After annealing under different processes, the bonding zone of the explosive composite plate has undergone different organizational changes as described above. These changes are inevitably reflected in their mechanical properties. The test results are shown in Figure 3 to Figure 6.
Figure 3 Changes in the shear strength of stainless steel-steel (1) and titanium-steel (2) explosive clad plates with annealing temperature (explosive state)
Figure 4 The change of the shear strength of nickel-stainless steel (1) and nickel-titanium (2) explosive clad plates with annealing temperature (explosive state)
Figures 3 and 4 show the changes in the shear strength of the four explosive composite panels in the shear test. It can be seen from Figures 3 and 4 that the shear strength of the stainless steel-steel and nickel-stainless composite plates does not change much with the increase of annealing temperature. In the same test of titanium-steel and nickel-titanium composite plates, the shear strength decreases sharply with the increase of annealing temperature. The study pointed out that the mechanical properties of these two different types of composite panels in the test are so different that they are closely related to the changes in the structure of the bonding zone under the same conditions mentioned above: the former has no intermediate layer of intermetallic compound in the bonding zone, and then But there is a thick intermediate layer. The existence of the hard and brittle intermediate layer must seriously weaken the bonding strength between the base metals. Moreover, the higher the annealing temperature and the longer the holding time, the thicker the intermediate layer, and the greater their influence on the bonding strength of the bimetal.
Figure 5 Annealing on titanium-steel (a) and stainless steel-steel (b)
Influence of Microhardness Distribution in the Bonding Zone of Explosive Composite Plates
1. Before explosion 2. After explosion 3.600℃ annealing 4.800℃ annealing 5.1000℃ annealing
Figure 6 Annealing on nickel-titanium (a) and nickel-stainless steel (b) explosive recovery
The influence of microhardness distribution of plywood joint zone
1. Before explosion 2. After explosion 3.600℃ annealing 4.800℃ annealing 5.1000℃ annealing
Figures 5 and 6 show the microhardness distribution curves of the bonding zone of the above four explosive composite panels after annealing under different processes. It can be seen from the figure that the hardness in the bonding zone in the explosive state is higher than the hardness of the two materials in the original supply state, and the interface position is the highest. This is caused by the strong plastic deformation (explosive work hardening) of the metal near the interface in the bonding zone. During the annealing process, as the heating temperature rises, the hardness in the bonding zone gradually decreases due to stress relief and recrystallization. The higher the heating temperature, the greater this drop. However, when the temperature is 1000°C, there will be two situations: For metal combinations that generate intermetallic compounds in the bonding zone of titanium-steel and nickel-titanium, the hardness at the interface suddenly rises a lot; for stainless steel- For metal combinations that do not form intermetallic compounds in the bonding zone such as steel and nickel-stainless steel, the hardness at this time is generally the lowest, and is near or below the hardness of the original delivery state (the delivery state of ordinary steel may be normalized State, its hardness is higher than the annealed state).