Ferritic stainless steel (FSS) is one of the high-temperature materials, used in many industries for sustainable applications such as power plants, automotive, offshore and chemical industries. ...Joining these materials is challenging due to the formation of an intermetallic and the grain growth with high-heat-input welding methods. Laser beam welding (LBW) that uses a low heat input was used successfully to join AISI 409 FSS tubes. In this work the welding speed and focal distance were varied as per a two-factor, three-level face-centred central composite design (FCCCD) to join AISI 409 FSS. A numerical model was developed to correlate the relationship between the ultimate tensile strength (UTS) and LBW process parameters. The validation of the developed model was carried out using the analysis of variance. Both welding speed and focal distance have a significant effect on determining the UTS. The optimised process parameters provided for a better UTS as reported in this paper.
To explore the effect of pulse duration on the micro-morphology and mechanical properties of laser-welded glass joints, a glass welding experiment was carried out. The microstructure of the molten ...layer with different pulse durations was shown by field-emission scanning electron microscopy. The pores and distribution characteristics were analyzed, and the porosity variation rule of the welding layer for different pulse durations was obtained. The line-scan analysis of the joint interface was carried out with a D8-Advance type crystal X-ray diffractometer, and the relationship between the thickness of the reactive wetting layer and the pulse duration was obtained. The hardness and welding strength of the laser-welded glass joints were obtained with a Vickers hardness tester and an electronic universal testing machine. This study can provide a theoretical and experimental basis for the laser welding of glass.
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