US 12,330,258 B2
Methods of ultrasonic drilling for forming perforations in composite materials
Weidong Song, Woodinville, WA (US)
Assigned to The Boeing Company, Arlington, VA (US)
Filed by The Boeing Company, Chicago, IL (US)
Filed on Feb. 20, 2020, as Appl. No. 16/796,606.
Prior Publication US 2021/0260712 A1, Aug. 26, 2021
Int. Cl. B24B 1/04 (2006.01); B26D 7/08 (2006.01)
CPC B24B 1/04 (2013.01) [B26D 7/086 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method of performing ultrasonic drilling to form a plurality of holes in a workpiece at a first location of the workpiece, the method comprising:
positioning a surface of the workpiece with respect to a tool of an ultrasonic hone, wherein the tool has a longitudinal axis that is substantially orthogonal to the surface of the workpiece, wherein the tool comprises a needle array comprising a plurality of needles, wherein each needle of the plurality of needles is oriented to extend along the longitudinal axis, wherein each respective needle of the plurality of needles is configured to form a respective hole of the plurality of holes in the workpiece when the tool is vibrated along the longitudinal axis, such that the plurality of holes are formed within a region of the workpiece without translating the tool with respect to the workpiece and without translating the workpiece with respect to the tool, wherein the plurality of needles are arranged in a distribution selected from the group consisting of a bilinear distribution and a pyramid distribution, wherein in the bilinear distribution, the plurality of needles are arranged according to their lengths such that a second end of each needle of the plurality of needles collectively form an angled contact plane for contacting the workpiece, and wherein in the pyramid distribution, the plurality of needles are arranged such that the second end of each needle of the plurality of needles collectively form a pyramidal contact shape for contacting the workpiece;
forming the plurality of holes in the workpiece by vibrating the tool along the longitudinal axis such that the tool repeatedly contacts the surface of the workpiece at an operating frequency and amplitude sufficient to form the plurality of holes in the workpiece, wherein the vibrating the tool is performed for a time sufficient to form the plurality of holes in the workpiece, wherein the tool is not rotated with respect to the surface of the workpiece during the forming the plurality of holes, wherein the forming the plurality of holes is performed without use of a slurry or a cooling fluid, and wherein the workpiece is composed of a composite material; and
locally heating a portion of the workpiece via a heating unit, wherein the first location is within the portion of the workpiece during the forming the plurality of holes in the workpiece.