Influence of air gap on the sapphire/Invar36 alloy joints by ultrafast laser direct micro-welding
Source abstract
Abstract
The effect of interfacial air gap width on ultrafast laser micro-welding of sapphire to Invar36 alloy was systematically investigated for the first time. To precisely control the air gap width (optical contact, 0.36, 0.84, 1.32, 1.60, and 2.26 μm), ultrafast laser micromachining technology was applied. Small gaps (optical contact to 1.32 μm) promoted material intermixing and mechanical interlocking, while large gaps (1.60–2.26 μm) induced defects such as microcracks and voids. Therefore, shear strength gradually decreased from 242.7 to 13.6 MPa as the gap increased to 1.32 μm, and it suddenly dropped to 0 MPa when the gap was above 1.60 μm. Joint formation was attributed to nano-/micro-particle bridging from laser-induced Invar plasma. In summary, an acceptable gap tolerance between 0.36 and 0.84 μm is recommended for industrial applications, yielding 28–48.5 MPa strength which is compatible with the brazed joints.
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Research context
OpenAlex topics: Welding Techniques and Residual Stresses · Laser and Thermal Forming Techniques · Advanced Welding Techniques Analysis
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
School of Materials Science and Engineering, Shanghai University of Engineering Science 1 , Shanghai 201620,
Shanghai Collaborative Innovation Center of Intelligent Manufacturing Robot Technology for Large Components 2 , Shanghai 201620,
Shanghai Radio Equipment Research Institute 3 , Shanghai 201109,
Faculty of Materials and Manufacturing, Beijing University of Technology 4 , Beijing 100124,
Funding
National Natural Science Foundation of China
References (22)
Show source-provided references
1. Ultrafast laser welding of transparent materials: From principles to applications10.1088/2631-7990/ada7a7 ↗
2. Influence of process parameters on the microstructure and mechanical property of sapphire/invar joints welded by femtosecond laser10.1016/j.matchar.2025.115635 ↗
3. Micro-welding of sapphire and metal by femtosecond laser10.1016/j.ceramint.2023.03.267 ↗
4. Microcrackless weld formation under unilateral melting in laser transmission welding of sapphire and stainless steel10.1016/j.jmapro.2025.02.087 ↗
5. Mechanism and optimization of femtosecond laser welding fused silica and aluminum10.1016/j.apsusc.2023.158327 ↗
6. Micro-welding of non-optical contact sapphire/metal using burst femtosecond laser10.1016/j.matlet.2024.137540 ↗
7. Realization of joints of aluminosilicate glass and 6061 aluminum alloy via picosecond laser welding without optical contact10.3390/ma17174299 ↗
8. Interfacial microstructure and mechanical properties of titanium/sapphire joints brazed with AuSn20 filler metal10.3390/cryst12121687 ↗
9. A novel CoCrNi medium entropy alloy enhanced AgCuTi composite filler to braze kovar alloy and sapphire10.1016/j.matchar.2023.112668 ↗
10. Enhancing sapphire/kovar alloy brazed joint through combined effect of TiB whisker reinforcement and surface micro-nano structures10.1016/j.matchar.2024.114439 ↗
11. Improvement of microstructure and mechanical properties of sapphire/kovar alloy joints brazed with Ag-Cu-Ti composite filler by adding B powders10.1016/j.jmapro.2023.05.050 ↗
12. Enhanced joint through significant diffusion and molten pool regions in fused silica to aluminum alloy welding by femtosecond mJ-pulses10.1007/s00170-023-12325-w ↗
13. Ultrastrong dissimilar glass-ceramic to Fe-36Ni alloy joints using ultrafast laser micro-welding10.1016/j.jmapro.2025.06.096 ↗
14. Welding threshold in ultrafast laser welding of quartz glass and 304 stainless steel10.1016/j.optlastec.2024.111622 ↗
15. Tuning the optical reflection property of metal surfaces via micro-nano particle structures fabricated by ultrafast laser10.1016/j.apsusc.2015.10.069 ↗
16. Angle-independent colorization of copper surfaces by simultaneous generation of picosecond-laser-induced nanostructures and redeposited nanoparticles10.1063/1.4869456 ↗
17. Patternable fabrication of hyper-hierarchical metal surface structures for ultrabroadband antireflection and self-cleaning10.1016/j.apsusc.2018.07.017 ↗
18. High-energy ions produced in explosions of superheated atomic clusters10.1038/386054a0 ↗
19. Explosive phase transformation in excimer laser ablation10.1016/S0169-4332(97)00619-3 ↗
20. Ultrashort laser ablation of solid matter in vacuum: A comparison between the picosecond and femtosecond regimes10.1088/0953-4075/38/20/L01 ↗
21. Characterization of laser ablation of solid targets with near-infrared laser pulses of 100 fs and 1 ps duration10.1016/j.apsusc.2005.06.045 ↗
22. Understanding the ultrashort laser microwelding process of ceramics to metals by numerical and experimental investigations10.2351/7.0001638 ↗