Method for constructing curved grain boundary in dissimilar alloy transition area through additive manufacturing

The invention relates to the field of dissimilar alloy processing, in particular to a method for constructing a bent grain boundary in a dissimilar alloy transition area through additive manufacturing, which comprises the following steps of: 1, melting a dissimilar alloy material through energy provided by a concentrated heat source to form a molten pool; secondly, the dissimilar alloy melt is driven by micro fluid force to form regular alloy component distribution, and additive manufacturing induced bending grain boundaries are achieved; the microfluid force acting effect is limited by the transverse-longitudinal ratio Dm/Wm of the molten pool, Dm is the distance from the bottom of the molten pool to the top of the base plate, and Wm is the width of the molten pool; the premise of constructing the curved grain boundary is curved alloy component distribution, and 0.25 < = Dm/Wmlt; 0.55% of the total weight; for single-layer single-track additive manufacturing, the alloying degree (DoA) is controlled, and addi