Process for manufacturing a molded article made of high density carbon

US5976697A · kind A · utility

Assignee

• Daimlerchrysler AG · US

Inventors

• Klaus-Peter Brehler · Baden-Baden, DE
• Jens Schmidt · Höflaweg, DE
• Michael Scheydecker · Nersingen, DE

Key dates

• Filing date: Jul 18, 1997
• Grant date: Nov 2, 1999
• Expiry date: Jul 18, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/30
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

The invention relates to a process for manufacturing an article of a high-density carbon. To produce an un-fired compact, binderless, self-sintering, fine-grained carbon powder, particularly carbon mesophases, with a powder density of more than 1 g/cm.sup.3, particularly more than 1.4 m/cm.sup.3, and an average grain size of between 5 and 20 .mu.m, is precompacted at a low pressure and is pressed in a mold to at a pressure of between 50 and 150 MPa, particularly at approximately 100 MPa. After pressing, the contact pressure is slowly lowered. Then, the un-fired compact is carbonized in a temperature gradient of maximally 20 K/min. The temperature is held constant at a holding temperature of between 500 and 700.degree. C. for a defined holding time and is subsequently raised to a maximal temperature of between 800 and 1,200.degree. C., particularly approximately 1,000.degree. C. Finally, the carbonized compact is graphitized at an end temperature of between 2,500-3,000.degree. C. in an inert atmosphere, preferably a noble gas and particularly preferably argon and/or nitrogen.