液相カーボンコーティングによるステンレス鋼粒子の流動性向上

抄録

A uniform carbon coating was applied to stainless steel (SUS316L) particles by liquid-phase carbon coating using soluble carbon material. The resulting carbon-coated stainless steel particles have improved powder flowability, especially angle of repose and spatula angle, comparing with uncoated stainless steel particles, because of the lubricating properties of the carbon layer. Carr’s flowability index was improved from 80.5 to 91. Furthermore, when sintered or melted objects were prepared from carbon-coated stainless steel particles with heating over 1250 K, the carbon coat layer reduced the oxide layer (especially chromium oxide) of the stainless steel. By heating over 1250 K, carbon coat layer removed oxygen from surface of stainless steel and also itself disappeared, therefore carbon coat layer improved purity of melted objects without changes of components and structures. The liquid-phase carbon coating improved the flowability of the stainless steel particles while not adversely affecting their sintering and melting properties.