摘要 |
<p>Very large tools can be cast-to-size by making a pattern of the article to be formed by the tool, laying the pattern up in a pattern box, applying a release coat and coating the pattern and box with a tough, curable tool surface layer. A small amount of epoxy filled with a thermally conductive particulate filler is cast into the pattern box before the surface layer fully cures. Relatively large chunks of thermally conductive material are added to the box which are covered with additional cast epoxy. The cure of the epoxy is controlled to effect complete cure at room temperature within a few days but never to exceed a peak cure temperature above about 70 DEG C.</p> |