Chapter 25

2. Chapter 25 Casting Casting Practice • Casting Quality

3. The foundry flowsheet indicates the steps performed to produce castings and recycle scrap metal.

4. Methods of refining molten metals include protective flux coverings, bubbling insoluble gases through the melt, and vacuum degassing.

5. A sand mold is complex and consists of several components.

6. Investment casting is used to produce small, precision shapes and is achieved using a wax pattern.

7. Permanent mold casting requires a metal mold that may be reused many times.

8. The basic types of induction furnaces are the coreless and the channel (core) types.

9. The crucible furnace is extremely versatile and is generally used to handle small charges.

10. Three stages of shrinkage occur during the solidification of a casting.

11. Solidification shrinkage leads to voids and microporosityunless the casting is properly fed.

12. Alloys may have short or long freezing ranges, which influences the way they solidify.

13. Risers must be located so that the casting is completely filled and solidified.

14. Castings must be properly designed to take advantage of their unique characteristics.