Variation of laser energy transfer efficiency with well pool depth
A series of CO{sub 2} laser welds were made at a constant beam irradiance of 6 MW/cm{sup 2} on 304 stainless steel with travel speeds selected to produce welds with varying levels of weld penetration. Using a Seebeck envelope calorimeter, the net heat input to the part was measured for each weld. It was found that the energy transfer efficiencies varied from 0.29 to 0.86, and decreased at high travel speeds where the weld penetration depth was as shallow as 0.13 mm. The decrease in beam absorption with decreasing weld pool depth is consistent with an absorption mechanism that requires multiple internal reflections within the weld pool. Equations have been developed which conn -ct the keyhole cavity dimensions with the energy transfer efficiency, and correlations with the experimental data have determined the keyhole cavity radius to be 0.1 mm for a focused laser beam with a spot radius of 0.059 mm.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 168693
- Report Number(s):
- SAND-95-2493C; CONF-9511146-1; ON: DE96002475
- Resource Relation:
- Conference: 14. international congress on applications of lasers and electro-optics, San Diego, CA (United States), 13-16 Nov 1995; Other Information: PBD: [1995]
- Country of Publication:
- United States
- Language:
- English
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