Evolution of interface and tensile properties in 5052 aluminum alloy/304 stainless steel rotary friction welded joint after post-weld heat treatment

摘要

The inhomogeneous properties of 5052 aluminum alloy/304 stainless steel rotary friction welded joint and the growth behavior of intermetallic compound (IMC) layer were investigated. The ultimate tensile strength (UTS) of as-welded joint in 0R location with discontinuous IMC layer reached the maximum value of 203 MPa, and that in R/2 and 3R/4 locations decreased with the increase of IMC layer thickness, but that in R/4 location was the lowest due to the initiation of crack. After post-weld heat treatment at 250 degrees C/20 min, the thickness of IMC layer remained invariant, but the UTS of entire joint increased from 153 MPa to 161.4 MPa. In addition, the difference of UTS along the radius direction decreased, which benefited the engineering application. During post-weld heat treatment at 450 degrees C, the growth of IMC layer in R/4, R/2 and 3R/4 location were faster than that in 0R location. However, the growth of IMC layer deviated from parabolic law, which was attributed to (i) a large number of dislocations, grain boundaries and storage energy in the interface, (ii) the linear growth of Fe4Al13 phase, and (iii) the effect of Cr element.