| 摘要 |
Moulding has a protective layer resisting corrosion and formed from raw materials similar to synthetic graphite (SG), or graphite or SG particles coated with a binder. The protective layer is formed from one or more, layers obtd. using the raw material employed for the moulding together with Si or Zr, so the atomic % of the Si or Zr increases from 0-50 atomic % from the innermost layer of the coating to the outermost layer. Pref. moulding consists of graphite, which is immersed in a bath of Si in vacuo or protective gas, and the coated moulding is then heated at 1800 degrees C to form SiC, Alternatively, the moulding may be dipped one or more times in a liq contg. powdered Si or Zr in suspension in a soln. of phenol formaldehyde contg. graphite. The moulding is then heated in an inert atmos. to 650-850 degrees C, and next to 1550-1800 degrees C. to form SiC. |
