Localized multiple beamed laser peening of connecting rod
AssigneeGM Global Technology Operations LLC
InventorsJianghuai Yang, Ronald J. Helmstadt, Qigui Wang, Richard D. Ricchi
Life of this patent
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Abstract
A connecting rod for a vehicle and a method of laser peening a connecting rod. The connecting rod defines a pin opening at a first end and a cylindrical bore at a second end. A clear coating is applied on a first target surface and a second target surface of the connecting rod. The first and second opposing target surfaces are impinged in a localized area between the pin opening and the cylindrical bore with a plurality of pulses of pulsed laser beams. After laser peening, the localized area between the pin opening and the cylindrical bore exhibits compressive residual stresses at a depth of up to 0.75 millimeters.
Claims20
A method of laser peening a connecting rod for a vehicle, comprising:
- applying a clear coating on a first target surface and a second target surface of a connecting rod, wherein the connecting rod defines a pin opening at a first end and a cylindrical bore at a second end;
- impinging the first target surface in a localized area between the pin opening and the cylindrical bore with a first plurality of pulses of a first pulsed laser beam;
- impinging the second target surface in the localized area with a second plurality of pulses of a second pulsed laser beam, wherein the second target surface opposes the first target surface and the first plurality of pulses and the second plurality of pulses are emitted at the same time;
- and
- forming a compressive residual stress to the first target surface and the second target surface at a depth of up to 0.75 millimeters.
A method of cold working a connecting rod for a vehicle, comprising emitting from at least one laser source a first plurality of pulses of a first pulsed laser beam and a second plurality of pulses of a second pulsed laser beam;
- impinging a first target surface in a localized area of a connecting rod including a clear coating with the first plurality of pulses, wherein the connecting rod defines a pin opening at a first end and a cylindrical bore at a second end and the localized area is between the pin opening and the cylindrical bore;
- impinging a second target surface of the connecting rod including the clear coating with the second plurality of pulses, wherein the second target surface opposes the first target surface and the pulses of the first pulsed laser beam and the second pulsed laser beam are emitted at the same time;
- evaporating a portion of the first target surface and generating a first plasma and evaporating a portion of the second target surface and generating a second plasma;
- trapping the first plasma between the clear coating and the first target surface and trapping the second plasma between the clear coating and the second target surface;
- expanding the first plasma and creating a first shockwave and expanding the second plasma and the second shockwave;
- and
- forming a first compressive residual stress at the first target surface in the range of 500 Megapascals (MPa) to 1000 MPa, and a second compressive residual stress at the second target surface in the range of 500 Megapascals (MPa) to 1000 MPa, wherein the first and second compressive residual stresses are at a depth of up to 0.75 millimeters.
A connecting rod for a vehicle, comprising:
- a connecting rod defining a pin opening at a first end and a cylindrical bore at a second end;
- and
- an overlay present on a surface of the connecting rod;
- and
- a localized area between the pin opening and the cylindrical bore, wherein a portion of the overlay is removed in the localized area and wherein the localized area exhibits compressive residual stresses in the range of 500 Megapascals (MPa) to 1000 MPa at a depth of up to 0.75 millimeters.
Dependencies are inferred from the claim text.