Interface Strengthening and Toughening Mechanism of Hot Rolled Multilayer TWIP/40Si2CrMo Steels

Abstract

Layered metal composites play an increasingly important role in aerospace, automotive, and nuclear energy. Compared with a single metal or alloy, the layered metal composite exhibits an excellent strong-plastic matching effect. In this paper, multilayer TWIP/40Si2CrMo steels with different hot rolling reductions were successfully fabricated by the vacuum hot rolling. The results show that the multilayer steels can improve the lower yield strength of TWIP steel and lower the fracture elongation of 40Si2CrMo steel. In addition, with the increase of the hot rolling reduction, the mechanical properties and interfacial bonding strength of multilayer steels were improved, while the size and number of interfacial oxides decrease, and the fracture mode was also changed. This shows that a higher hot rolling reduction will promote the breakage of the interface oxides and make them appear dispersed, thereby improving the bonding strength of the interface, effectively suppressing the delamination and local necking of the multilayer steel, and making the multilayer steel show a higher ability of uniform plastic deformation. At the same time, under the dual action of layer thickness scale and interface strengthening effect, the brittle layer of multilayer steel presents a multiple tunnel crack mode. It was beneficial to alleviate the stress concentration and further improve the strengthening and toughening effect of multilayer steel.

Studies on Hot-Rolling Bonding of the Al-Cu Bimetallic Composite

“…or cold conditions. These theories have been narrowed down to four: two are attributed to cold bonding [7,[10][11][12][19][20][21][22][23][24][25], they include the film theory and the energy barrier theory; and two are attributed to hot bonding [1,3,17,18], these include the theory of diffusion bonding and the theory of diffusion bonding and the joint recrystallization theory.…”

“…The discovery of new materials with special properties, against the background of resource depletion and the need to recycle existing materials, always arouses the interest of researchers [1][2][3][4][5][6][7][8][9][10][11][12][13][14] around the world. The production of light-resistant materials, which is necessary for the aeronautical, naval, energy, electrical, and electronic industries, pushes research towards the association of materials with completely different properties [15][16][17][18][19][20][21][22].…”

“…Copper's properties such as its high thermal and electrical conductivity, high modulus of elasticity, and good strength makes it widely useable for gas and water pipe devices, which allows heat transfer such as boilers, electronic circuits, and electrical components within the fields of industry: energy, aeronautical, naval, and automotive. Copper was used as a reinforcing element in the production of rolling composite materials [8,9,11,17,21,[23][24][25], through the ARB process (accumulative roll bonding) [7,[9][10][11][12][19][20][21][22][23][24][25] or hot rolling [1,2,17,18]. Along with other materials such as Ti, Sn, Mg, Fe, Nb, and Al, the properties of rolled composites have increased [3,9,15,17,21,[23][24][25].…”

“…Along with other materials such as Ti, Sn, Mg, Fe, Nb, and Al, the properties of rolled composites have increased [3,9,15,17,21,[23][24][25]. The problem with the bonding mechanism within layers of composite materials was the main subject of numerous studies [1,2,7,[9][10][11][12][15][16][17][18][19][20][21][22][23][24][25], throughout the last decades. Regarding the mechanism of the bonding of the layers, the theories were dependent on the choice of the deformation process [3,[16][17][18] (in this case rolling), which can take place through hot or cold conditions.…”

“…Regarding the mechanism of the bonding of the layers, the theories were dependent on the choice of the deformation process [3,[16][17][18] (in this case rolling), which can take place through hot or cold conditions. These theories have been narrowed down to four: two are attributed to cold bonding [7,[10][11][12][19][20][21][22][23][24][25], they include the film theory and the energy barrier theory; and two are attributed to hot bonding [1,3,17,18], these include the theory of diffusion bonding and the theory of diffusion bonding and the joint recrystallization theory.…”