Jin Yuhua, Wu Bo, Lu Xuetian, Xing Yichu, Zhou Zizheng
State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, School of Materials Scienceand Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
Materials (Basel). 2020 Oct 15;13(20):4591. doi: 10.3390/ma13204591.
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.
对厚度为2毫米的1016纯铝和T2纯铜进行搅拌摩擦焊，采用上侧为铜、下侧为铝的搭接焊接形式。研究了搅拌摩擦焊焊接的1016纯铝和T2纯铜之间界面微观结构的生长情况。通过在300、350、400℃退火，揭示了铜铝搭接接头中金属间化合物（IMC）层的生长机制。搭接接头中的金属间化合物（IMC）层在退火过程中再次生长，在较低的退火温度和保温时间下，只有金属间化合物（IMC）层的原始结构生长。在较高的退火温度和保温时间下，金属间化合物（IMC）层的原始结构不再生长，在原始结构中间出现新的层状结构。在焊核区存在显微硬度的梯度变化。随着保温时间的不同，铜铝两侧的金属出现不同的软化现象。当硬度降低到一定程度后，不会随着保温时间的增加而继续降低。当退火温度为350℃和400℃时，拉伸试样的强度随保温时间的增加先增大后减小。在铜铝界面处，断裂贯穿整个金属间化合物（IMC）层。
