Laser spot welding of overlapping aluminum workpieces
AssigneeGM Global Technology Operations LLC
InventorsDavid Yang, Wu Tao
Life of this patent
Estimating the term…
Abstract
A method of laser welding a workpiece stack-up (10) that includes at least two overlapping aluminum workpieces comprises advancing a laser beam (24) relative to a plane of a top surface (20) of the workpiece stack-up (10) and along a beam travel pattern (74) that lies within an annular weld area (82) defined by an inner diameter boundary (86) and an outer diameter boundary (84) on the plane of the top surface (20). The beam travel pattern (74) of the laser beam (24) surrounds a center area encircled by the annular weld area (82) on the plane of the top surface (20) so as to force entrained porosity inwards into a region of the weld joint (72) beneath the center area on the plane of the top surface (20) of the workpiece stack-up (10).
Claims19
A method of laser welding a workpiece stack-up that includes at least two overlapping aluminum workpieces, the method comprising:
- providing a workpiece stack-up that includes overlapping aluminum workpieces, the workpiece stack-up comprising at least a first aluminum workpiece and a second aluminum workpiece, the first aluminum workpiece providing a top surface of the workpiece stack-up and the second aluminum workpiece providing a bottom surface of the workpiece stack-up, wherein a faying interface is established between each pair of adjacent overlapping aluminum workpieces within the workpiece stack-up, and wherein at least one of the aluminum workpieces in the workpiece stack-up includes a protective surface coating;
- directing a laser beam at the top surface of the workpiece stack-up to create a molten aluminum weld pool that penetrates into the workpiece stack-up from the top surface towards the bottom surface and intersects each faying interface established within the workpiece stack-up;
- and
- forming a laser weld joint by advancing the laser beam relative to a plane of the top surface of the workpiece stack-up along a beam travel pattern that lies within an annular weld area defined by an inner diameter boundary and an outer diameter boundary on the plane of the top surface, the beam travel pattern of the laser beam surrounding a center area encircled by the annular weld area on the plane of the top surface so as to force entrained porosity inwards into a region of the weld joint beneath the center area on the plane of the top surface of the workpiece stack-up.
A method of remote laser welding a workpiece stack-up that includes at least two overlapping aluminum workpieces, the method comprising:
- providing a workpiece stack-up that includes overlapping aluminum workpieces, the workpiece stack-up comprising at least a first aluminum workpiece and a second aluminum workpiece, the first aluminum workpiece providing a top surface of the workpiece stack-up and the second aluminum workpiece providing a bottom surface of the workpiece stack-up, wherein a faying interface is established between each pair of adjacent overlapping aluminum workpieces within the workpiece stack-up, and wherein at least one of the aluminum workpieces in the workpiece stack-up includes a protective surface coating;
- operating a scanning optic laser head to direct a solid-state laser beam at the top surface of the workpiece stack-up to create a molten aluminum weld pool that penetrates into the workpiece stack-up from the top surface towards the bottom surface, the solid-state laser beam having a focal length between 0.4 meters and 2.0 meters;
- and
- coordinating the movement of tiltable scanning mirrors within the scanning optic laser head to advance the laser beam relative to a plane of the top surface of the workpiece stack-up along a beam travel pattern that lies within an annular weld area defined by an inner diameter boundary and an outer diameter boundary on the plane of the top surface, the beam travel pattern of the laser beam surrounding a center area encircled by the annular weld area on the plane of the top surface so as to force entrained porosity inwards into a region of a resultant weld joint beneath the center area, and wherein the laser beam is advanced along the beam travel pattern at a travel speed that ranges from 8 m/min to 120 m/min.
Dependencies are inferred from the claim text.