Papers by Keyword: Laser-Welding

Abstract: The present study is focused on joining two ultra-high strength steels plates of 3 mm thickness using laser-welding. Abrasion resistant steel with martensitic structure, tensile strength (R_m) ≥ 2 GPa, and cold-deformed austenitic stainless steel, R_m 1.3 GPa, were used for the dissimilar butt joints. Two different laser energy inputs, 160 and 320 J/mm, were presented during welding. The weld morphology and microstructural evolution of the fusion zone were recorded using optical microscopy and electron back scattering diffraction (EBSD), respectively. The mechanical properties of the dissimilar joints were evaluated by hardness measurements and tensile tests. It was found that fusion zone has undergone a change in morphology and microstructure during welding depending upon the energy input. Analysis of the microstructural evolution in the fusion zone by EBSD examination showed that the presence of a mixture of small austenite grains in a matrix of martensite. The changes in hardness profiles and tensile strength under the experimental parameters were further reported.

Abstract: This paper investigates the effect of the energy input on the microstructure evolution and mechanical properties of laser-welded dissimilar lap joints of cold work-hardened austenitic stainless steel (CW-ASS) and martensitic abrasion resistant steel (AR600). Microstructure characterization of the welds was conducted using optical microscopy and electron backscatter diffraction in a scanning electron microscope. Subsequently, the mechanical properties of the dissimilar lap joints were determined using microhardness measurements and tensile tests. The microstructure observations show that the phase structure in the fusion zone (FZ) is predominantly ferritic at both energy inputs. Besides, the solidification microstructure in the FZ resembles the cast structure composed of cellular and columnar dendrites with exhibiting elemental segregations. The hardness reaches its peak in the FZ. However, the FZ near AR600 steel exhibited higher hardness values than that near CW-ASS. The dissimilar lap joints welded at low energy input 160 J/mm achieved a higher shear strength than those welded at high energy input 320 J/mm due to the softening of the weld in the former lap joint.

Abstract: Laser activated SurgiLux^® technology was examined to determine its suitability as an ocular wound sealant. SurgiLux showed suitable strength and flexibility as well as moisture content for applications in the eye. In comparison to conventional microsuturing complemented with fibrin sealant, application of the SurgiLux technology was up to 5 times faster and the strength of the repaired wounds up to 7 times greater, with a 6 mm incision withstanding 235 mm Hg pressure compared to 120 mm Hg for sutures with fibrin.