process is difficult,the process is complex,and in the manufacturing process there are a variety of defects,such as slag inclusion,pores,cracks,etc.,seriously reducing the qualified rate of products.The paper observed and analyzed the microcrack defects.The results show that:the fundamental cause of the microcrack is the metal inclusion caused by insufficiently dissolved aluminium-zirconium alloy,and the crack spreads further in the forging process.In the production of 7050 aluminium alloy,when the particles of aluminium-zirconium intermediate alloy precipitated phase(Al3Zr) are coarse and unevenly distributed,the defects of solidification structure will occur,the main reason for the aggregation defect of metallic inclusions is the inheritance of large size precipitates(Al3Zr) in Al-Zr alloys.In order to obtain Al3Zr with fine particles and uniform distribution,the agitator should be used to agitate the liquid metal,and the ultrasonic wave should be used to treat the liquid metal,so as to speed up the cooling rate of solidification.In the process of raw material inspection,ultrasonic inspection standards should be more strict,add microstructure examination and avoid the initial microcrack defects of raw materials into production resulting in product scrap.

关 键 词：铝合金 微裂纹 探伤 金属夹杂 

分 类 号：TG146.21[一般工业技术—材料科学与工程]