An object of the present invention is to, while forming a heat insulating layer on a squish area surface of a top surface of a piston main body, prevent generation of large cracks on the heat insulating layer and suppress damages and peeling of the heat insulating layer. To achieve this object, in the present invention, a heat insulating layer on a squish area surface of a top surface of a piston main body is made thinner than a heat insulating layer on a cavity surface of the top surface of the piston main body.

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.

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.

In a method for producing a piston, a flat end surface 44a of a rotary tool 44 of a frictional pore sealing device is brought into abutment with the top surface 5a of a low thermal conductivity member 5 cast on the crown surface 2a of an aluminum alloy piston 1, and this rotary tool is pressed against the low thermal conductivity member's side with a load while rotating the rotary tool through an electric motor and a speed reduction mechanism. With this, a frictional heat between the top surface of the low thermal conductivity member and the end surface of the rotary tool causes to form a plastic flow layer 5d on the top surface, thereby sealing an opening portion of a pore 9a on the top surface of the porous member 6.

In a method for producing a piston, a flat end surface 44a of a rotary tool 44 of a frictional pore sealing device is brought into abutment with the top surface 5a of a low thermal conductivity member 5 cast on the crown surface 2a of an aluminum alloy piston 1, and this rotary tool is pressed against the low thermal conductivity member's side with a load while rotating the rotary tool through an electric motor and a speed reduction mechanism. With this, a frictional heat between the top surface of the low thermal conductivity member and the end surface of the rotary tool causes to form a plastic flow layer 5d on the top surface, thereby sealing an opening portion of a pore 9a on the top surface of the porous member 6.

A galleryless steel piston designed to improve thermal efficiency, fuel consumption, and performance of an engine is provided. The piston includes a steel body portion and a thermal barrier layer applied to an upper combustion surface and/or a ring belt to reduce the amount of heat transferred from a combustion chamber to the body portion. The thermal barrier layer has a thermal conductivity which is lower than a thermal conductivity of the steel body portion. The thermal barrier layer typically includes a ceramic material, for example ceria, ceria stabilized zirconia, and/or a mixture of ceria stabilized zirconia and yttria stabilized zirconia in an amount of 90 to 100 wt. %, based on the total weight of the ceramic material. The thermal barrier layer can also have a gradient structure which gradually transitions from 100 wt. % of a metal bond material to 100 wt. % of the ceramic material.

A coating for components of internal combustion engines, in particular for cylinder and/or piston surfaces that includes chromium with a mass fraction between 1 and 30%, iron with a mass fraction between 0 and 50%, carbides and/or oxides with a mass fraction between 0 and 50%, and a solid lubricant with a mass fraction between 0 and 30%.

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.

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.