Cellular materials formed using surface transformation

A method of forming cellular material to have a predictable mechanical fatigue site for a given force, comprising:

• forming a predetermined arrangement of a plurality of holes in a volume of material through a surface of the volume of material;
• and
• annealing the volume of material such that the volume of material undergoes a surface transformation to transform the arrangement of the plurality of holes into a predetermined arrangement of at least one empty space below the surface of the volume of material,
• wherein forming a predetermined arrangement of a plurality of holes includes forming a predetermined arrangement of a plurality of holes adapted to form a predetermined pattern of at least one empty void suitably positioned to provide the volume of material with a predictable fatigue site for a given force.

A method of forming cellular material to have a number of empty spaces that provide an approximately uniform density and a majority of the number of empty spaces being closed, comprising:

• forming a predetermined arrangement of a plurality of holes in a volume of material through a surface of the volume of material;
• and
• annealing the volume of material such that the volume of material undergoes a surface transformation to transform the arrangement of the plurality of holes into a predetermined arrangement of at least one empty space below the surface of the volume of material,
• wherein a relationship between stiffness (S) and density (ρ) for the cellular material approaches S∝ρ−2.

A method of forming cellular material, comprising:

• forming a first predetermined arrangement of a plurality of first holes in a volume of material through a first surface of the volume of material, each of the first holes having a predetermined length and diameter;
• annealing the volume of material such that the volume of material undergoes a surface transformation to transform the first arrangement of the first holes into a first arrangement of at least one empty space in the volume of material;
• forming a second predetermined arrangement of a plurality of second holes in the volume of material through a second surface of the volume of material, each of the second holes having a predetermined length and diameter;
• and
• annealing the volume of material such that the volume of material undergoes a surface transformation to transform the second arrangement of the second holes into a second arrangement of at least one empty space in the volume of material.

A method of forming cellular material, comprising:

• depositing a first layer of material;
• forming a first arrangement of holes through a surface of the first layer of material;
• annealing the first layer of material such that the first layer of material undergoes a surface transformation to transform the first arrangement of holes into a first arrangement of at least one empty space below the surface of the first layer of material;
• depositing a second layer of material on the first layer of material;
• forming a second arrangement of holes through a surface of the second layer of material;
• and
• annealing the second layer of material such that the second layer of material undergoes a surface transformation to transform the first arrangement of holes into a second arrangement of at least one empty space below the surface of the first layer of material.

A structure of cellular material, comprising:

• a solid structure of material having a well-defined melting temperature and a well-defined annealing temperature below the melting temperature suitable to perform a surface transformation process;
• and
• a precisely-determined arrangement of a plurality of voids formed within the solid structure, the plurality of voids being separated by a critical length (λC) that is dependent on the radius (RC) of a number of holes used to form the plurality of voids using the surface transformation process,
• wherein a majority of the precisely-determined arrangement of the plurality of voids within the solid structure are closed and approximately uniformly spaced to provide the structure of cellular material with a uniform density.

A structure of cellular material, comprising:

• a solid structure of material having a well-defined melting temperature and a well-defined annealing temperature below the melting temperature suitable to perform a surface transformation process;
• and
• a precisely-determined arrangement of a plurality of voids formed within the solid structure, the plurality of voids being separated by a critical length (λC) that is dependent on the radius (RC) of a number of holes used to form the plurality of voids using the surface transformation process,
• wherein the precisely-determined arrangement of the plurality of voids within the solid structure are arranged to provide the structure with a predictable mechanical failure for a given force.