【摘要】 利用表面分析技术、俄歇能谱仪(AES)和光电子化学分析仪(ESCA)研究了水雾化奥氏体不锈钢粉末在不同露点分解氨气氛中烧结时的表面反应。结果发现:烧结气氛的露点影响着颗粒之间的界面反应。与-25℃露点条件相比较,-41℃露点条件烧结可加速颗粒表面的还原反应,清除氧化物及其夹杂,非金属元素在颗粒界面的富集程度下降,增强颗粒之间的金属结合强度,提高了烧结材料的力学性能。更多还原

【Abstract】 The present paper has studied the surface reaction of water atomized 304L austenitic stainless steel powder during sintering in dissociated ammonia （D.A.） atmosphere with different dew points, -25℃ and -41℃. It has been found that dew point of D.A. atmosphere has a strong effect on surface reaction of powder particle boundaries and pore surfaces. By comparision with above two dew points, the lower the dew point is, the better the reduction effect. The concentration of non-metallic elements such as O₂, N₂, C and S on powder particle boundaries and pore surfaces of the specimen sintered in -41℃ dew point D. A. atmosphere is lower than that of the specimen sintered in -25℃ dew point D. A. atmosphere. The surface coverage of oxides and other compounds on the fracture surface of specimen sintered in-41℃ dew point D.A. atmosphere is 13% and that of the specimen sintered in —25℃ dew point D.A. atmosphere is 28%. Therefore the specimen sintered in —41℃ dew point D.A. atmosphere has higher mechanical properties than that of the specimen sintered in -25℃ dew point D. A. atmosphere. The reason is that the lower dew point of D. A. improves the surface reduction reaction更多还原