(中南大学 粉末冶金国家重点实验室,长沙 410083)
摘 要: 以AR中间相沥青为原料,在4、5、7、10 MPa下用恒压自发泡工艺制备泡沫炭生料,经炭化、石墨化处理后分别获得炭化泡沫炭和石墨化泡沫炭。采用SEM和OM观察泡沫炭的微观形貌,采用XRD分析泡沫炭的晶体结构,并测定泡沫炭的压缩强度和热导率。结果表明:随着发泡压力的升高,孔泡变得均匀,韧带片层结构变得规则有序,但发泡压力增大到一定程度后,闭孔增多,韧带有序结构变差;当发泡压力为10 MPa时,炭化和石墨化试样的压缩强度达到最大值,分别为8.16 MPa和3.42 MPa;当发泡压力为7 MPa时,石墨化试样的热导率达到最大值,61.0 W/(m∙K)。
关键字: AR中间相沥青;泡沫炭;压缩强度;热导率
properties of mesophase-pitch-derived carbon foams
(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)
Abstract:The nascent foams were prepared from AR mesophase pitch by self-foaming technology at constant pressure under foaming pressures of 4, 5, 7 and 10 MPa. Carbonized and graphitized carbon foams were formed by carbonization and graphitization. The microstructures and crystal parameters of carbon foams were characterized by SEM, OM and XRD. The compressive strength and thermal conductivity were also measured. The results show that the bubble holes distribute uniformly and the structures of the ligaments become more ordered with increasing the foaming pressure. But the number of obturated pores increases and the ligaments become more disorderly when the pressure reaches a certain degree. The maximum compressive strengths of carbonized and graphitized carbon foams are obtained at foaming pressure of 10 MPa, which are 8.19 MPa and 3.42 MPa, respectively. The thermal conductivity of graphitized carbon foam reaches the maximum value of 61.0 W/(m·K) at foaming pressure of 7 MPa.
Key words: AR mesophase pitch; carbon foam; compressive strength; thermal conductivity