In: Mechanical Engineering
question : 1
While cores increase the cost of
castings, they also provide a number of...
question : 1
While cores increase the cost of
castings, they also provide a number of distinct advantages. The
most significant is the ability to produce complex internal
passages. They can also enable the production of difficult external
features, such as undercuts, or allow the production of zero draft
walls. Cores can reduce or eliminate additional machining, reduce
the weight of a casting, and reduce or eliminate the need for
multi-piece assembly. Answer the following questions about
cores.
- The cores themselves must be produced, and generally have to be
removed from core boxes or molds. What geometric limitations might
this impose? How might these limitations be overcome?
- Cores must be positioned and supported within a mold. Discuss
some of the limitations associated with core positioning and
orientation. Consider the weight of a core, prevention of core
fracture, minimization of core deflection, and possible
buoyancy.
- Because cores are internal to the casting, adequate venting is
necessary to eliminate or minimize porosity problems. Discuss
possible features to aid in venting.
- How might core behavior vary with different materials being
cast—steel versus aluminum, for example?
- Discuss several of the reasons cores may be made from a
different material than the molding material used in the primary
mold.
- Core removal is another design concern. Discuss how several
different core making processes might perform in the area of
removal. What are some ways to assist or facilitate core
removal?