炭化温度对煤矸石增强泡沫炭材料力学性能的影响

Effects of Carbonization Temperature on the Mechanical Properties of Gangue-reinforced Carbon Foams

以酚醛树脂为基体前躯体,以煤矸石为添加剂,通过化学发泡、固化及炭化工艺制备煤矸石增强酚醛树脂基泡沫炭材料,采用SEM、XRD、电子万能试验机等手段对材料的形貌、物相和力学性能进行表征,研究了炭化温度对其力学性能的影响。结果表明,当炭化温度为1400℃时,泡沫炭的孔洞较为完整,呈圆形或椭圆形,当温度超过1400℃时,孔壁变得粗糙,边沿出现裂纹。当温度由1100℃升高至1250℃开始出现莫来石物相,并随着温度的进一步升高莫来石含量逐渐增多。随着温度从1100℃升高到1550℃,该泡沫炭材料的压缩强度表现出升高趋势。

Gangue-reinforced carbon foams were prepared by chemical foaming and followed by carbonization with phenolic resin as precursor and coal gangue as additive in this paper. The surface mor- phology, phase structure, and mechanical properties of the carbon foams were investigated by scanning electronic microscope, X-ray diffractorneter and electronic universal testing machine, respectively. The re- suits show that the voids are integrated, being a round or void in shape when the carbonization tempera- ture is about 1400 ℃. When the temperature goes up over 1400 ℃, the ceil wall becomes rougher and cracks around the voids occur. The micrographs of sample with lower density which carbonized at 1400 ℃ display larger diameter of foam cells. Mullite phase begins to appear at 1250 ℃ and its content increases with increasing the carbonization temperature, which is helpful to improve the mechanical properties of carbon foams. The crush strength shows an increasing trend as a whole with temperature in- creases from 1100 ℃ to 1550 ℃. Nevertheless, the carbon foam with carbonization temperature of 1400 ℃ shows a relative low ultimate crush strength, resulting from its low bulk density and micro-defects such as dislocations and microcracks.