Joining of Soda Lime Silicate Glass TO TI6AL4V Alloy in Air by Controlled Heat Treatments

Soda lime silicate glass was joined to Ti6Al4V alloy in air by heat treatment at 800°C for 10, 20 and 30 min and by subsequent cooling to room temperature with a controlled cooling rate. Stresses, due to thermal expansion mismatch, have developed at glass-metal interface after high temperature joining and cooling down to room temperature. The finite element calculations, performed using ANSYS 14 software, suggested that the glass-metal interface was experiencing rather low maximal and minimal principal stresses due to joining. Highest maximal principal stress level was about 25 MPa and lowest minimal principal stress level was about -40 MPa for used sandwich sample profiles. Heat treatment duration affected tensile bonding strength and interfacial reaction between the glass and the Ti alloy. Scanning electron microscope analysis of glass-alloy joining interface showed that a secondary K, Ca, Ti rich sodium silicate phase was forming in glass, starting at glass alloy interface and that it was growing with the increase in heat treatment duration. Low joining stress levels at the glass-alloy interface for used sandwich sample profile and good bonding between the soda lime silicate glass and Ti6Al4V alloy resulted in creation of successful soda lime silicate glass-Ti6Al4V joints.