Laser hardened pattern array in cylinder bores

A vehicle, comprising:

• an internal combustion engine, including an engine block and a piston;
• a bore surface defined in the internal combustion engine, wherein the bore surface defines a cylinder bore and the bore surface exhibits a first microstructure, and wherein the bore surface includes an upper portion and a lower portion;
• a piston ring mounted on the piston, wherein the piston ring reciprocally contacts at least a portion of the upper portion of the bore surface;
• and
• a pattern of a plurality of cycloidal features formed in the bore surface,
• wherein the plurality of cycloidal features each exhibit a first length in a first axis and a second length in a second axis arranged 90 degrees from the first axis,
• wherein the plurality of cycloidal features exhibit a ratio of the first length to the second length in a range of 1:1.5 to 1.5:1,
• wherein the plurality of cycloidal features extend a depth into the bore surface in the range of 500 micrometers to 1 millimeters in depth,
• wherein the plurality of cycloidal features exhibits a second microstructure including tempered martensite, and
• wherein the second microstructure are different from the first microstructure.

A method of forming a patterned array on a cylinder bore surface, comprising:

• impinging a bore surface with a laser, wherein the bore surface defines a cylinder bore and the bore surface exhibits a first microstructure;
• forming with the laser a pattern of a plurality of cycloidal features formed in the bore surface, wherein the plurality of cycloidal features each exhibit a first length in a first axis and a second length in a second axis positioned 90 degrees from the first axis, wherein the plurality of cycloidal features extend a depth into the bore surface in the range of 500 micrometers to 1 millimeters in depth, wherein the plurality of cycloidal features exhibit a second microstructure different from the first microstructure, wherein the second microstructure includes martensite, and wherein the plurality of cycloidal features exhibit a ratio of the first length to the second length in a range of 1:1.5 to 1.5:1;
• and
• tempering the plurality of cycloidal features with the laser.