Due to copper's thermal conductivity, it has been accepted among many aluminum casting engineers that copper chills are preferable in areas of a casting that require high heat extraction.
The composite chill castings were produced, then three castings were poured using the same gating, risering and melt treatment but with the inclusion of the cast iron chills designed for Casting 3 in place of the composite chill package.
After all, intuition suggests that some legal rules will chill speech.
The question arises why legal rules not directed at protected speech might nevertheless chill such speech.
1 : coldness that is unpleasant but not extreme <There was a chill
in the autumn air.
Southern California's last storm brought cold air that has not yet moved eastward, thus the below-freezing wind chills
, according to Vladimir Ryshko, a meteorologist for the National Weather Service in Oxnard.
The use of chills
can improve casting soundness and fatigue strength when combined with the correct risering techniques.
Despite completely different mechanisms, both chills
and fins serve to reach the same goal: to locally increase the solidification rate at the problematic areas of a casting.
In the same way, chills
placed in a sand mold absorb the heat caused by the molten metal filling the mold.
To most iron foundries today, the value of chill
wedges in cast iron production is in their ability to provide quick and inexpensive checks of the carbon equivalent in gray iron.
Two 2 x 4-in, chills
in the cope and two 1 x 1-in, chills
in the drag were added to produce a sound casting.
This article relays the inherent advantages of fins over chills
and also discusses the results of an experiment in which aluminum was cast into horizontal plates in chemically-bonded sand molds to determine the optimum cooling fin geometry.
After extensive research modeling using copper, cast iron and die steel chills
of different thicknesses, it was concluded that within the range of chills
used in the investigation, higher heat transfer rates were obtained with thinner chills
than with thicker ones.
National Weather Service (NWS) says the wind chill
temperature is based on the rate of heat loss from exposed skin caused by wind and cold and is to give you an approximation of how cold the air feels on your body.
If the chill
is preheated equal to or slightly higher than the temperatures of the mold and core materials before being placed, conditions improve dramatically.