Joining phenomena and joint strength of friction welded joint between pure aluminium and low carbon steel
Joining phenomena and joint strength of friction welded joint between pure aluminium and low carbon steel
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DOI：
10.1179/136217109x425856
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发表时间：
2009-07
影响因子：
3.3
通讯作者：
M. Kimura;H. Ishii;M. Kusaka;K. Kaizu;A. Fuji
中科院分区：
文献类型：
--
作者：
M. Kimura;H. Ishii;M. Kusaka;K. Kaizu;A. Fuji
本文介绍了纯铝(P-Al)与低碳钢摩擦焊接头的连接现象和接头强度。当摩擦压力为30 Mpa，摩擦速度为27·5 S−1时，接头在P-Al母材处发生镦粗变形。P-Al在低碳钢一侧转移到焊缝界面的半径区，然后向整个焊缝界面转移。当摩擦时间为0.9 S时，即刚过摩擦力矩的初始峰值时，接头效率为∼的93%，P-Al侧断裂。该接头在焊接界面处没有金属间化合物。然后，随着摩擦时间的增加，关节效率略有下降。当摩擦时间为2.0 S时，接头界面周边有少量金属间化合物，当摩擦时间为0.9 S时，接头效率随锻造压力的增加而降低，接头均在P-Al侧断裂。虽然在90 Mpa锻造压力下，接头几乎没有软化区，但接头效率达到∼的83%。为了弄清接头效率下降的原因，研究了P-Al母材的室温拉伸强度，并在不同的压缩应力和温度下进行了拉伸试验。在任何温度下，P-Al母材的抗拉强度都随着压应力的增加而降低。因此，接头没有达到100%的接头效率的事实是由于包辛格效应降低了P-Al母材的抗拉强度。为了获得更高的接头效率和P-Al侧的断裂，接头应在没有较高锻造压力的情况下进行，并在摩擦扭矩达到初始峰值的摩擦时间内进行。
This paper describes the joining phenomena and joint strength of friction welded joints between pure aluminium (P-Al) and low carbon steel friction welds. When the joint was made at a friction pressure of 30 MPa with a friction speed of 27·5 s−1, the upsetting (deformation) occurred at the P-Al base metal. P-Al transferred to the half radius region of the weld interface on the low carbon steel side, and then it transferred toward the entire weld interface. When the joint was made at a friction time of 0·9 s, i.e. just after the initial peak of the friction torque, it had ∼93% joint efficiency and fractured on the P-Al side. This joint had no intermetallic compound at the weld interface. Then, the joint efficiency slightly decreased with increasing friction time. The joint had a small amount of intermetallic compound at the peripheral region of the weld interface when it was made at a friction time of 2·0 s. When the joint was made at a friction time of 0·9 s, the joint efficiency decreased with increasing forge pressure, and all joints were fractured at the P-Al side. Although the joint by forge pressure of 90 MPa had hardly softened region, it had ∼83% joint efficiency. To clarify the fact of decreasing joint efficiency, the tensile strength of the P-Al base metal at room temperature was investigated, and the tensile test was carried out after various compression stresses and temperatures. The tensile strength of the P-Al base metal has decreased with increasing compression stress at any temperature. Hence, the fact that the joint did not achieve 100% joint efficiency was due to the decrease in the tensile strength of the P-Al base metal by the Bauschinger effect. To obtain higher joint efficiency and fracture on the P-Al side, the joint should be made without higher forge pressure, and with the friction time at which the friction torque reaches the initial peak.