Provided herein are methods for making a freeze-cast material having a internal structure, the methods comprising steps of: determining the internal structure of the material, the internal structure having a plurality of pores, wherein: each of the plurality of pores has directionality; and the step of determining comprises: selecting a temperature gradient and a freezing front velocity to obtain the determined internal structure based on the selected temperature gradient and the selected freezing front velocity; directionally freezing a liquid formulation to form a frozen solid, the step of directionally freezing comprising: controlling the temperature gradient and the freezing front velocity to match the selected temperature gradient and the selected freezing front velocity during directionally freezing; wherein the liquid formulation comprises at least one solvent and at least one dispersed species; and subliming the at least one solvent out of the frozen solid to form the material.

A method for building an ice structure includes making a plurality of ice logs or ice beams and attaching the ice logs together to form a support structure. The support structure may be two or more stories high and may be constructed by freezing the ice logs or ice beams together.

Sintered product having a relative density of greater than 90%, with, to more than 80% of the volume thereof, a stack of flat ceramic platelets, the assembly of the platelets having a mean thickness of less than 3 m, having a width of greater than 50 mm, and including more than 20% of alumina, as a percentage on the basis of the weight of the product. The width of the product is the largest dimension measured in the plane in which the length of the product is measured, along a direction perpendicular to the direction of the length. The length of the product is the largest dimension thereof in a plane parallel to the general plane in which the platelets extend.

This invention provides a de-molding system of ceramic parts manufactured by freeze-casting comprising a mold (9), wherein the mold (9) comprises an upper opening (95) and a lower opening (94), wherein the upper opening (95) is adapted to receive a colloidal suspension (92), and one of the openings is adapted to allow the passage of a manufactured ceramic part (92), characterized by comprising at least one main de-molding element (80) adapted to actuate a ceramic part manufactured (92) through an opening in the mold (9).

In addition, the invention provides a mold cooling system for the manufacturing of ceramic parts by freeze-casting comprising: a source (1) of cooling gas; a cooling gas cooling medium (7) fluidically connected to the cooling gas source (1); and a cooling cell (5), fluidly connected to the cooling gas cooling medium (7), comprising a mold (9) in its interior, wherein the cooling cell (5) comprises a refrigerated cooling gas injection opening. Thus, a mold cooling system is provided for the manufacturing of ceramic parts by freeze-casting comprising the stages of: refrigerating a cooling gas coming from a cooling gas source (1); and injecting a cooling gas that is refrigerated in a cooling cell (5) comprising a mold (9) in its interior.

A freeze tape casting system is provided that maximizes the production speed of a tape material with a directional porosity through a thickness of the tape material. Embodiments of the system may have multiple freeze zones where a freeze zone has a temperature profile and dwell time that is tailored to one or more parts of the physical process of freezing a solvent in the tape material to create the directional porosity. Various zones can be directed to physical processes such as nucleation, transitional crystal growth, steady crystal growth, maintaining the tape material in a frozen state, sublimating the frozen solvent, etc. As a result, the physical processes are decoupled from each other to maximize production speed. The resulting material has applicability in electrodes, current collectors, and other products.

A metal object is created, layer by layer, by extruding a metallic water-based paste containing a low amount of binder, using a positive displacement pump located near the nozzle. A support structure is created by a second pump using a low strength water-based paste. The object is partially dried as it is printed, followed by full drying and sintering.

This disclosure provides systems, methods, and apparatus related to freeze casting. In one aspect, a method comprises providing an apparatus. The apparatus comprises a container and a cooling surface. A bottom of the container comprises a wedge. The wedge comprises a first substantially planar surface and a second substantially planar surface with an angle between the first and the second substantially planar surfaces. An interior bottom of the container comprises the second substantially planar surface. The cooling surface is in contact with the first substantially planar surface. A slurry is deposited on the second substantially planar surface, the slurry comprising a plurality of particles in a liquid. The cooling surface is cooled to cool the slurry at a specified cooling rate.

A 3D printer creates a ceramic casting shell of high accuracy. Casting molten metal into this shell creates an accurate metal object. The ceramic shell is formed from a paste made from a low hardness ceramic, dried by freeze drying. To overcome the shear thinning behaviour of ceramic pastes a positive displacement pump is in close proximity to the nozzle.

A method of manufacturing a porous part includes controlled freeze casting of a slurry. After freezing, a solvent in the slurry is removed by sublimation and the remaining material is sintered to form the porous part. Spatial and temporal control of thermal conditions at the boundary and inside of the mold can be controlled to create parts with controlled porosity, including size, distribution, and directionality of the pores. Porous parts with near-net-shape from ceramics, metals, polymers and other materials and their combinations can be created.

A method of making a refractory article is provided. The method includes: a) mixing a binder system, a refractory charge, and a second colloidal binder to form an aqueous slurry; b) casting the aqueous slurry into a mold; c) subjecting the mold containing the aqueous slurry to a temperature that is lower than a slurry casting temperature for a time sufficient to form a green strength article; and d) firing the green strength article at a temperature of at least 450? C. for a time sufficient to achieve thermal homogeneity, thereby forming a refractory article. Refractory articles made in accordance with the method have a unique combination of pore structure and mechanical properties.