US 12,290,871 B2
Method and system for joining workpieces
Steven Cipriano, Chesterfield Township, MI (US); Pei-chung Wang, Forest Hills, NY (US); Zhenke Teng, Troy, MI (US); and Anthony V. Minatel, Fenton, MI (US)
Assigned to GM Global Technology Operations LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Nov. 16, 2022, as Appl. No. 17/987,913.
Prior Publication US 2024/0157463 A1, May 16, 2024
Int. Cl. B23K 11/20 (2006.01); B23K 11/11 (2006.01); B23K 35/36 (2006.01); B23K 37/00 (2025.01); B23K 103/04 (2006.01); B23K 103/10 (2006.01)
CPC B23K 11/20 (2013.01) [B23K 11/115 (2013.01); B23K 35/3613 (2013.01); B23K 37/00 (2013.01); B23K 2103/04 (2018.08); B23K 2103/10 (2018.08)] 5 Claims
OG exemplary drawing
 
1. A method for joining multiple workpieces, the method comprising:
dispensing adhesive on a first workpiece in an uncured condition in which the adhesive has a cure content of from 0% to 15%;
contacting a second workpiece with the adhesive such that the adhesive is disposed between the first and second workpieces;
contacting the first workpiece with a first electrode;
contacting the second workpiece with a second electrode;
after contacting the first workpiece with the first electrode and contacting the second workpiece with the second electrode, producing resistance heating in the first and second workpieces at first processing conditions to form a partially cured adhesive having a cure content of from 20% to 75% and affix the first and second workpieces together to form a partially cured, adhesive-joined workpiece assembly;
wherein producing resistance heating includes producing an electrical current between the first and second electrodes of from 1.5 kA to 2.5 kA for 1.5 seconds to 2.5 seconds to produce a temperature in the first and second workpieces of from 200° C. to 375° C.;
wherein producing resistance heating includes the first and second electrodes applying a force of from 3 kN to 5 kN to the first and second workpieces to squeeze the adhesive between the first and second workpieces to a thickness of from 100 μm to 4000 μm; and
exposing the partially cured, adhesive-joined workpiece assembly to heat at second processing conditions that include a temperature of from 150° C. to 200° C. for a time of from 15 minutes to 25 minutes to form a substantially fully cured adhesive;
wherein the substantially fully cured adhesive has a cure content of from 85% to 100%.