The buoyancy transfer jig includes: a rod-shaped rod portion which is disposed extending from an outside of a pattern to an inside of a hollow portion by way of an opening portion which is formed in a foamed mold and makes the outside of the pattern and the hollow portion connected with each other, and is disposed in self hardening sand filled in the hollow portion and the opening portion; and a plate-shaped blade portion which is formed continuously with the rod portion and is disposed in the casting sand.

An opening is provided in a foam pattern, and a coating agent is applied to the opening. The coating agent applied to the opening is taken as a beam having a sectional secondary moment I (mm.sup.4), a vertical plate thickness h (mm), and a length L (mm). It is assumed that a volume of a cavity part in the foam pattern is V (mm.sup.3), a bulk density of the casting sand filling the cavity part is s (kg/mm.sup.3), a gravitational acceleration is g (mm/sec.sup.2), a density of the melt is m (kg/mm.sup.3), an angle of the opening with respect to a vertical direction is , and a transverse strength of the coating agent at the highest temperature during pouring of the melt is b (MPa). A sectional shape of the opening, the angle of the opening, and the transverse strength b of the coating agent are selected to satisfy the expression:
bI>V(ms)g{(hL/2)sin cos }.

A foam for use in a lost-foam casting process utilized in the manufacture of a component for a gas turbine engine, the foam having a void fraction less than or equal to ninety five percent, is disclosed. The foam may include a first layer comprising polymer foam having an open-cell structure and a void fraction greater than ninety five percent. A second layer, comprising adhesive, may be adhered to the first layer. A third layer comprising particulate material may be adhered to the second layer.

In the following expression, it is assumed that a thickness of a coating agent applied to a foam pattern [2] is t (mm), a diameter of a hole part [3] is D (mm), and a normal-temperature transverse strength of the dried coating agent is c (MPa). At the time of producing a casting provided with a hole having a diameter of 18 mm or smaller and a length of 1 (mm), a coating agent that satisfies the following expression is used when a solidification end time te (sec) at which solidification of a melt ends on a periphery of the hole part [3] is within a time t0 (sec) at which thermal decomposition of the coating agent ends.
c{t0/(t0te)}(1.510.sup.41.sup.2/t.sup.2+160/D.sup.2)

A method of casting a low alloy steel using a mold is disclosed. The method includes receiving the mold having a foam pattern disposed within a sand casing. The received foam pattern is coated with a permeable refractory coating and is disposed between compacted sand and the sand casing. The method further includes pouring a molten metal comprising a low alloy steel having a carbon content in a range from about 0.1 to about 0.4 percent into the mold so as to vaporize the foam pattern and remove gasification products through the permeable refractory coating, to form a low alloy steel casting. Further, the method includes removing the low alloy steel casting from the mold.

A foam for use in a lost-foam casting process utilized in the manufacture of a component for a gas turbine engine, the foam having a void fraction less than or equal to ninety five percent, is disclosed. The foam may include a first layer comprising polymer foam having an open-cell structure and a void fraction greater than ninety five percent. A second layer, comprising adhesive, may be adhered to the first layer. A third layer comprising particulate material may be adhered to the second layer.

A method to manufacture reticulated metal foam via a dual investment solid mold, includes pre-investing a precursor with a diluted pre-investment ceramic plaster to encapsulate the precursor; and investing the encapsulated precursor with a ceramic plaster within an mold of a varied cross-section. A varied cross-section mold includes a mold thickness adjacent to an outer periphery of a pattern at a top of the varied cross-section mold is between 200-500% a thickness between the outer periphery of the pattern at a base of the varied cross-section mold. A varied cross-section mold includes a trapezoidal prism shape with a pour cone in a top, the top larger than the base.

A production method for producing cast parts from metal using a sand casting mould (1). The sand casting mould (1) is produced in this case in a moulding box (2) by means of a negative-pressure moulding method. According to the invention, the sand casting mould (1), which is under negative pressure, in the moulding box (2) is first of all filled with molten metal (5). The moulding box (2) with the sand casting mould (1), which is under negative pressure therein, is then completely or partially impinged upon by a cooling fluid (4) and after, at the same time as, or before the cooling fluid impingement is opened at places with cooling fluid impingement. As a result of this, cooling fluid (4) is sucked into the sand casting mould (1) which is under negative pressure, as a result of which the solidifying cast part (3) is quenched more quickly.

A method for casting cast parts in which a casting mould is provided. The casting mould is enclosed in a housing, forming a filling space between an inner surface section of the housing and an associated outer surface section of the casting mould. The filling space is then filled with a free-flowing filling material and molten metal is poured in the casting mould. As a consequence a binder of the mould material begins to vaporise and combust disintegrating the casting mould. During the filling of the filling space, the filling material has a minimum temperature, starting out from which the temperature of the filling material rises, to beyond a boundary temperature at which the vaporising binder ignites and combusts.

A method to manufacture reticulated metal foam via a dual investment solid mold, includes pre-investing a precursor with a diluted pre-investment ceramic plaster to encapsulate the precursor; and investing the encapsulated precursor with a ceramic plaster within an mold of a varied cross-section. A varied cross-section mold includes a mold thickness adjacent to an outer periphery of a pattern at a top of the varied cross-section mold is between 200-500% a thickness between the outer periphery of the pattern at a base of the varied cross-section mold. A varied cross-section mold includes a trapezoidal prism shape with a pour cone in a top, the top larger than the base.