Al-5Ti-1B加入位置对8079铝合金铸轧板组织与性能的影响

Effect of Al-5Ti-1B Adding Position on Microstructure and Mechanical Properties of 8079 Aluminum Alloy Cast-Rolled Plate

用电解铝液直接铸轧成形1050 mm×7.0 mm的8079铝合金板。借助光学显微镜、扫描电子显微镜和能谱分析仪对其微观组织进行表征,并采用拉伸试验测试了力学性能。结果表明,当晶粒细化剂Al-5Ti-1B加入到距在线净化除气去杂装置出流口10~12 cm的溜槽中时,试样晶粒粗细不均,出现明显孔洞现象,并且孔洞内部出现颗粒状夹杂物,其抗拉强度平均值为87.3 MPa,伸长率为11.0%;当Al-5Ti-1B加入到距静置炉出流口15~17cm的溜槽中时,试样晶粒细小均匀,无明显孔洞和颗粒物等,其平均抗拉强度为129.7 MPa,伸长率约为36.7%。经能谱分析发现,孔洞内部颗粒物主要由TiB颗粒和AlTi发生聚集沉淀所形成。在铸轧板生产过程中,Al-5Ti-1B加入到距静置炉出流口15~17 cm的溜槽中,可有效防止粗晶组织和夹杂物,改善铸轧板组织和性能。

The 8079 aluminum alloy plate of 1050 mm×7.0 mm was directly cast and rolled with electrolytic aluminum liquid.The micro structure was characterized by optical microscope(OM),scanning electron microscope(SEM) and energy spectrum analyzer(EDS),and its mechanical properties were tested by tensile test.The results show that when the grain refiner Al-5 Ti-1 B is added into the chute about 10-12 cm away from the outlet of the on-line purification,degassing and impurity removal device,the grain structure of the sample is uneven,obvious pinholes appear,and granular inclusions appear inside the hole.The average tensile strength is 87.3 MPa and the elongation is 11.0%.When the Al-5 Ti-1 B is added into the chute 15-17 cm away from the outlet of the static furnace,the grains of the sample are fine and uniform without obvious pinholes and inclusions.The average tensile strength is 129.7 MPa and the elongation is about 36.7%.It is found by energy spectrum analysis that the particles inside the pores are mainly formed by the aggregation and precipitation of TiBparticles and AlTi.In the production process of cast-rolled plate,Al-5 Ti-1 B is added to the chute 15-17 cm away from the outlet of the static furnace,which can effectively prevent the coarse-grained structure and inclusions,and improve the structure and performance of the cast-rolled plate.