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 method for producing an article (1) having a cavity (4), in which method a mould (2) provided with a core (3) is filled with article material, the article material is hardened around the core (3) to form the article (1), and the core (3) is removed from the solidified article (1). The core (3) is made of yttria tetragonal zirconia polycristal material (Y-TZP) or partially stabilized zirconium (PSZ), and after the hardening phase the core (3) is exposed to a steam atmosphere, after which the core (3) is removed from the article (1).

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, includes pre-investment of a precursor with a diluted pre-investment ceramic plaster then applying an outer mold to the encapsulated precursor as a shell-mold.

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.

First, a supply device supplies a foamed kneaded material into a cylinder. Then, in a state in which an internal space of the cylinder is communicated with a pattern forming space of a mold, the piston disposed in the cylinder is moved toward the foamed kneaded material side while opening a gas release hole formed piercing through the piston. Then, at a timing when the piston has reached an expected position where the piston is expected to be on contacting the foamed kneaded material supplied into the cylinder, the gas release hole is closed by an open-close plug. Then, the foamed kneaded material supplied into the cylinder is pressed toward the pattern forming space side of the mold by moving the piston toward the foamed kneaded material side.

A method for producing a helical casting pattern. The method including: providing a pattern body having a longitudinal axis, a cavity extending in the direction of the longitudinal axis, and a pattern body wall that surrounds the cavity; providing a processing tool for creating a recess; arranging the pattern body and the processing tool such that the processing tool extends at least partially through the pattern body wall in the radial direction with respect to the longitudinal axis; and rotatably driving at least one of the processing tool and the pattern body about one of the longitudinal axis of the pattern body and an axis parallel thereto, relative to one another, with a relative movement between the pattern body and the processing tool in a direction parallel to the longitudinal axis being produced one of continuously or at least intermittently during or in alternation with the relative rotational movement.

A method to manufacture reticulated metal foam via a dual investment solid mold, includes pre-investment of a precursor with a diluted pre-investment ceramic plaster then investing the encapsulated precursor with a ceramic plaster.