Abstract:Compositionally graded 15Co-25Cr-(60-x)Fe-xMo (x=0-5, wt.%) specimens were fabricated via laser powder bed fusion (LPBF) using blended elemental powders of Co, Cr, Fe, and Mo, employing an in-situ alloying strategy. The compositional homogeneity, phase constitution, and microstructure of the specimens with varying Mo content were systematically investigated. Furthermore, the influence of Mo content on the magnetic properties was elucidated by integrating experimental findings with first-principles calculations. The results indicate that all specimens achieved full alloying without defects such as porosity or un-melted particles. The magnetic properties exhibit a non-monotonic trend with increasing Mo content, initially enhancing before deteriorating. Optimal magnetic performance is obtained at 3 wt.% Mo, yielding a coercivity (H_c) of 26.54 kA/m, a remanence (B_r) of 0.9 T, and a maximum energy product (〖(BH)〗_max) of 11.56 kJ/m3.Additionally, Mo incorporation was found to enhance the microhardness of the alloys, with the 15Co25Cr57Fe3Mo sample exhibiting a hardness of 424 HV0.5.