APPARATUS AND METHODS FOR JOINING DISSIMILAR MATERIALS
An apparatus is provided including: at least one first sheet comprising a first material; at least one second sheet comprising a second material, wherein the first material comprises at least one of: a thermal conductivity and an electrical conductivity that is at least 10% lower than that of the second material; and a joint comprising at least one resistance spot weld (RSW), wherein the first sheet is at least about 1.5 times the thickness of the second sheet. Methods are also provided.
1 - 17 . (canceled)
18 . A method, comprising:
overlapping at least one first sheet of a first material with at least one second sheet of a second material, wherein the first material is different than the second material, further wherein the first sheet comprises a thickness ratio of at least 1.5 the thickness of the second sheet;
contacting a pair of electrodes to opposing faces of the first sheet and second sheet to define a weld zone,
wherein at least one of the electrodes comprises an electrode insert having an electrical conductivity of not greater than about 54% IACS;
welding the first sheet to the second sheet across the weld zone to provide at least one resistance spot weld to join the first sheet to the second sheet.
19 . The method of claim 18 , wherein the contacting step further comprises:
applying a force to the first sheet and second sheet across the weld zone of at least about 2 kN prior to welding.
20 . The method of claim 18 , wherein the welding step further comprises:
applying a current of not greater than about 45 kA to the weld zone for a weld time of not greater than about 500 milliseconds.