Forming limits and interface damage behavior of different acting surfaces on TA2/Q235B composite plate

The Nakazima method was applied to performing bulging experiments of annealed TA2 pure titanium/ Q235B carbon steel composite plate samples with different sizes. The effects of acting surfaces on forming limits and interface damage behavior of TA2/Q235B composite plate were investigated. It is found that when the steel contacts with the concave die, the bulging height and forming limit of the composite plate increase due to the different contact materials, coordination deformation ability of the interface, and strain state. The bulging height of the R140 specimen reaches the maximum value (46.17 mm), and the thickness reduction and interfacial crack of the R60 and R180 specimens in three directions are larger. In addition, due to the difference in hardness and tensile stress, all horizontal and inclined holes in both groups extend toward the pure titanium.