A manufacturing method of the honeycomb structure uses a grinding wheel having a coarse abrasive grain layer and a pair of fine abrasive grain layers sintered and secured to be formed on both sides of the coarse abrasive grain layer, and has a grinding wheel rotating step of rotating the pair of grinding wheels disposed via a predetermined space in a state where fine abrasive grain layers of the grinding wheels face each other; a conveying step of conveying a honeycomb formed body formed by extrusion and the like; an end face grinding step of grinding end faces of the conveyed honeycomb formed body with the rotating grinding wheels; and a firing step of firing the honeycomb formed body.

A manufacturing method of the honeycomb structure uses a grinding wheel having a coarse abrasive grain layer and a pair of fine abrasive grain layers sintered and secured to be formed on both sides of the coarse abrasive grain layer, and has a grinding wheel rotating step of rotating the pair of grinding wheels disposed via a predetermined space in a state where fine abrasive grain layers of the grinding wheels face each other; a conveying step of conveying a honeycomb formed body formed by extrusion and the like; an end face grinding step of grinding end faces of the conveyed honeycomb formed body with the rotating grinding wheels; and a firing step of firing the honeycomb formed body.

The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows:
1.5T16(100P).sup.1.4; andEquation (1):
20P75Equation (2).

The honeycomb structure includes a pillar-shaped honeycomb structure body, and a circumferential coating layer disposed to surround a circumference of the honeycomb structure body, and cells which are formed at an outermost circumference of the honeycomb structure body and in which peripheries of the cells are defined by the partition walls without any lacks are defined as outermost circumference complete cells, and in a cross section of the honeycomb structure body which is perpendicular to an extending direction of the cells a minimum distance T (mm) among distances from the outermost circumference complete cells to the surface of the circumferential coating layer and a porosity P (%) of the circumferential coating layer satisfy relations of Equation (1) and Equation (2) as follows:
1.5T16(100P).sup.1.4; andEquation (1):
20P75Equation (2).

A medical use honeycomb structure having a plurality of through-holes extending in one direction, wherein an outer peripheral section of the medical use honeycomb structure has a through-hole groove formed by incomplete side walls of the through-hole, and a through-hole inlet adjacent to the through-hole groove.

A lightweight thermal insulating cement-based material is formed from a mixture that includes cement, water and a foaming agent. The foaming agent can be an aluminum powder or a surfactant. The insulating material has a maximum use temperature of about 900 degrees Celsius or more.

A lightweight thermal insulating cement-based material is formed from a mixture that includes cement, water and a foaming agent. The foaming agent can be an aluminum powder or a surfactant. The insulating material has a maximum use temperature of about 900 degrees Celsius or more.

An airfoil for a gas turbine engine is provided that includes a first portion formed from a first plurality of plies of a ceramic matrix composite material and defining an inner surface of the airfoil, as well as a second portion formed from a second plurality of plies of a ceramic matrix composite material and defining an outer surface of the airfoil. The first portion and the second portion define a non-line of sight cooling aperture extending from the inner surface to the outer surface of the airfoil. In one embodiment, a surface angle that is less than 45 is defined between a second aperture and the outer surface. A method for forming an airfoil for a gas turbine engine also is provided.

An airfoil for a gas turbine engine is provided that includes a first portion formed from a first plurality of plies of a ceramic matrix composite material and defining an inner surface of the airfoil, as well as a second portion formed from a second plurality of plies of a ceramic matrix composite material and defining an outer surface of the airfoil. The first portion and the second portion define a non-line of sight cooling aperture extending from the inner surface to the outer surface of the airfoil. In one embodiment, a surface angle that is less than 45 is defined between a second aperture and the outer surface. A method for forming an airfoil for a gas turbine engine also is provided.

A lightweight thermal insulating cement-based material is formed from a mixture that includes cement, water and a foaming agent. The foaming agent can be an aluminum powder or a surfactant. The insulating material has a maximum use temperature of about 900 degrees Celsius or more.