Author Affiliations
1School of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou, Zhejiang 325035, China2Key Laboratory of Laser Processing Robot of Zhejiang Province, Wenzhou, Zhejiang 325035, China3Zhejiang Great Wall Commutator Co., Ltd., Wenzhou, Zhejiang 325200, Chinashow less
Fig. 1. Ultrafast laser precision micromachining system and microtexture preparation principle
Fig. 2. Schematic of pulse green laser welding device and overlap welding
Fig. 3. Copper/steel welded joint hardness measurement chart and tensile specimen. (a) Microhardness measurement diagram; (b) tensile specimen
Fig. 4. Morphologies of stainless steel surface before and after texturization. (a) Initial surface state; (b) surface state after laser etching
Fig. 5. Surface roughness of stainless steel before and after surface texturization
Fig. 6. Groove depth, width and depth-to-width ratio at different laser power
Fig. 7. Surface morphology, cross-sectional shape and geometric size of microtexture at different laser power. (a1)-(a5) Surface morphology; (b1)-(b5) cross-sectional shape; (c1)-(c2) geometric size
Fig. 8. Texture depth, width and depth-to-width ratio at different etching times
Fig. 9. Surface morphology, cross-sectional shape and geometric size of microtexture at different scanning times. (a1)-(a5) Surface morphology; (b1)-(b5) cross-sectional shape; (c1)-(c2) geometric size
Fig. 10. Microstructures of copper/surface untextured 304L stainless steel laser overlap welded joint. (a) Whole view; (b) enlarged view of region A; (c) enlarged view of region B; (d) enlarged view of region C
Fig. 11. Microstructures of copper/surface textured 304L stainless steel laser overlap welded joint. (a) Whole view; (b) enlarged view of region A; (c) enlarged view of region B; (d) enlarged view of region C
Fig. 12. EDS line scanning of the bottom part of molten pool of copper/surface untextured 304L stainless steel laser overlap welded joint. (a) Line scanning position; (b) EDS result
Fig. 13. EDS line scanning of the bottom part of molten pool of copper/surface textured 304L stainless steel laser overlap welded joint. (a) Line scanning position; (b) EDS result
Fig. 14. Microhardness distribution curves of welded joints
Fig. 15. Relationship between tensile strength and groove depth of copper/steel overlap welded joint
Fig. 16. Tensile fracture morphology of copper/steel laser overlap welded joints. (a) Untextured joint; (b) textured joint (groove depth:89.91 μm)
Material | Mass fraction /% |
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Cu | Bi | Sb | As | Fe | Sn | S |
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T2 | 99.99 | 0.003 | 0.001 | 0.002 | 0.002 | 0.002 | 0.005 |
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Table 1. Chemical composition of T2 copper
Material | Mass fraction /% |
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Fe | C | Si | Mn | Cr | Ni | S | P |
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304L | 64.935-70.935 | 0.03 | 1.0 | 2.0 | 18.0-20.0 | 8.0-12.0 | 0.03 | 0.035 |
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Table 2. Chemical composition of 304L stainless steel
Laser power /W | Laser power density /(1012 W·cm-2) | Etching times n |
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10-25 | 3.54-8.84 | 1 | 27.5 | 9.73 | 1,2,3,4,5,6,7,8,9,10,11 | 30-35 | 10.61-12.38 | 1 |
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Table 3. Process parameters for preparing microtexture on 304L stainless steel surface