以纳米Cr2O3和纳米碳黑为原料,采用碳热还原法制备纳米碳化铬(Cr3C2)粉末。采用XRD、SEM和TEM等测试手段对反应产物进行表征。结果表明:当碳含量为28%(质量分数)、反应温度为1 100℃及保温时间为1 h时,反应产物为单一的Cr3C2,平均晶粒尺寸为25.6 nm;反应产物分散较好且颗粒呈球形或类球形,无明显团聚现象,颗粒尺寸在30 nm左右;试样表面主要由Cr、C和O这3种元素组成,O 1s谱主要包括3个峰(Oa,Oh和Od),分别对应于O、OH和Cr2O3;C 1s谱主要包含4个峰(Cf,Cc,Cd和Ce),分别对应污染碳、碳化铬(Cr3C2)及其他类型的碳化铬Cr3C2 x(0≤x≤0.5)。
The carbon thermal reduction method was used to synthesize chromium carbide(Cr3C2) nanopowders using nanometer Cr2O3 and nanometer carbon black as raw materials.The products were characterized by XRD,SEM and TEM.The results show that the powders with the single phase of Cr3C2 can be synthesized under the conditions of 28% C(mass fraction),1 100℃,1 h,and the average crystallite size is 25.6 nm.The powders show good dispersion and are mainly composed of spherical or near-spherical particles with a mean diameter of about 30 nm,and they have no obvious agglomerating phenomenon.The surface of the specimen mainly consists of Cr,C and O three species elements.The XPS spectrum of O 1s mainly consists of three peaks(Oa,Oh and Od),which are considered to be due to O-,OH-and Cr2O3,separately.The spectrum of C1s mainly contains four peaks(Cf,Cc,Cd and Ce),which are ascribed to the contaminated carbon,Cr3C2 and other chromium carbides(Cr3C2-x,0≤x≤0.5),separately.