APPENDIX F: DEFINING THE OPTIMUM PROCESS
CD-A DUAL PULSE RESISTANCE WELDING POWER SUPPLY
F-8
990-430
Approach to Weld Development
The first stage in developing a quality welding process is to fix as many of the variables as possible in the
welding equipment set up. The welding variables can be grouped in the following categories:
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Material Variables
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Base material
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Plating
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Size
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Shape
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Weld Head & Mechanical Variables
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Force, squeeze, hold
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Actuation method
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Electrode material and shape
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Power Supply Variables
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Energy
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Time (squeeze, weld, hold)
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Process Variables
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Tooling, level of automation
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Repetition rate
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Part positioning
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Maintenance, electrode cleaning
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Quality Requirements
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Pull strength
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Visual criteria
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Test method, other weld joint requirements
The first stage in developing a quality welding process is to fix as many of the variables as possible in the
welding equipment set up. Welding variables can be grouped in the following categories:
Initial Welding Trials -- The “Look See” Tests
“Look see” welding tests are a series of mini welding experiments designed to provide a starting point for
further statistical development of the welding parameters. The user should adjust the key welding
variables (energy, force, time) in order to identify the likely good “weld window.” Close visual inspection
of the weld parts will promote better understanding of the heating characteristics of the application.
The mini-experiments should also be used to understand the weld characteristics from both application
and process perspective. Key factors in this understanding are as follows:
Application Perspective
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Materials: Resistivity, melting point, thermal mass, shape, hardness, surface properties.
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Heat balance: Electrode materials, shape, Polarity, heating rate (upslope).
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Observation: visual criteria, cross section, and impact of variables on heat balance.
