Investment
Casting
This
is the process where the mould is China
precision machining prepared around an expendable pattern. Casting
processes in which the pattern is used only once are variously referred to as
"lost-wax" or "precision-casting" processes. In any case
they involve making a pattern of the desired form out of wax or plastics
(usually polystyrene).
The
first step in this process is the China precision machining preparation of pattern for
every casting made. To do this, molten wax which is used as the pattern
material is injected under pressure of about 2.5 MPa into a metallic die which
has the cavity of the casting to be made.
The
wax when allowed to solidify would produce the pattern. To this wax pattern, gates,
runners and any other details required are appended by applying heat.
The process has been described as the lost wax, precision casting, and
investment
casting process. The last-dimensional name
has been generally accepted to distinguish the present industrial process from
artistic, medical, and jewelry applications.
The
basic steps of the investment casting process are as follows
1.
Production of heat disposable patterns, usually in wax or plastic.
2.
Assembly of these patterns onto a gating system.
3. Investing, or covering the pattern
assembly with ceramic to produce a
monolithic mold.
4. Melting out the pattern assembly to
leave a precise mold cavity.
5.
Firing the ceramic mold to remove the last traces of the pattern material, to
fire the ceramic andChina precision machining develop the high temperature bond, and to preheat the mold
ready for casting.
6. Casting.
7.
Knock-out, cut off, and finishing.
没有评论:
发表评论