Provided is a casting method using lost foam capable of forming a small highly-finished hole with a diameter of 18 mm or less and a length of 50 mm or more by casting. A casting method using lost foam of the present embodiment includes the steps of embedding, in foundry sand, a casting pattern formed by applying a mold wash with a thickness of 1 mm or more to a surface of the foam pattern, the foam pattern having a hole with a diameter of D (mm); replacing the foam pattern with molten metal by pouring the molten metal into the casting pattern and losing the foam pattern; and forming a casting having a small hole with a diameter of 18 mm or less and a length of 50 mm or more by cooling the molten metal, and the method satisfies the following formulas (0) and (1):
2<D19.7Formula (0)
c0.36+140/D.sup.2Formula (1) where c (MPa) is transverse rupture strength (bending strength) of the mold wash that is heated to decompose resin constituting the mold wash and then returned to room temperature.

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 method to manufacture reticulated metal foam via a dual investment solid mold includes pouring molten metal material into a mold while the mold is located on a chill plate. A method to manufacture reticulated metal foam includes pouring molten metal material into a mold while the mold is located on a chill plate, the chill plate configured to apply an externally driven temperature gradient in the mold so that solidification progresses from the chilled end to the non-chilled end

A method to manufacture reticulated metal foam via a dual investment solid mold includes pouring molten metal material into a mold while the mold is located on a chill plate. A method to manufacture reticulated metal foam includes pouring molten metal material into a mold while the mold is located on a chill plate, the chill plate configured to apply an externally driven temperature gradient in the mold so that solidification progresses from the chilled end to the non-chilled end.

Refractory slurry for use in coating a foam cluster to provide a foam pattern for lost foam casting is provided. The slurry includes a catalyst capable of catalyzing reactions for vaporizing the foam cluster. A foam pattern with a refractory coating including the catalyst and processes for preparing the foam pattern and using the foam pattern are also provided.

A method of manufacturing precision cast parts for vehicle exhaust systems includes fabricating a model of a product to be manufactured using a substance selected from the group consisting of a wax and a plastic, forming a first coating layer on a surface of the model using a first slurry, forming a second coating layer on the surface of the model coated with the first coating layer using a second slurry, drying the first and second coating layers to form a mold and heating the mold to remove the model, pre-heating the mold, placing the mold in a ceramic box with a top portion open, and filling an inner part of the ceramic box with ceramic balls, and producing a product by injecting a molten metal into the mold to cast the product.

A method to manufacture reticulated metal foam via a dual investment solid mold includes pouring molten metal material into a mold while the mold is located on a chill plate. A method to manufacture reticulated metal foam includes pouring molten metal material into a mold while the mold is located on a chill plate, the chill plate configured to apply an externally driven temperature gradient in the mold so that solidification progresses from the chilled end to the non-chilled end

Expandable methyl methacrylate resin particles having a narrow particle size distribution, a good yield, and excellent expandability and formability are provided. The expandable methyl methacrylate resin particles include a base resin containing, as constitutional units, a certain amount of a methyl methacrylate unit and a certain amount of acrylic ester unit, and a blowing agent. The expandable methyl methacrylate resin particles have an average particle diameter of 0.6 mm to 1.0 mm and a particle diameter variation coefficient of not more than 20%.

Methods for forming metal articles are provided. The methods include forming foam casting molds from polylactic acid for use in lost foam and sand casting processes. The PLA-based foam casting molds advantageously reduce cycle time, reduce overall cost, increase reusability of the foam casting molds, reduce costs associated with shipping the foam casting mold, and improve yield and quality of cast metal articles.

A lost foam casting pattern that is constructed of a plastic filament, a foaming agent, and a coating. The lost foam casting pattern is printable on a 3-D printer. A 3-D printable material for the creation of a lost foam casting pattern is also disclosed where the material includes 95.0% to 99.75% by weight of a plastic filament combined with 0.25% to 5.00% by weight of a foaming agent. A method for preparing a lost foam casting pattern using the 3-D printable material is further described.