| Glass is widely used in the modern architecture as its good performances such as good transparency, strong corrosion resistance and high hardness. At present, architectural glass and metal are bonded with glass putty, glass glue and rubber seal strip, these materials are easy to aging. Laser transmission welding develops fast in bonding of transparent material because of its unique advantages. The laser used for welding glass to metal are short pulse laser and ultra short pulse laser. These laser equipments are very expensive. The long pulse laser is widely used in industry. Stainless steel is widely used in construction industry due to its excellent performance and low price. The titanium alloy has many advantages such as high strength, low density and good welding performance. It is a new kind of building material. An experimental study of welding dissimilar materials between transparent architectural glass and stainless steel/titanium alloy using a long pulse laser is reported in this paper.The wetting ability of glass on metal surface has an important effect on bonding of the two materials. First the wetting experiments of glass on stainless steel/titanium alloy were carried out. The influence of wetting process parameters(holding temperature, hold time, oxidation scale, surface roughness) on contact angle were researched. The interface of specimens were observed by scanning electron microscope(SEM). Then the welding experimental scheme was determined. The test of breaking strength was conducted by universal tensile test machine. The influence of process parameters(power, pulse duration, pulse repetition rate, defocus distance, welding speed) on breaking strength were studied. The fracture morphology and microstructure of weldments were analyzed using SEM. The phase formed in welding process was identified by X-ray diffraction(XRD). Finally, we summarized the connecting mechanism between glass and stainless/ titanium alloy under laser irradiation. The results show that: Increasing the holding temperature, holding time and preoxidation of the metal can enhance the wettability between the glass and the stainless steel; The surface roughness has no obvious influence of the contact angle. The wettability of titanium alloy and glass is better than that of stainless steel and glass. The appropriate positive defocus distance is helpful to improve the breaking strength of the weldment, for example +2mm. The maximum breaking strength of the weldment between glass and stainless steel is 67.32 N. The corresponding process parameters are P=165W, TP=2.5ms, f=10Hz, h=+2mm, v=3mm/s. However, the maximum breaking strength of the weldment between glass and titanium alloy is 140.76 N. The corresponding process parameters are P=170W, TP=2.5ms, f=10Hz, h=+2mm, v=3mm/s. The mixed structure of glass and stainless steel/titanium alloy at the interface plays an important role in connecting the two materials, and adhesion particles play a subsidiary role like glue. The breaking strength of the weldment between titanium alloy and glass is higher than that of stainless steel and glass. XRD phase detection show that a chemical reaction take place during the welding of glass and titanium alloy, the new substance is Ti5Si3.With the results and key technology obtained, we could achieve the bonding of glass and stainless steel/titanium alloy rapidly. The research can provide some basis for bonding of glass and metal with laser, and broaden the application field of the long pulse laser. |
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