焙烧炭素材料强度与结构的关系

STRENGTH/STRUCTURE RELATIONSHIPS IN BAKED CARBON MATERIALS

把用各种骨料焦制得的市售炭电极在其焙烧温度与2500℃之间进行热处理。通过对φ60×40mm圆柱体试样作径向压缩试验,测定了它们的抗拉强度。又通过对低倍放大的入射光显微镜图象进行电脑图象分析,获得了孔隙结构参数。被检的每一种炭试样的抗拉强度均随热处理温度提高而降低。抗拉强度的变化不受任何单一孔隙结构参数变化的影响。然而,我们可以用一个关系式来精确地表示强度与结构参数的关系。该关系式最初是从冶金焦研究中推导出来的。断口金相分析表明,某些炭是因穿晶骨料碎裂而断裂,另一些炭则是由于薄弱的粘结剂—骨料界面断开而断裂。这就导致得出二个系数数值不同的强度—结构关系式。

Commercially-available electrode carbons,produced using a variety of filler cokes,were heat treated between their baking temperatures and 2500℃ Their tensile strengths were determined by diametral compression testing of 60 mm diameter by 40 mm tall cylinders. Pore structural parameters were obtained by computerized image analysis of low-magnification,incidentlight microscope images.For each carbon examined, the tensile strengths fell progressivelly with increasing heat-treatment temperature.These changes in tensile strength were not reflected by progressive changes in any individual pore structural parameter. However, strength and structural data could be related with precision by an equation originally developed from studies of metallurgical cokes. Fractograpliic analysis showed that some carbons failed by transgranular filler fracture and others by failure of a weak binder/ filler interface. This resulted in two strength/structure equations ,differing in the magnitude of their coefficients, being obtained.