Abstract
Friction stir welding of 1016 pure aluminum and T2 pure copper with 2 mm thickness was carried out in the form of lap welding of copper on the upper side and aluminum on the lower side. The growth of interface microstructure between 1016 pure aluminum and T2 pure copper welded by friction stir welding was studied. The growth mechanism of the intermetallic compound (IMC) layer in the Cu-Al lap joint was revealed by annealing at 300, 350, 400 °C. The intermetallic compound (IMC) layer in the lap joint grows again during annealing, and only the original structure of the intermetallic compound (IMC) layer grows at lower annealing temperature and holding time. At higher annealing temperature and holding time, the original structure of intermetallic compound (IMC) layer no longer grows, and a new layered structure appears in the middle of the original structure. There is a gradient change of microhardness in the nugget zone. With different holding times, different softening phenomena appear in the metals on both sides of copper and aluminum. When the hardness decreases to a certain extent, it will not continue to decrease with the increase of holding time. When the annealing temperature is 350 °C and 400 °C, the strength of the tensile sample increases first and then decreases with the increase of holding time. At the interface of Cu-Al, the fracture runs through the whole intermetallic compound (IMC) layer.
Highlights
Aluminum and copper are widely used in aerospace, electronics, chemical and other fields because of their excellent electrical and thermal conductivity [1,2,3,4]
This paper focuses on the analysis of the relationship between microstructure and mechanical properties of Cu-Al lap joints before and after annealing, in order to provide theoretical guidance for obtaining high-quality Al-Cu dissimilar metal friction stir welding (FSW) connections
At a fixed annealing temperature, temperature, the original structure thickness of the original intermetallic compound (IMC) layer the original structure thickness of the original intermetallic compound (IMC) layer increases with the increases with the increase of holding time, and a new layered structure appears in the middle of the increase of holding time, and a new layered structure appears in the middle of the original structure
Summary
Aluminum and copper are widely used in aerospace, electronics, chemical and other fields because of their excellent electrical and thermal conductivity [1,2,3,4]. The connection is mainly realized by the plastic flow of high-temperature metal, which effectively avoids the solidification of structural defects such as pores and inclusions caused by melting welding. Controlling the generation of intermetallic compounds and strengthening the properties of welded joints through process improvement and interface research is the research focus of dissimilar metal friction stir welding for Cu-Al at the present stage. Won-BaoLee et al [26] realized welding between pure copper and 1050 aluminum through traditional friction welding, and further analyzed the growth law of copper–aluminum intermetallic compounds in the joint and its effect on the mechanical properties of the joint after annealing. This paper focuses on the analysis of the relationship between microstructure and mechanical properties of Cu-Al lap joints before and after annealing, in order to provide theoretical guidance for obtaining high-quality Al-Cu dissimilar metal friction stir welding (FSW) connections
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
