Mo元素对激光粉末床熔融Co-Cr-Fe合金组织与性能的影响

Effect of Mo Element on Microstructure and Properties of Laser Powder Bed Fusion Co-Cr-Fe Alloy

摘要:

采用Co、Cr、Fe和Mo单质元素混合粉末作为激光粉末床熔融的原材料，以原位合金化的方式制备了15Co-25Cr-(60-x)Fe-xMo(x=0~5, wt%)的成分梯度样品。研究了不同Mo含量试样的成分均匀性、相结构及微观组织。并结合实验结果与第一性原理计算，研究了Mo含量对磁性能的影响。结果表明：所有样品均实现了合金化且无孔洞或未熔颗粒等缺陷。随着Mo元素含量的增加，试样的磁性能呈现出先增加后降低的趋势。当Mo含量为3wt%时，试样具有最佳的磁性能，其矫顽力（）、剩磁（）和最大磁能积分别为26.54 kA/m、0.9 T和11.56 kJ/m³。此外，Mo的添加也提高了试样的显微硬度，15Co-25Cr-57Fe-3Mo合金的显微硬度为424HV_0.5。

Abstract:

Compositionally graded 15Co-25Cr-(60-x)Fe-xMo (x=0-5, wt%) specimens were fabricated by 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 different Mo contents were 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 achieve full alloying without defects such as porosity or un-melted particles. The magnetic properties exhibit a non-monotonic trend with increase in Mo content, initially enhancing before deteriorating. Optimal magnetic performance is obtained at the Mo content of 3wt%, yielding a coercivity () of 26.54 kA/m, a remanence () of 0.9 T, and a maximum energy product () of 11.56 kJ/m³. Additionally, Mo incorporation is found to enhance the microhardness of the alloys, with the 15Co-25Cr-57Fe-3Mo sample exhibiting a hardness of 424HV_0.5.