Any one or more members of an engine, that is, a piston, a cylinder head and a valve, has a wall face disposed face-to-face to a combustion chamber, and the wall face is coated by a heat-insulation coating film. The heat-insulation coating film includes a heat-insulative layer formed on a surface of the wall face, and an inorganic-system coated-film layer formed on a surface of the heat-insulative layer. The heat-insulative layer includes a resin, and first hollow particles buried inside the resin and exhibiting an average particle diameter being smaller than a thickness of the heat-insulative layer. The inorganic-system coated-film layer includes an inorganic compound.

Any one or more members of an engine, that is, a piston, a cylinder head and a valve, has a wall face disposed face-to-face to a combustion chamber, and the wall face is coated by a heat-insulation coating film. The heat-insulation coating film includes a heat-insulative layer formed on a surface of the wall face, and an inorganic-system coated-film layer formed on a surface of the heat-insulative layer. The heat-insulative layer includes a resin, and first hollow particles buried inside the resin and exhibiting an average particle diameter being smaller than a thickness of the heat-insulative layer. The inorganic-system coated-film layer includes an inorganic compound.

Making a piston includes receiving a piston crown including a combustion face forming a combustion bowl. The piston includes a base material, and a thermal barrier coating (TBC) material forming at least a portion of the combustion face including a bowl edge. Making a piston further includes advancing a polishing tool into contact with the combustion face, spinning the polishing tool such that a positive piston profile is polished via contact with a negative tool profile, and removing some of the TBC material based on the spinning the polishing tool relative to the piston.

Provided are a heat-resistant member provided with a heat-shielding coating suitable for stable manufacturing and excellent in heat-insulating, thermoresponsive and distortion accommodating properties, and a method for manufacturing the same. The heat-shielding coating includes a metallic portion formed of agglomerates of a plurality of metal particles, and inorganic compound particles dispersed in the metallic portion. The metal particles are diffusion-bonded each other, and the metallic portion and a base material of the heat-resistant member are diffusion-bonded each other. The manufacturing method includes the steps of depositing mixed particles of the metal particles and the inorganic compound particles on a surface of the base material in a film shape; resistance-heating the mixed particles by current-passing while pressurized in a thickness direction; diffusion-bonding the metal particles each other; and the metallic portion and the base material each other.

A piston for an internal combustion engine and method of construction thereof are provided. The piston includes an upper crown formed at least in part by a first metal material and a thermally insulating insert. The upper crown has an upper wall forming an upper combustion surface and a ring belt region. The upper combustion surface is formed at least in part by the thermally insulating insert. The thermally insulating insert has a base surface with pores extending upwardly therein. The first metal material is infused and solidified in the pores, with the first metal material forming a first bonding surface. The piston further includes a body portion formed from a second metal material. The body portion provides pin bosses having coaxially aligned pin bores and diametrically opposite skirt portions. The body portion has a second bonding surface bonded to the first bonding surface of the first metal material.

A piston for an internal combustion engine and method of construction thereof are provided. The piston includes an upper crown formed at least in part by a first metal material and a thermally insulating insert. The upper crown has an upper wall forming an upper combustion surface and a ring belt region. The upper combustion surface is formed at least in part by the thermally insulating insert. The thermally insulating insert has a base surface with pores extending upwardly therein. The first metal material is infused and solidified in the pores, with the first metal material forming a first bonding surface. The piston further includes a body portion formed from a second metal material. The body portion provides pin bosses having coaxially aligned pin bores and diametrically opposite skirt portions. The body portion has a second bonding surface bonded to the first bonding surface of the first metal material.

A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.

A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.

A thermal barrier coating for an internal combustion engine includes an insulating thermal spray coating, where a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form and the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed.

An object of the present invention is to enhance the thermal efficiency of an engine, to provide a film having low thermal conductivity and low heat capacity and being free from separation, drop-off and the like and excellent in durability and reliability. According to the present invention, an engine combustion chamber structure, wherein an anodic oxide film having a thickness of from more than 20 μm to 500 μm and a porosity of 20% or more is formed on the inner surface of the engine combustion chamber, and a manufacturing method thereof are provided.