Tailoring sapphire–Invar welds using burst femtosecond laser
Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CASPeer-Reviewed Publication
Focusing on the engineering challenge of achieving stable, high-strength welding between rough metals surfaces and transparent materials, this work provides an in-depth elucidation of the femtosecond laser welding mechanism for dissimilar materials under non-optical-contact conditions. Through high-speed in situ imaging techniques, it reveals the dynamic coupling between linear absorption in the metal and nonlinear absorption in sapphire during ultrafast laser irradiation. The study further identifies an active interfacial gap filling effect of molten metal, which proactively regulates the free space region at the interface. It clarifies that the welding strength is primarily limited by cracks induced by thermal stress in sapphire, and demonstrates welding performance exceeding 10 MPa between rough Invar alloy and sapphire. These findings offer theoretical guidance and technical support for high-strength, highly stable welding of dissimilar materials.
- Journal
- Light: Advanced Manufacturing
- Funder
- National Key Research and Development Program of China, National Natural Science Foundation of China, Science and Technology Innovation Program of Hunan Province, Changsha Natural Science Foundation