Benefits of Investment Cast vs. Sand Cast
Blowhole defect in a cast iron part.
Learm more about sand casting defects at Wikipedia.org.
For sand casting, molten alloy is poured into a sand mold at
room temperature. Any moisture in the mold produces gases/vapors resulting in
casting defects that can undermine the life of the component. Numerous types of
defects can occur during sand casting including mold erosion, metal penetration,
sand fusing to the casting, drops, run outs, scabs, swells, and burn-ons.
The investment casting process pours molten alloy into a hot,
dry ceramic shell, hence no gases are created. Hot-shell pouring ensures greater
fluidity of the molten alloy. Investment castings cool more uniformly through
the cross section. As a result, there is less residual stress and fewer cracks are
created as the molten alloy cools.
General Benefits of Investment Cast Work Trays
- Longer service life
For example, investment cast HU furnace trays typically last longer
than equivalent sand cast trays.
- Less porosity
Investment cast trays are less porous than sand cast trays. In addition to
longer life, the smooth finish drags out less oil with every quenched load.
- Dimensional precision
Investment casting provides a greater level of dimensional precision. It
is possible to make thinner, structurally sound components, with
- Lighter designs
Investment cast trays may be manufactured to tighter tolerances than sand
cast trays. It is therefore possible to design lighter-weight components. Not
only does less weight reduce acquisition costs, it may also increase the
furnace’s production rate.
- Environmental impact
Sand casting results in serious environmental pollution in the form of
sand waste. Investment casting uses wax patterns which can be mostly reclaimed