석탄계 피치를 이용한 고밀도 흑연 제조 |
조광연, 김경자, 류도형, 임광현1, 김정일1, 신인철1, 임연수2, 주혁종3 |
요업기술원 나노소재응용본부 1대양산업 2명지대학교 신소재공학과 3충남대학교 고분자공학과 |
Manufacture of High Density Graphite Using Coal Tar Pitch |
Kwang-Youn Cho, Kyung-Ja Kim, Doh-Hyung Riu, Kwang-Hyun Lim1, Jung-Il Kim1, In-Cheol Shin1, Yun-Soo Lim2, Heyok-Jong Joo3 |
Division of Nano Materials Application, KICET 1Dai Yang Industrial Co. 2Division of Materials Science and Engineering, Myongji University 3Division of Polymer Science & Engineering, Chungnam University |
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ABSTRACT |
Graphite has hexagonal closed packing structure with two bonding characteristics; (1) van der waals bonding between c axis, and (2) covalent bonding in the a and b axis. The weak van der waals bonds cause self-lubricant property, and the strong covalent bonds cause excellent electric and thermal conductivity. Furthermore, graphite is chemically very inert because of the material composed of only carbon elements. Thus, graphite is very useful for mechanical sealing materials. However, Graphite have porous microstructure because starting materials of graphite produce many volatile during the manufacturing processes. This causes low density of graphite, which is unsuitable for the mechanical sealing materials. Thus, further impregnation process is generally needed to enhance the graphite density. In this work, high density graphite is prepared with the principle of densification when coke and pitch binder, prepared from thermal treatment of coal tar pitch, become dehydrogenation during graphitization or carbonization. |
Key words:
Graphite, Mechanical seal, Densification, Cokes, Pitch binder |
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