The quasi-static tensile experiment was used to study the tensile mechanical properties and deformation behavior of the steel/aluminum composite plate in the strain rate range of 1×10−4~1×10−2 s−1, and the microstructure evolution and analysis of the composite interface were characterized by scanning electron microscopy. Failure mechanism. The results showed that the steel/aluminum rolling composite interface formed a transition layer with a thickness of about 8 μm and a small amount of intermetallic compounds Fe2Al5 and Fe4Al13. The strength of the composite board satisfies the law of mixing with the steel and aluminum layers. The interface has a strengthening effect but is prone to microcracks. The failure of the interface and the strain hardening of the base layer cause the stress-strain curve to fluctuate. High strain rate loading causes the interface layer to fracture sharply, and the degree of curve fluctuation increases, but the degree of interface separation of the fracture decreases. In the quasi-static stretching process, cracks are first initiated at the steel/aluminum interface, and the additional stress between the layers causes the interface cracks to grow and extend into the aluminum layer, and the steel layer subsequently necks and causes the composite plate to break and fail. Increasing the bonding strength of the
carbon steel aluminum sheet interface can improve the deformation coordination and mechanical properties of the laminated composite panel. The steel/aluminum composite board is covered with a layer of aluminum or aluminum alloy on the surface of the carbon steel substrate, and the interface between the layers forms a strong metallurgical bond. It combines the excellent properties of steel and aluminum and is a metal layered with high cost performance. Composite materials are widely used in machinery, vehicles, petrochemicals and other fields. At present, the preparation technology of
carbon steel aluminum sheets has made great progress. Rolling composite technology has become the main method for preparing steel/aluminum laminated composite materials due to its environmental friendliness, high degree of automation, and continuous production. Preparation in rolling compound
During the process, element diffusion is more likely to occur in the interface area of the steel/aluminum composite plate, which promotes the metallurgical bonding between the matrix layers, but the interface area often forms a layer of transition structure with different compositions and structures, which has an important impact on the service behavior of the composite plate. . Therefore, it is necessary to conduct in-depth research on the structure evolution law and mechanical response mechanism of the metal layered composite material, and provide an accurate model for the optimization and control of the mechanical properties of the composite plate.
Researchers have carried out a series of studies on the preparation technology and microstructure properties of
carbon steel aluminum sheets, revealing the microstructure evolution law of the composite interface. Xu Wei et al. found that the titanium/aluminum composite plate prepared by explosive welding has a wavy interface, and there are a small amount of intermetallic compounds and other island-shaped inclusions in the interface area, resulting in periodic cracks along the interface during subsequent rolling of the composite plate. Research by Liu Xinghai et al. showed that the steel/aluminum composite plate prepared by hot-rolling at a temperature above 550 ℃ will form discontinuous intermetallic compounds and microvoids in the interlayer interface zone, which restricts the interface bonding strength and bending forming of the composite plate. performance. TALEBIAN et al. found that when the annealing temperature is higher than 500 ℃, after 30 minutes of heat preservation treatment, a large number of intermetallic compounds and diffusion holes will be generated at the steel/aluminum composite interface, resulting in high brittleness and fracture separation of the steel/aluminum interface.
