APPENDIX H: DEFINING THE OPTIMUM PROCESS
2 KHZ INVERTER WEDLING POWER SUPPLY
990-057
H-3
Consider the Material Properties
The important material properties to be considered in the resistance welding process are:
•
Electrical and thermal conductivity
•
Plating and coating
•
Hardness
•
Melting point
•
Oxides
The figure below illustrates the variance in resistivity and melting points for some of the more common
materials used in micro resistance welding today.
The materials can be grouped into three common categories. The types of joints achievable within each
of the main groups are detailed below:
•
Group I – Conductive Metals
Conductive metals dissipate heat and it can be difficult to focus heat at the interface. A solid-
state joint is therefore preferred. Typically, resistive electrode materials are used to provide
additional heating.
500
1000
1500
2000
2500
3000
3500
200
400
600
800
Al
Cu
Ni
Mo
Nb
Pt
Ag
Ta
Ti
W
Inconel
Ti-6Al-4V
Pt-Ir
Nichrome
Bro
Br
G
Steel
Resistivity
(nano-ohm)
Melting Point (
°
C)
Stainless Steels
(304, 316, etc.)
Group I
OFF Scale
Group II
Group III
