In this paper, the microstructure of a gas-atomized steel powder pre-alloyed with aluminum (11.4 Cr, 10.0 Co, 5.7 Al, 5.1 Ni and Fe in wt pct) is characterized. The as-atomized powder contains NiAl-rich precipitates and most of the particles are covered with a thin (< 10 nm) Fe-rich oxide layer alloyed with aluminium. During the heating ramp of the sintering treatment, aluminum diffuses at the surface of the powder to grow an alumina layer which prevents sintering. When adding copper to the powder mix, however, liquid copper diffuses at the interface between steel and alumina, detaches alumina filaments from the steel and reshapes them into rounded particles. The evolution of the microstructure and the hardness are described as a function of tempering temperatures and time. Finally, the possibility of 3D printing this powder using the selective laser melting technique is investigated.

在本文中，气体雾化钢粉的微观结构与铝（11.4 Cr、10.0 Co、5.7 Al、5.1 Ni 和 Fe，重量百分比）进行了表征。雾化后的粉末含有富含 NiAl 的沉淀物，大部分颗粒都覆盖着一层薄的 (< 10 nm) 与铝合金化的富含 Fe 的氧化物层。在烧结处理的加热斜坡期间，铝在粉末表面扩散以生长防止烧结的氧化铝层。然而，当在粉末混合物中加入铜时，液态铜会在钢和氧化铝之间的界面处扩散，将氧化铝细丝从钢中分离出来，并将它们重新塑造成圆形颗粒。微观结构和硬度的演变被描述为回火温度和时间的函数。最后，