| Autor: |
Chad M. Ellison, Jerome T. Norris, Matthew Joseph. Perricone, Kevin M. Faraone |
| Rok vydání: |
2007 |
| Předmět: |
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| DOI: |
10.2172/921738 |
| Popis: |
Weld porosity is being investigated for long-pulse spot welds produced by high power continuous output lasers. Short-pulse spot welds (made with a pulsed laser system) are also being studied but to a much small extent. Given that weld area of a spot weld is commensurate with weld strength, the loss of weld area due to an undefined or unexpected pore results in undefined or unexpected loss in strength. For this reason, a better understanding of spot weld porosity is sought. Long-pulse spot welds are defined and limited by the slow shutter speed of most high output power continuous lasers. Continuous lasers typically ramp up to a simmer power before reaching the high power needed to produce the desired weld. A post-pulse ramp down time is usually present as well. The result is a pulse length tenths of a second long as oppose to the typical millisecond regime of the short-pulse pulsed laser. This study will employ a Lumonics JK802 Nd:YAG laser with Super Modulation pulse shaping capability and a Lasag SLS C16 40 W pulsed Nd:YAG laser. Pulse shaping will include square wave modulation of various peak powers for long-pulse welds and square (or top hat) and constant ramp downmore » pulses for short-pulse welds. Characterization of weld porosity will be performed for both pulse welding methods.« less |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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