| 摘要 |
The hot isostatic pressure (HIP) method for densification of a metal casting which includes surface-connected discontinuities over which a coating is applied to bridge surface openings associated with the discontinuities and to prevent pressurizing fluid penetration within such discontinuities is improved through the application of a selected type of ceramic coating. Such coating is of a material which provides a substantially gas impervious ceramic coating, preferably of a thickness in the range of about 0.003-0.01'', having a coefficient of thermal expansion matched with that of the casting surface to which it is applied as well as having the property of being viscous under the densification processing conditions at which the bond between the coating and the casting surface degrades. Upon cooling, the coating is easily removed from the surface of the densified casting. |
