Initiation and Suppression of Crack Propagation during Magnesium Alloy Rolling

Abstract

The conventional rolling of magnesium alloy with a single pass and large reduction will cause severe edge cracking. The sheet without cracks can be achieved by limited width rolling. The microstructure evolution of the sheet with cracks after conventional rolling and the sheet without cracks after limited width rolling is explored, and an effective mechanism for solving edge cracks is proposed. Conventional rolling can fully develop twin evolution due to high deformation, and three stages of twinning evolution can be observed and the secondary twins easily become the nucleation points of micro cracks, resulting in a large number of cracks propagating along the twin lamellae. Cracks terminate at dislocation accumulation because the accumulation of a large number of dislocations can hinder propagation. Dislocation shearing of twins to eliminate the high localization caused by twins and induce the tensile twins to weaken the basal surface texture provides an effective plastic deformation mechanism of crack inhibition, which is useful for expanding the engineering application of magnesium alloy rolled sheets.

Artificial neural network–modified heat transfer model for furnace coil rolling of magnesium alloy plate

“…The ductility of the alloy increases significantly at high temperatures due to dynamic recovery, continuous dynamic recrystallization, grain boundary slip and activation of additional slip systems. The cracks are occurred on the edge when the plate is further rolled, which leads to the decrease of the yield of the Mg plate and the increase of the cost [9][10][11] . The deformation reduction and rolling speed are also important to the production of Mg alloy plate except for temperature in the rolling process.…”

Quasi-In-Situ Analysis of As-Rolled Microstructure of Magnesium Alloys during Annealing and Subsequent Plastic Deformation

“…Magnesium alloy sheets are usually produced by rolling [ 11 , 12 ], and various forms of products can also be prepared by secondary forming methods such as stamping, showing extremely broad application prospects. The rolling process can refine the grains, improve the structure of magnesium alloys, and significantly improve the mechanical properties of magnesium alloys [ 13 ].…”