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The microstructures and the mechanical properties of a laser powder bed fusion (LPBF) manufactured alloy coupons that were compositionally graded with austenitic stainless steel 316 L and bronze (Cu10Sn), which are immiscible, were investigated. While the microstructure of the pure 316 L contains only columnar γ-Fe grains, the formation of the equiaxed α-Cu, with α-Fe particles embedded in them, at the grain boundaries of the γ-Fe grains was observed upon alloying with Cu10Sn, for up to 50 wt.%. In the graded alloys with > 50 wt.% Cu10Sn, the microstructure inverts and contains α-Fe particle embedded α-Cu matrix along with some scattered γ-Fe grains. The two-dimensional phase-field simulations were employed to reproduced the phase transition and microstructure evolution in different compositions, revealing that the nucleation of γ-Fe occurs synchronously with the spinodal decomposition of liquid and …