Methods and Systems for Welding Copper Using Blue Laser
A visible light laser system and operation for welding materials together. A blue laser system that forms essentially perfect welds for copper based materials. A blue laser system and operation for welding conductive elements, and in particular thin conductive elements, together for use in energy storage devices, such as battery packs.
1 - 83 . (canceled)
84 . A method of forming a weld in copper based materials, the method comprising:
a. placing a work piece in a laser system; wherein the work piece comprises placing a first piece of copper based material in contact with a second piece of copper material;
b. directing a laser beam at the work piece, whereby a weld is formed between the first piece of copper based material and the second piece of copper based material; wherein the weld comprises a HAZ and a resolidification zone; and,
c. wherein a microstructure of the copper based material, the HAZ and the resolidification zone show no discernable difference in the weld that would indicate a weakness in the weld, and/or wherein the identical microstructure comprises crystal growth regions of similar size.
85 . The method of claim 84 , wherein the laser beam is green.
86 . The method of claim 84 , wherein the weld is formed by conduction mode welding.
87 . The method of claim 84 , wherein the laser beam is directed to the work piece as a focused spot having power density
of less than 800 kW/cm 2 , or
of less than 500 kW/cm 2 , or
from about 100 kW/cm 2 to about 800 kW/cm 2 , or
from about 800 kW/cm 2 to about 5 MW/cm 2 , or
greater than 100 kW/cm 2 .
88 . The method of claim 84 , comprising applying a shielding gas selected from the group consisting of He, Ar, N 2 .
89 . The method of claim 84 , comprising applying a shielding gas and adding hydrogen to remove oxide layers and promote wetting of the weld.
90 . The method of claim 84 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
91 . The method of claim 89 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
92 . The method of claim 91 , wherein the laser beam is blue.
93 . A method of forming a weld in copper based materials, the method comprising:
a. placing a work piece in a laser system; wherein the work piece comprises placing a first piece of copper based material in contact with a second piece of copper material;
b. directing a laser beam at the work piece, whereby a weld is formed between the first piece of copper based material and the second piece of copper based material; wherein the weld comprises a HAZ and a resolidification zone; and,
wherein a range of hardness for the HAZ is within a range of hardness for the copper based material.
94 . The method of claim 93 , wherein the laser beam is green.
95 . The method of claim 93 , wherein the range of hardness for the resolidification zone is within a range of hardness for the copper based material.
96 . The method of claim 94 , wherein the range of hardness for the resolidification zone is within a range of hardness for the copper based material.
97 . The method of claim 93 , wherein a microstructure of the copper based material, the HAZ and the resolidification zone are identical.
98 . The method of claim 93 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
99 . The method of claim 94 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
100 . A method of forming a keyhole weld in copper based materials, the method comprising:
a. placing a work piece in a laser system; wherein the work piece comprises placing a first piece of copper based material in contact with a second piece of copper material; and,
b. directing a laser beam at the work piece, thereby forming a HAZ and a resolidification zone, whereby a keyhole mode weld is formed between the first piece of copper based material and the second piece of copper based material; wherein the weld comprises a HAZ and a resolidification zone; and,
c. wherein the blue laser beam is directed in a splatter reducing operation comprising one of more of: elongating the laser beam to suppress spatter from the keyhole; modulating the laser power to suppress spatter from the keyhole; rapidly scanning the beam to suppress spatter during the keyhole mode of welding; and, comprising rapidly decreasing the laser power after the weld is initiated.
101 . The method of claim 100 , wherein the laser beam is blue.
102 . The method of claim 100 , wherein the laser beam is green.
103 . The method of claim 100 , comprising applying a shielding gas selected from the group consisting of He, Ar, N 2 .
104 . The method of claim 100 , comprising applying a shielding gas and adding hydrogen to remove oxide layers and promote wetting of the weld.
105 . The method of claim 100 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
106 . The method of claim 101 , comprising directing a second laser beam to the same area as the laser beam to form the weld.
107 . The method of claim 102 , comprising directing a second laser beam to the same area as the laser beam to form the weld.